WO2025016171A1 - Three-dimensional fluorescence detection apparatus - Google Patents

Abstract

A three-dimensional fluorescence detection apparatus, comprising a monochromatic array light source, a first lens group, a fluorescence detection apparatus, a light intensity detection apparatus, and a control and data processing module. The monochromatic array light source is used for emitting excitation light, and comprises N monochromatic light sources, wherein the excitation light comprises light of N wavelengths, and covers a first waveband; the first lens group is used for converging the excitation light to form an excitation region in which a sample to be subjected to detection is placed; the fluorescence detection apparatus is used for outputting fluorescence spectrum data; the light intensity detection apparatus is used for outputting transmission light intensity data; and the control and data processing module is used for controlling the monochromatic array light source to emit excitation light, and is also used for determining the three-dimensional fluorescence spectrum and absorption spectrum of said sample. Fluorescence spectrum data and transmission light intensity data of a sample are acquired by means of synchronous sampling, such that the absorption spectrum and three-dimensional fluorescence spectrum of the sample are synchronously detected. Thus, the accuracy of substance detection for the sample can be improved, and the size, cost and power consumption of a system are also reduced.

Description

A three-dimensional fluorescence detection device

This application claims the priority of the Chinese patent application filed with the State Intellectual Property Office of China on July 14, 2023, with application number 202310864491.3, and the priority of the Chinese patent application with the invention name “A three-dimensional fluorescence detection device”, all contents of which are incorporated by reference in this application.

Technical Field

The present application relates to the field of light perception, and more specifically, to a three-dimensional fluorescence detection device.

Background Art

Using spectra to detect the composition and content of substances has always been an important direction in the field of light perception. The most commonly used spectral detection technology is to analyze its absorption spectrum and fluorescence spectrum. The basic detection principle is to use a light beam to pass through or illuminate the sample. The material components in the sample will absorb photons in a specific spectrum, causing the spectrum of the incident light beam to change, or the material in the sample will absorb photons and then radiate fluorescence in a specific spectrum. The composition and content information of the material in the sample can be determined by studying the absorption spectrum transmitted by the sample or the fluorescence spectrum radiated by the sample.

In the actual detection process, unknown samples are often complex mixtures of multiple substances. For example, when detecting organic pollutants in water, the spectral information of various substances is superimposed on each other. The information provided by a simple fluorescence spectrum or absorption spectrum is often relatively single and cannot accurately identify and analyze the samples.

As a kind of "fingerprint spectrum", the three-dimensional fluorescence spectrum is formed by adding the excitation wavelength dimension to the usual two-dimensional fluorescence spectrum, forming a three-dimensional matrix spectrum (Excitation-Emission-Matrix Spectra, EES). Generally, the y-axis corresponds to the excitation wavelength, the x-axis corresponds to the fluorescence emission wavelength, and the z-axis corresponds to the fluorescence intensity. The three-dimensional fluorescence spectrum collects the total fluorescence data of the sample, which has special advantages for analyzing the material category of the sample and extracting the sample component information.

However, the acquisition of the three-dimensional fluorescence spectrum of a substance requires the use of expensive and bulky laboratory professional instruments. These instruments generally require professional personnel to operate and maintain, and it is difficult to achieve commercial and industrial applications outside the laboratory. In addition, these three-dimensional fluorescence spectrum detection instruments can often only obtain three-dimensional fluorescence spectra. If you want to obtain the absorption spectrum of the sample, you need to use an absorption spectrum detection instrument. For some samples with unstable properties, such as suspensions, colloids, etc., it is impossible to simultaneously obtain the absorption spectrum and three-dimensional fluorescence spectrum of the sample under the same state of the sample. Therefore, the miniaturization, low cost, and easy operation of three-dimensional fluorescence detection instruments have been hot research directions in recent years; and how to obtain the absorption spectrum and three-dimensional fluorescence spectrum of the sample under the same experimental conditions is also a problem that needs to be solved in recent years.

Summary of the invention

The present application provides a three-dimensional fluorescence detection device. In which, a monochromatic array light source is used to replace the traditional high-power xenon light source and monochromator, which greatly reduces the system volume, cost and power consumption, so as to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology; the present application also synchronously samples through the fluorescence detection device and the light intensity detection device, and synchronously detects the absorption spectrum and three-dimensional fluorescence spectrum of the sample, which is conducive to improving the accuracy of sample material detection.

In the first aspect, a three-dimensional fluorescence detection device is provided, which includes a monochromatic array light source, a first lens group, a fluorescence detection device, a light intensity detection device, and a control and data processing module. Specifically, the monochromatic array light source is used to emit excitation light, the monochromatic array light source includes N monochromatic light sources, the monochromatic light source is used to emit light with a single wavelength, the excitation light includes N wavelengths of light and covers a first band, wherein N is a positive integer greater than or equal to 2, and the first band has an intersection with the fluorescence excitation band of the sample to be tested; the first lens group is used to receive the excitation light, and converge and overlap the excitation light to form an excitation area, wherein the incident positions of the N beams of light in the excitation light entering the first lens group are different, and the sample to be tested is placed in the excitation area; the fluorescence detection device is used to receive the fluorescence signal generated by the sample to be tested and output fluorescence spectrum data, and the light intensity detection device is used to receive the excitation light transmitted from the sample to be tested and output transmission light intensity data; the control and data processing module is used to control the monochromatic array light source to emit excitation light, and is also used to receive fluorescence spectrum data and transmission light intensity data, and determine the three-dimensional fluorescence spectrum and absorption spectrum of the sample to be tested.

Based on the technical solution, a monochromatic array light source is used to emit excitation light. The monochromatic array light source includes N monochromatic light sources, each of which emits light of one wavelength. The excitation light band emitted by the entire monochromatic array light source covers the first band. The first lens group converges the excitation light emitted by the array light source to form an excitation area for placing the sample to be tested so that the sample generates fluorescence through stimulated radiation. Through the fluorescence detection device and The light intensity detection device synchronously samples and obtains the fluorescence spectrum data and transmitted light intensity data of the sample, and synchronously detects the absorption spectrum and three-dimensional fluorescence spectrum of the sample, which can improve the accuracy of sample material detection, while also reducing the size, cost and power consumption of the system, so as to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology.

It should be understood that in the embodiment of the present application, the fluorescence spectrum data includes the composition of the fluorescence bands in the fluorescence signal and the light intensity of the fluorescence in each band.

It should be understood that the light intensity detection device can be arranged on one side of the excitation light transmission direction, and the fluorescence detection device can be arranged on one side of the excitation area, and the one side of the excitation light transmission direction and the one side of the excitation area are adjacent.

It should be understood that in the embodiments of the present application, the first band includes the infrared-near infrared-ultraviolet UV-VIS-NIR band. Specifically, in practical applications, the coverage range of the first band can be determined according to the characteristics of the stimulated radiation of the sample to be tested to ensure that the sample to be tested generates a fluorescence signal when stimulated radiation is generated in the excitation area. The present application does not make any special limitations on this.

It should be understood that the monochromatic array light source is composed of N monochromatic light sources, and the N wavelengths of light emitted by the N monochromatic light sources have a first interval in sequence, and the spectrum of the excitation light emitted by the overall monochromatic array light source covers the first band. In the embodiment of the present application, N includes a positive integer greater than or equal to 3, and the present application does not make any special limitation on this.

It should be understood that when the first interval is smaller, that is, the number of monochromatic light sources in the first band is greater, and the value of N is larger, the more fluorescence spectrum data and transmitted light intensity data points are obtained, and the accuracy of the generated three-dimensional fluorescence spectrum and absorption spectrum is higher. In the embodiment of the present application, the first interval includes 10 to 20 nm. The specific value of the first interval can be determined according to the characteristics of the stimulated radiation of the sample to be tested to ensure that the acquired three-dimensional fluorescence spectrum data and absorption spectrum have a certain continuity. The present application does not make any special limitation on this.

It should be understood that when N=1, that is, the monochromatic array light source emits excitation light with only one wavelength, the sample to be tested generates a fluorescence signal due to the excitation light, the fluorescence spectrum data and transmitted light intensity data received by the control and data processing module only include data points of one wavelength, and the wavelength coordinates of the generated three-dimensional fluorescence spectrum and absorption spectrum only include data points of one wavelength.

In combination with the first aspect, in certain implementations of the first aspect, the N wavelengths of light emitted by N monochromatic light sources have a first wavelength interval in sequence, which also includes that when N is greater than or equal to 3, the nth monochromatic light source emits light with a first wavelength, the n+1th monochromatic light source emits light with a second wavelength, and the n+2th monochromatic light source emits light with a third wavelength, and n, n+1, and n+2 are positive integers belonging to N; wherein the first wavelength and the second wavelength differ by a first value, the second wavelength and the third wavelength differ by a second value, and the first wavelength interval includes the first value and the second value.

Based on the technical solution, a monochromatic array light source is used to emit excitation light, and the monochromatic array light source includes N monochromatic light sources, each of which emits light of one wavelength, and the excitation light band emitted by the entire monochromatic array light source covers the first band. The first lens group converges the excitation light emitted by the array light source to form an excitation area, which is used to place the sample to be tested so that the sample generates fluorescence through stimulated radiation. The fluorescence spectrum data and transmitted light intensity data of the sample are obtained by synchronous sampling through the fluorescence detection device and the light intensity detection device, and the absorption spectrum and three-dimensional fluorescence spectrum of the sample are synchronously detected, which can improve the accuracy of sample material detection, while also reducing the volume, cost and power consumption of the system, so as to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology.

It should be understood that the first value and the second value can be the same value or different values, that is, the wavelength interval between each monochromatic light source can be fixed, and the excitation light emitted by N monochromatic light sources covers the first band; it is also possible that the wavelength interval between each monochromatic light source is different, and the excitation light emitted by N monochromatic light sources covers the first band; the present application does not make any special limitation on this.

In combination with the first aspect, in certain implementations of the first aspect, light emitted by N monochromatic light sources is directly coupled through N optical fibers, respectively, the N optical fibers transmit the excitation light emitted by the monochromatic array light source to the first lens group, and the output ends of the N optical fibers are arranged nonlinearly.

Based on the technical solution, the light emitted by N monochromatic light sources is directly coupled through N optical fibers respectively, and the coupled excitation light is transmitted to the first lens group through the optical fiber bundle, and the output end of the optical fiber bundle formed by the N optical fibers is arranged nonlinearly. By adopting the method of directly coupling the monochromatic light source with the optical fiber, no other coupling device is required, which simplifies the design of the overall device, especially when the number of monochromatic light sources is large, that is, N is large, the direct coupling method can greatly simplify the operations such as aligning the optical path. By synchronously sampling and acquiring the fluorescence spectrum data and the transmitted light intensity data of the sample through the fluorescence detection device and the light intensity detection device, and synchronously detecting the absorption spectrum and the three-dimensional fluorescence spectrum of the sample, the accuracy of the sample material detection can be improved, while also reducing the volume, cost and power consumption of the system, so as to facilitate the integration and application of the three-dimensional fluorescence spectrum detection technology.

In combination with the first aspect, in certain implementations of the first aspect, light emitted by N monochromatic light sources is coupled into N optical fibers through N coupling lenses respectively, the N optical fibers transmit the excitation light emitted by the monochromatic array light source to the first lens group, and the output ends of the N optical fibers are arranged nonlinearly.

Based on this technical solution, the light emitted by N monochromatic light sources is coupled into N optical fibers through N coupling lenses, and the coupled excitation light is transmitted to the first lens group through the optical fiber bundle. The output end of the optical fiber bundle formed by the N optical fibers is arranged nonlinearly. The use of coupling lenses to couple the light emitted by the monochromatic light source into the N optical fibers can further improve the optical fiber coupling efficiency and the beam quality of the excitation light beam incident on the sample area. The fluorescence spectrum data and the transmitted light intensity data of the sample are obtained by synchronous sampling through the fluorescence detection device and the light intensity detection device. By detecting the absorption spectrum and three-dimensional fluorescence spectrum of the sample in steps, the accuracy of sample material detection can be improved, while also reducing the volume, cost and power consumption of the system, so as to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology.

In combination with the first aspect, in certain implementations of the first aspect, the output ends of the N optical fibers are arranged in a closely packed manner, wherein the closely packed manner includes that the surface area of the output end cross section formed by the arrangement of the N optical fibers is the smallest, and the output end cross section includes a circle.

Based on this technical solution, the output ends of N optical fibers are closely arranged to ensure that the surface area of the end face is minimized and the end face of the output end is circular. The beam quality of the excitation light beam incident on the sample area can be further improved. The fluorescence spectrum data and the transmitted light intensity data of the sample are obtained by synchronous sampling through the fluorescence detection device and the light intensity detection device, and the absorption spectrum and three-dimensional fluorescence spectrum of the sample are synchronously detected, which can improve the accuracy of sample material detection, while also reducing the volume, cost and power consumption of the system, so as to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology.

In combination with the first aspect, in certain implementations of the first aspect, the three-dimensional fluorescence detection device also includes a second lens group, which is used to converge the excitation light transmitted from the sample to be tested to a receiving target surface of the light intensity detection device, and the diameter of the light spot formed by the convergence of the excitation light is less than or equal to the diameter of the photosensitive area of the receiving target surface.

Based on the technical solution, the three-dimensional fluorescence detection device also includes a second lens group, and the excitation light transmitted from the sample will diverge again, and the divergent transmitted light will converge again through the second lens group and converge to the receiving target surface of the light intensity detection device. The fluorescence spectrum data and transmitted light intensity data of the sample are synchronously sampled by the fluorescence detection device and the light intensity detection device, and the absorption spectrum and three-dimensional fluorescence spectrum of the sample are synchronously detected, which can improve the accuracy of sample material detection, while also reducing the volume, cost and power consumption of the system, so as to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology.

In combination with the first aspect, in certain implementations of the first aspect, the control and data processing module is used to control the monochromatic array light source to emit excitation light, and the control and data processing module sends a driving signal to the monochromatic array light source, and the driving signal includes a square wave pulse signal. The driving signal is used to drive N monochromatic light sources to emit light in sequence, and the light emission duration of the monochromatic light source is the pulse duration of the square wave pulse signal.

Based on this technical solution, the N monochromatic light sources in the array light source are driven to emit light in sequence, and the fluorescence detection device and the light intensity detection device also receive the detected fluorescence signals and light intensity signals in sequence, so that the fluorescence spectrum data and the transmitted light intensity data correspond to the light wavelength of the monochromatic light source one by one. By synchronously sampling and acquiring the fluorescence spectrum data and the transmitted light intensity data of the sample through the fluorescence detection device and the light intensity detection device, and synchronously detecting the absorption spectrum and the three-dimensional fluorescence spectrum of the sample, the accuracy of the sample material detection can be improved, while also reducing the volume, cost and power consumption of the system, so as to facilitate the integration and application of the three-dimensional fluorescence spectrum detection technology.

In combination with the first aspect, in certain implementations of the first aspect, the control and data processing module is further used to send a synchronization trigger instruction to the fluorescence detection device to start the fluorescence detection device to sequentially receive the pulse fluorescence signals generated by the excitation area.

Based on this technical solution, the N monochromatic light sources in the array light source are driven to emit light in sequence, and the fluorescence detection device also receives the synchronous trigger instruction synchronously, starts to detect the fluorescence signal and converts the fluorescence spectrum data. The fluorescence spectrum data and the transmitted light intensity data of the sample are synchronously sampled by the fluorescence detection device and the light intensity detection device, and the absorption spectrum and three-dimensional fluorescence spectrum of the sample are synchronously detected, which can improve the accuracy of sample material detection, and at the same time reduce the volume, cost and power consumption of the system, so as to facilitate the integration and application of the three-dimensional fluorescence spectrum detection technology.

In combination with the first aspect, in certain implementations of the first aspect, the fluorescence detection device includes a fiber optic probe and a spectrometer, the fiber optic probe is used to obtain the fluorescence signal generated in the excitation area, and the spectrometer is used to obtain the composition of the fluorescence bands in the fluorescence signal and the light intensity of the fluorescence in each band.

Based on the technical solution, the fluorescence detection device includes an optical fiber probe and a spectrometer. The optical fiber probe is arranged on one side of the sample area to obtain the fluorescence signal generated by the stimulated radiation of the sample. After receiving the fluorescence signal, the spectrometer converts the fluorescence signal into fluorescence spectrum data. The fluorescence spectrum data includes the composition of the band and the light intensity corresponding to each band. The fluorescence spectrum data and the transmitted light intensity data of the sample are obtained by synchronous sampling of the fluorescence detection device and the light intensity detection device, and the absorption spectrum and three-dimensional fluorescence spectrum of the sample are synchronously detected, which can improve the accuracy of sample material detection, while also reducing the volume, cost and power consumption of the system, so as to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology.

In combination with the first aspect, in certain implementations of the first aspect, the fiber optic probe includes a single-core fluorescent fiber optic probe, the input end of the single-core fluorescent fiber optic probe directly detects the fluorescence signal generated by the excitation region, and the output end of the single-core fluorescent fiber optic probe is directly connected to the fiber optic probe interface of the spectrometer.

Based on this technical solution, the optical fiber probe includes a single-core fluorescent optical fiber probe, the input end of the probe is set on one side of the excitation region to detect the fluorescent signal generated by the sample, and the output end of the probe is directly connected to the spectrometer. The fluorescence spectrum data and the transmitted light intensity data of the sample are obtained by synchronous sampling through the fluorescence detection device and the light intensity detection device, and the absorption spectrum and three-dimensional fluorescence spectrum of the sample are synchronously detected, which can improve the accuracy of sample material detection, while also reducing the volume, cost and power consumption of the system, so as to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology.

In combination with the first aspect, in some implementations of the first aspect, the optical fiber probe includes a multi-core fluorescent optical fiber probe, and the multi-core fluorescent optical fiber probe includes three or more single-core optical fibers, and the single-core optical fibers are arranged in a closely arranged manner to form an input end of the multi-core fluorescent probe, and the input end is used to detect the fluorescent signal generated by the excitation area; the single-core optical fibers are arranged in a linear manner to form an output end of the multi-core fluorescent probe. The output end is connected to the optical fiber probe interface of the spectrometer.

Based on this technical solution, the optical fiber probe includes a multi-core fluorescent optical fiber probe. The input end of the probe is a tightly arranged multi-core optical fiber, and the end face of the input end is circular; the output end is linearly arranged according to the slit interface of the spectrometer to further reduce light loss. The fluorescence spectrum data and transmitted light intensity data of the sample are obtained by synchronous sampling through the fluorescence detection device and the light intensity detection device, and the absorption spectrum and three-dimensional fluorescence spectrum of the sample are synchronously detected, which can improve the accuracy of sample material detection, while also reducing the volume, cost and power consumption of the system, so as to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology.

In combination with the first aspect, in certain implementations of the first aspect, the detection distance between the input end of the optical fiber probe and the excitation region includes
2×d×NA＝D;

Wherein, d is the detection distance, NA is the numerical aperture of the fiber probe, and D is the diameter of the spot formed by the excitation light converged in the excitation area.

Based on this technical solution, the excitation light is converged and overlapped through the first lens group to form an excitation area. The spot diameter of the excitation area is D. The optical fiber probe is set on one side of the excitation area, and the detection distance between the optical fiber probe and the excitation area should satisfy 2×d×NA＝D; wherein d is the detection distance, and NA is the numerical aperture of the optical fiber probe. The optical fiber probe is at a suitable detection distance so that the cone solid angle received by the probe covers the entire fluorescence excitation area to increase the detection efficiency. The fluorescence spectrum data and the transmitted light intensity data of the sample are obtained by synchronously sampling the fluorescence detection device and the light intensity detection device, and the absorption spectrum and three-dimensional fluorescence spectrum of the sample are synchronously detected, which can improve the accuracy of sample material detection, while also reducing the volume, cost and power consumption of the system, so as to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology.

In combination with the first aspect, in certain implementations of the first aspect, the light intensity detection device includes a photodetector and an amplifier circuit, the photodetector is used to receive excitation light transmitted from the sample to be tested and convert the received light signal into an electrical signal; the amplifier circuit is used to amplify the electrical signal.

Based on the technical solution, the light intensity detection device includes a photodetector and an amplifying circuit. The receiving target surface of the light intensity detector receives the transmitted light beam after the second lens group converges, and converts the received light signal into an electrical signal. The amplifying circuit amplifies the electrical signal so that the control and data processing module can obtain the transmitted light intensity data. The fluorescence spectrum data and the transmitted light intensity data of the sample are obtained by synchronously sampling the fluorescence detection device and the light intensity detection device, and the absorption spectrum and the three-dimensional fluorescence spectrum of the sample are synchronously detected, which can improve the accuracy of the sample material detection, and also reduce the volume, cost and power consumption of the system, so as to facilitate the integration and application of the three-dimensional fluorescence spectrum detection technology.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of a commonly used high-power xenon lamp three-dimensional fluorescence detection device provided in an embodiment of the present application;

FIG2 is a schematic structural diagram of a commonly used LED array three-dimensional fluorescence detection device provided in an embodiment of the present application;

FIG3 is a schematic diagram of the structure of a three-dimensional fluorescence detection device provided in an embodiment of the present application;

FIG4 is a schematic diagram of a light source coupling method in a three-dimensional fluorescence detection device provided in an embodiment of the present application;

FIG5 is a schematic diagram of another light source coupling method in a three-dimensional fluorescence detection device provided in an embodiment of the present application;

FIG6 is a schematic diagram of the structure of a lens group in a three-dimensional fluorescence detection device provided in an embodiment of the present application;

FIG7 is a schematic diagram of the structure of a spectrometer in a three-dimensional fluorescence detection device provided in an embodiment of the present application;

FIG8 is a schematic diagram of the structure of an optical fiber probe in a three-dimensional fluorescence detection device provided in an embodiment of the present application;

9 is a schematic diagram of the structure of an optical fiber probe in another three-dimensional fluorescence detection device provided in an embodiment of the present application;

FIG10 is a schematic diagram of a driving signal of an array light source in a three-dimensional fluorescence detection device provided in an embodiment of the present application;

FIG11 is a three-dimensional fluorescence spectrum generated by detecting a sample using a three-dimensional fluorescence detection device provided in an embodiment of the present application;

FIG. 12 is an absorption spectrum generated by detecting a sample using a three-dimensional fluorescence detection device provided in an embodiment of the present application.

DETAILED DESCRIPTION

The technical solution in this application will be described below in conjunction with the accompanying drawings.

It should be noted that, in the description of the embodiments of the present application, unless otherwise specified, "/" means or, for example, A/B can mean A or B; "and/or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and/or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two, and "at least one" and "one or more" mean one, two or more. The singular expressions "a", "an", "said", "above", "the" and "this" are intended to also include expressions such as "one or more", unless there is a clear indication to the contrary in the context.

References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of the present application include a particular feature, structure or characteristic described in conjunction with the embodiment. In some embodiments, in some embodiments, in some other embodiments, in some other embodiments, etc., do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

In the description of the embodiments of the present application, the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "vertical" and "horizontal" are defined relative to the directions or positions of the components schematically placed in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, rather than indicating or implying that the device or component referred to must have a specific direction, or be constructed and operated in a specific direction. They may change accordingly according to changes in the directions of the components placed in the drawings, and therefore cannot be understood as limitations on the present application.

In the embodiments of the present application, the same reference numerals are used to represent the same components or the same components. In addition, the components in the drawings are not drawn to scale, and the sizes and dimensions of the components shown in the drawings are only exemplary and should not be understood as limiting the present application.

Spectroscopic technology has always been one of the important means to analyze the composition and content of substances. Absorption spectroscopy and fluorescence spectroscopy are the two most commonly used spectral techniques. Among them, the absorption spectrum is a spectrum produced when the incident light beam passes through the sample and the substance in the sample absorbs photons in a specific spectral band, resulting in the light intensity of certain spectral bands of the outgoing light beam being different from the light intensity of the spectral band of the incident light beam; the fluorescence spectrum is a spectrum produced when the incident light beam irradiates the sample and the substance in the sample absorbs photons and then radiates fluorescence in a specific spectral band. The absorption spectrum and fluorescence spectrum of the sample can be used to infer the composition and content of the substance in the sample. In practical applications, the unknown samples to be detected are often complex mixtures of multiple molecules. The spectral information of various molecules is superimposed, resulting in incomplete information in simple absorption spectra or fluorescence spectra, making it difficult to accurately identify and analyze the sample components.

As a "fingerprint spectrum", three-dimensional fluorescence spectroscopy has special advantages in solving the above problems. It is based on two-dimensional fluorescence spectroscopy, and adds the excitation wavelength dimension to form a three-dimensional matrix spectrum (Excitation-Emission-Matrix Spectra, EES). Generally, the y-axis corresponds to the excitation wavelength, the x-axis corresponds to the fluorescence emission wavelength, and the z-axis corresponds to the fluorescence intensity. Three-dimensional fluorescence spectroscopy can collect the overall fluorescence data of the sample, and has special advantages in analyzing the substance category and extracting its component information. However, traditional three-dimensional fluorescence spectroscopy detection technology relies on expensive and bulky laboratory professional instruments, which require professional personnel to operate and maintain, and cannot enter the industrial and consumer fields. In addition, these three-dimensional fluorescence spectroscopy detection instruments can often only obtain three-dimensional fluorescence spectra. If you want to obtain the absorption spectrum of the sample, you need to use an absorption spectrum detection instrument. For some samples with unstable properties, such as suspensions, colloids, etc., it is impossible to simultaneously obtain the absorption spectrum and three-dimensional fluorescence spectrum of the sample in the same state of the sample. Therefore, the miniaturization, low cost and easy operation of three-dimensional fluorescence detection instruments have been hot research directions in recent years; and how to obtain the absorption spectrum and three-dimensional fluorescence spectrum of the sample under the same experimental conditions is also a problem that needs to be solved in recent years.

FIG1 is a schematic diagram of the structure of a commonly used high-power xenon lamp three-dimensional fluorescence detection device provided in an embodiment of the present application. The three-dimensional fluorescence device in the figure uses a high-power xenon lamp as a light source, and the power consumption is generally 150W-300W. The spectrum range emitted by the xenon lamp covers the ultraviolet-visible-near infrared (UV-VIS-NIR) band. As shown in the figure, the wide-spectrum light emitted by the xenon lamp is incident on the sample area after being scanned by a monochromator and converged by a lens group, wherein the monochromator 1 is used for time-sharing scanning and outputting a monochromatic excitation light of 200-700nm. The monochromatic excitation light is focused by a lens group to excite the sample to generate a wide-spectrum fluorescence radiation. The generated wide-spectrum fluorescence signal is filtered out by a filter to remove the wavelength of the excitation light. The filtered fluorescence signal is incident on the monochromator 2 again for time-sharing scanning to obtain light signals of different wavelengths in the fluorescence signal. The light signals of different wavelengths output from the time-sharing scanning of the monochromator 2 are then measured by a photomultiplier tube to measure their light intensity values. In the high-power xenon lamp three-dimensional fluorescence detection device shown in the figure, monochromator 1 performs time-sharing scanning on the wavelength of the excitation light emitted by the xenon lamp light source to obtain the excitation wavelength value (i.e., the y-axis), monochromator 2 performs time-sharing scanning on the excited fluorescence signal and obtains the fluorescence wavelength value (i.e., the x-axis), and the photomultiplier tube measures the light intensity of the fluorescence signal output by monochromator 2 in time to obtain the fluorescence intensity value (i.e., the z-axis). The device described in the figure constructs a three-dimensional fluorescence spectrum based on the above three dimensions.

Although the device in Figure 1 can obtain a three-dimensional fluorescence spectrum of a sample, the large size and high cost of the high-power xenon lamp and monochromator limit the usage scenarios of the device and its portability. In addition, due to the high cost, it can only be used to test samples in laboratories and has few commercial applications. It is also unable to detect the absorption spectrum of the sample.

FIG2 is a schematic diagram of the structure of a commonly used LED array three-dimensional fluorescence detection device provided in an embodiment of the present application. The three-dimensional fluorescence device in the figure uses a light-emitting diode (LED) array as a light source, and each LED outputs quasi-monochromatic excitation light. The wavelength interval of the excitation light output by each LED is about 10 nm. The excitation light emitted by each LED is coupled to the corresponding optical fiber through the corresponding coupling lens, and the excitation light emitted by N LEDs is coupled to N optical fibers through N coupling lenses; wherein, the N LEDs form an LED light source array, that is, the light output by the LED array is coupled to the optical fiber bundle through the coupling lens group, and the output ends of the N optical fibers are combined into an optical fiber cable connected to the sample pool. The LEDs in the LED light source array are lit up in time to emit excitation light, and the excitation light is transmitted to the sample pool through the optical fiber to excite the sample to radiate fluorescence. The generated fluorescence signal is received again through the optical fiber cable and input into the monochromator. The monochromator performs wavelength scanning on the fluorescence signal to obtain the fluorescence spectrum, and the photomultiplier tube measures the light intensity of the corresponding fluorescence signal. In this device, the optical fiber of the excitation light connected to the sample pool The wiring corresponds to the fluorescence signal receiving optical fiber wiring one by one, that is, the fluorescence signal excited by each monochromatic LED is received by the corresponding receiving optical fiber, and then transmitted to the monochromator and photomultiplier tube by this optical fiber. In the process of using this device to detect three-dimensional fluorescence spectrum, the LED light source array is lit in time-sharing, reaching the sample pool to excite the sample, and then the monochromator is used to scan the fluorescence signal after being excited by the sample pool in time-sharing, and the wavelength and light intensity information of the fluorescence signal are obtained to generate a three-dimensional fluorescence spectrum.

Although the device in FIG2 uses an LED array light source instead of a high-power xenon lamp light source to reduce the volume of the light source to a certain extent, in the device shown in FIG2, both the excitation light input end and the fluorescence signal receiving end of the sample pool use optical fiber cables, and the incident excitation light and the emitted fluorescence signal need to be relatively closely aligned. When the number of LEDs in the LED array light source is large, the design of the device is difficult; in addition, the fluorescence areas excited by different samples under the action of the excitation light are not the same, that is, the propagation direction of the generated fluorescence signal will change, that is, the propagation direction of the fluorescence signal is different from the propagation direction of the excitation light, and the optical fiber cable cannot receive the fluorescence signal in the fluorescence action area. The device shown in FIG2 is more suitable for uniform liquid samples, and it is also impossible to detect the absorption spectrum of the sample.

Three-dimensional fluorescence spectroscopy is a new type of fingerprint spectrum, which has important applications in the fields of agricultural products, chemical products and water quality testing. However, the current three-dimensional fluorescence spectroscopy detection equipment is mainly professional laboratory equipment, which is large in size and expensive, and it is difficult to popularize and promote. In recent years, some monochromatic light sources have made great progress in the ultraviolet to near-infrared spectrum, such as LED light sources. At present, deep ultraviolet LEDs can already have milliwatt-level light radiation capabilities at a wavelength of 220nm.

Therefore, the present application proposes a three-dimensional fluorescence detection device based on a monochromatic array light source. The monochromatic array light source is used to replace the traditional high-power xenon lamp light source and monochromator, which greatly reduces the system volume, cost and power consumption, so as to facilitate the integration and application of three-dimensional fluorescence spectrum detection technology; the present application also synchronously samples through the fluorescence detection device and the light intensity detection device, and synchronously detects the absorption spectrum and fluorescence spectrum of the sample, which is conducive to improving the accuracy of sample material detection.

The three-dimensional fluorescence detection device includes a monochromatic array light source, a first lens group, a fluorescence detection device, a second lens group, a light intensity detection device, and a control and data processing module. The monochromatic array light source is composed of N monochromatic light sources emitting a single wavelength, and the wavelength interval between each monochromatic light source is 10 to 20 nm. The wavelength range covered by the overall array light source can range from deep ultraviolet (e.g., 200 nm) to near infrared (e.g., 1000 nm). The array light source emits excitation light under the drive of the control and data processing module, and the light emitted by the N monochromatic light sources is coupled into N optical fibers. The output ends of the N optical fibers are closely arranged to form a combined multi-core optical fiber. The combined multi-core optical fiber inputs the excitation light emitted by the LED array light source into the first lens group, and the first lens group converges the excitation light to the sample area, and the sample area is used to place the sample to be tested. The sample to be tested is excited by the excitation light emitted by the monochromatic array light source in the sample area, and the stimulated radiation generates a fluorescence signal. A fluorescence detection device is set in the sample area to detect the fluorescence signal generated by the stimulated radiation of the sample. The fluorescence detection device converts the received fluorescence signal into fluorescence spectrum data. The fluorescence spectrum data includes the wavelength of each monochromatic fluorescence in the fluorescence signal and the light intensity corresponding to each wavelength of fluorescence. The control and data processing module combines the fluorescence spectrum data of the sample output by the fluorescence detection device with the N excitation light wavelengths emitted by N monochromatic light sources to form a three-dimensional fluorescence spectrum of the sample.

For samples that can be penetrated by the excitation light, the excitation light is transmitted through the sample area and then diverged again. The diverged excitation light passes through the second lens group, and the second lens group converges the excitation light to the receiving target surface of the light intensity detection device. The light intensity detection device is used to detect the light intensity corresponding to each single wavelength light beam in the excitation light after it passes through the sample area. The control and data processing module obtains the transmitted light intensity data of the sample detected by the light intensity detection device to form the absorption spectrum of the sample.

In one embodiment, the monochromatic array light source includes N single-wavelength LEDs, each LED has a wavelength interval of 10 to 20 nm, and the wavelength range covered by the overall array light source can range from deep ultraviolet (e.g., 200 nm) to near infrared (e.g., 1000 nm). The single-wavelength excitation light emitted by each LED light source is coupled into an optical fiber, ultimately forming a combined multi-core optical fiber of N optical fibers.

In one embodiment, the monochromatic array light source includes N semiconductor laser diodes (LDs), each LD has a wavelength interval of 10 to 20 nm, and the wavelength range covered by the overall array light source can range from deep ultraviolet (e.g., 200 nm) to near infrared (e.g., 1000 nm). The single-wavelength excitation light emitted by each LD light source is coupled into an optical fiber, ultimately forming a combined multi-core optical fiber of N optical fibers.

It should be understood that the monochromatic array light source of the present application also includes other monochromatic light sources, which are not listed one by one in the present application. The specific scope of protection shall be subject to the claims, and the present application does not make any special limitation on this.

The following describes a specific implementation of the technical solution of the present application by taking a monochromatic LED array light source as an example.

Fig. 3 is a schematic diagram of the structure of a three-dimensional fluorescence detection device provided by an embodiment of the present application. Among them, N LED light sources are coupled into N optical fibers through their respective coupling modules, and the output ends of the N optical fibers are closely packed to form a combined multi-core optical fiber. The control and data processing module sends a time-sharing pulse signal to the LED array light source, and drives the N LEDs to emit pulse light in sequence in a time-sharing manner; at the same time, the control and data processing module also sends a synchronization trigger signal to the fluorescence detection device, triggering the fluorescence detection device to collect the fluorescence signal excited by the LED excitation light in the sample area. After the time-sharing drive scanning of the N LEDs is completed, the control and data processing module receives the fluorescence spectrum data output by the fluorescence detection device and the transmission light intensity data output by the light intensity detection device, and finally generates the three-dimensional fluorescence spectrum and absorption spectrum of the sample.

The fluorescence detection device includes a fiber optic probe and a spectrometer. A fluorescence window is opened on one side of the sample fluorescence excitation area, and the fiber optic probe is close to the fluorescence window. The spectrometer receives the synchronous trigger command sent by the control and data processing module, and measures the fluorescence signal collected by the optical fiber probe. The spectrometer is used to measure the intensity of each wavelength component in the wide-spectrum fluorescence signal, and sends the fluorescence spectrum data to the control and data processing module. The control and data processing module generates a three-dimensional fluorescence spectrum of the sample based on the wavelength of the time-sharing driven excitation light, the wavelength and intensity of the corresponding fluorescence spectrum data.

In one embodiment, alternatively, the spectrometer in the fluorescence detection device includes a filter-type multi-channel spectrometer, a micro-electromechanical system (MEMS), etc. The specific scope of protection shall be based on the claims, and this application does not make any special limitation on this.

For samples that can be penetrated by excitation light, the excitation light emitted by N LED array light sources diverges again after passing through the sample area, and the divergent excitation light is converged on the detection target surface of the light intensity detection device through the second lens group. The light intensity detection device includes a photodetector, which converts the optical signal into an electrical signal. After passing through the transimpedance amplifier (TIA), the corresponding transmitted light intensity data is obtained through analog-to-digital (AD) sampling, and the collected light intensity data is transmitted to the control and data processing module. The control and data processing module generates the absorption spectrum of the sample based on the time-sharing drive and the received transmitted light intensity information, combined with the light intensity of the monochromatic excitation light emitted by the LED.

In one embodiment, the photoelectric detection device may alternatively include a PIN photodiode, a photomultiplier tube (PMT), etc. The specific scope of protection shall be subject to the claims, and this application does not make any special limitation on this.

It should be understood that the single-wavelength excitation light emitted by each LED light source is propagated through the optical fiber, converged to the sample area through the first lens group, and the light beams of different wavelengths converge and overlap in the sample area after passing through the lens group, and the converged and overlapped area has a higher light power density; in some embodiments, the sample area is also referred to as a fluorescence excitation area, a stimulated radiation area, etc. The sample to be tested is placed in the fluorescence excitation area to be excited by the excitation light, and the light power density of the fluorescence signal emitted by the stimulated radiation is also high. Furthermore, the excitation lights of different wavelengths converge and overlap in the fluorescence excitation area, that is, the fluorescence radiation stimulated by the excitation lights of different wavelengths all originates from the same area of the same sample, which makes it easier to collect the fluorescence signal for analysis, and the analysis results are more accurate.

It should be understood that the wavelength interval of each LED is 10 to 20 nm, the wavelength interval between each LED is not necessarily the same, and the number of LED light sources set in each band from ultraviolet to near-infrared is not necessarily the same. The specific scope of protection should be based on the claims, and this application does not make any special limitations on this.

It should be understood that the fluorescent window setting position described in FIG. 3 is only for illustration and does not constitute any limitation on the protection scope of the present application.

It should be understood that in some embodiments, the sample is also referred to as a sample to be tested, a sample, a sample to be tested, a substance to be tested, etc., which is only a reference to the name and does not constitute any limitation on the scope of protection of the present application.

In one embodiment, alternatively, since LED is a surface light source with a large radiation divergence, the excitation light emitted by the LED needs to be coupled into an optical fiber for propagation. The optical fiber coupling method is used to improve the beam quality of the excitation light so as to efficiently excite the sample for fluorescence. The LED light source and the optical fiber can be coupled through a coupling module or directly coupled through a large core diameter optical fiber. Specifically, several different LED light source coupling methods will be described in conjunction with Figures 3, 4, and 5.

FIG4 is a schematic diagram of a light source coupling method in a three-dimensional fluorescence detection device provided in an embodiment of the present application. FIG4 adopts a method of using a lens as a coupling module to couple the excitation light emitted by the LED chip into the optical fiber; the lens coupling method is suitable for larger LED chips and smaller core diameter optical fibers. For example, as a non-limiting embodiment, a chip with a chip diameter (or side length) of 1 mm, a core diameter of the optical fiber of 400 um, a radiation power of the LED of 10 mW, and coupling through a specially optically designed coupling lens. Experimental measurements show that the coupling efficiency of this method can reach about 4%. The greater the radiation power of the LED, the higher the light extraction efficiency of the optical fiber; at the same time, the smaller the diameter of the LED chip and the larger the core diameter of the optical fiber, the higher the light extraction efficiency of the optical fiber coupling.

FIG5 is a schematic diagram of another light source coupling method in a three-dimensional fluorescence detection device provided in an embodiment of the present application. FIG5 adopts a method of using a large core diameter optical fiber directly as a coupling module for coupling; the direct coupling method is suitable for smaller LED chips and larger core diameter optical fibers. For example, as a non-limiting embodiment, a chip with a chip diameter (or side length) of 500um, a core diameter of the optical fiber of 500um, a radiation power of the LED of 10mW, and an incident end face of the optical fiber 100um away from the LED chip. The coupling efficiency of this direct coupling method is about 2% as measured by experiments. The greater the radiation power of the LED, the higher the light extraction efficiency of the optical fiber; at the same time, the smaller the diameter of the LED chip and the larger the core diameter of the optical fiber, the higher the light extraction efficiency of the optical fiber coupling.

It should be understood that in specific embodiments, coupling through coupling lenses and direct coupling are applicable to different scenarios. Lens coupling has lower requirements on the size of LED chips and the size of optical fiber core diameter, and the coupled light extraction efficiency is higher. However, lens coupling increases the complexity of the optical path and increases the difficulty of production. With the development of existing monochromatic light source technology, the existing LED chip light output power is still relatively high at about 50mW even near 250nm in the deep ultraviolet band. In some embodiments, direct optical fiber coupling can be used for coupling to ensure that the optical fiber coupling light output power reaches 500uW or more, so as to realize the detection of three-dimensional fluorescence spectrum and absorption spectrum; further The next step is to use direct coupling to simplify the optical path and reduce the difficulty of instrument manufacturing, thereby further reducing the production cost of the instrument and increasing the usage scenarios.

It should be understood that the cross-section of the combined multi-core optical fiber formed by the close arrangement of the optical fiber before entering the first lens group is shown in Figures 4 and 5. The close arrangement of the combined multi-core optical fiber is to minimize the area of the cross-section and facilitate the optical design after the optical path. As a non-limiting embodiment, 20-30 LED monochromatic light sources are used as array light sources in this application, and the cross-sectional diameter of the formed multi-core optical fiber is about 3 mm. The cross-section in the drawings of this application is only a schematic diagram of a possible implementation method and does not constitute any limitation on the scope of protection of this application.

6 is a schematic diagram of the structure of a lens group in a three-dimensional fluorescence detection device provided in an embodiment of the present application. The excitation light emitted by the array light source through the multi-core optical fiber is converged to the sample area through the first lens group, and the excitation light transmitted from the sample area is converged to the target surface of the photodetector through the second lens group. Among them, the sample area, that is, the fluorescence excitation area, that is, the area where the N excitation light beams of the first lens group converge and overlap, should be as small as possible to ensure that the fluorescence excitation area has sufficient excitation light power density. The excitation light will diverge rapidly after passing through the sample area, and the divergent N beams of excitation light will converge again through the second lens group. Similarly, the spot diameter formed in the area where the excitation light converges after passing through the second lens group should also be as small as possible, and the spot diameter formed should be smaller than the diameter of the detector target surface. The lens group in the drawings of the present application is only a schematic diagram of a possible implementation method and does not constitute any limitation on the scope of protection of the present application.

As a non-limiting example, in the present application, the spot formed by the excitation light after passing through the first lens group in the fluorescence excitation area is about 2 mm, and the spot formed by reaching the target surface of the photodetector after passing through the second lens group is about 3 mm. It should be understood that the diameter of the target surface area of the photosensitive area of the photodetector used in the present application is greater than 3 mm.

The sample to be tested is placed in the fluorescence excitation area, and the excited fluorescence signal radiates within the 4π solid angle of the entire space. The fluorescence probe can only receive part of the fluorescence signal. The main factors affecting the fluorescence probe receiving efficiency include the area of the core diameter end face of the optical fiber probe, the numerical aperture NA, and the distance between the end face of the optical fiber probe and the fluorescence excitation area.

As a non-limiting embodiment, in the present application, N excitation lights emitted by the array light source converge in the fluorescence excitation area, and the diameter of the light beam formed by the convergence in the overlap area is about 2 mm. When the NA of the optical fiber probe is 0.22, in order to ensure that the cone solid angle received by the optical fiber probe covers the entire fluorescence excitation area, the distance d between the probe and the fluorescence excitation area needs to satisfy:
2×d×NA＝2mm (1)

From formula (1), it can be calculated that d = 4.55 mm. Therefore, in actual design, the distance of the optical fiber probe can be selected to be slightly larger than the above theoretical distance, that is, the distance between the optical fiber probe and the fluorescence excitation area can be set to 5 mm to ensure that the receiving range of the optical fiber probe can cover the fluorescence excitation area.

FIG7 is a schematic diagram of the structure of a spectrometer in a three-dimensional fluorescence detection device provided in an embodiment of the present application. The spectrometer receives the fluorescence signal detected by the optical fiber probe from the optical fiber probe interface, and receives the synchronous trigger instruction issued by the control and data processing module from the trigger port. The spectrometer is used to detect and analyze the wavelength composition of the detected fluorescence signal and the fluorescence intensity corresponding to each wavelength. The fluorescence signal diverges from the optical fiber output end of the optical fiber probe and enters the spectrometer, that is, the fluorescence signal diverges from the optical fiber probe interface and is incident on the M1 spherical reflector of the spectrometer. The M1 spherical reflector collimates the divergent fluorescence signal, and the collimated fluorescence signal is incident on the grating. The grating disperses the wide-spectrum fluorescence signal and then incidents on the M2 spherical reflector. Since the fluorescence signals of specific wavelengths incident on the M2 spherical reflector are parallel to each other, the fluorescence signals of different wavelengths are focused on the focal plane by the M2 spherical reflector and separated from each other in space. By setting the detector on the focal plane of the M2 spherical reflector and receiving focused fluorescence signals of different wavelengths, the composition of the light signals of each wavelength in the wide-spectrum fluorescence signal and the light intensity corresponding to the light signals of each wavelength can be measured to obtain the spectrum of the fluorescence signal.

In one embodiment, alternatively, the detection device includes a linear array photoelectric detector, a planar array photoelectric detector, etc. The specific scope of protection shall be based on the claims, and this application does not make any special limitation on this.

6 and 7, one end of the optical fiber probe is used to obtain the fluorescence signal in the fluorescence excitation area, and the other end is used to input the obtained fluorescence signal into the spectrometer through the optical fiber probe interface of the spectrometer. The spectrometer performs wavelength component analysis on the received fluorescence signal and the light intensity of the fluorescence signal corresponding to each wavelength.

In one embodiment, the optical fiber probe may include a single-core fluorescent optical fiber probe, a multi-core fluorescent optical fiber probe, etc. The specific protection scope shall be subject to the claims, and this application does not make any special limitation on this. The following will explain the structures of two possible fluorescent probes in conjunction with Figures 8 and 9.

FIG8 is a schematic diagram of the structure of an optical fiber probe in a three-dimensional fluorescence detection device provided in an embodiment of the present application. A single-core fluorescent optical fiber probe is used in FIG8. When a single-core optical fiber is used as a fluorescent optical fiber probe, a single-core optical fiber with a large core diameter needs to be selected. One end of the single-core optical fiber with a large core diameter is used to obtain the fluorescence signal of the fluorescence excitation area (receiving end), and the other end is connected to the optical fiber probe interface of the spectrometer (output end) to transmit the collected fluorescence signal to the spectrometer. As a non-limiting embodiment, in the present application, the diameter of the large-core single-core optical fiber used is 1 mm, and it is directly connected to the probe interface of the spectrometer through the output end of the optical fiber (1 mm aperture).

In one embodiment, optionally, since the probe interface of the spectrometer includes various shapes such as a circle and a slit, in order to ensure the propagation of light The efficiency can be improved by combining the shape of the probe interface of the spectrometer with the output end of the optical fiber to perform optical design to ensure the signal quality of the fluorescent signal received by the spectrometer and the light output efficiency of the fluorescent probe input into the spectrometer. The specific scope of protection shall be subject to the claims, and this application does not make any special limitation on this.

FIG9 is a schematic diagram of the structure of an optical fiber probe in another three-dimensional fluorescence detection device provided in an embodiment of the present application. FIG9 uses a multi-core fluorescent optical fiber probe. When a multi-core optical fiber is used as a fluorescent optical fiber probe, a single-core optical fiber with a small core diameter needs to be selected. By closely arranging m single-core optical fibers with a small core diameter, a bundled multi-core optical fiber is formed. The receiving end of the multi-core optical fiber needs to closely arrange m single-core optical fibers with a small core diameter to form a circular end face, that is, the receiving end is located in the fluorescence excitation region for receiving the fluorescence signal generated by stimulated radiation; in order to ensure the receiving efficiency of the fluorescence signal, it is necessary to select a suitable small-core single-core optical fiber and a suitable optical fiber bundle m, so that the diameter of the circular receiving end face formed by close arrangement is in the order of several millimeters. As a non-limiting embodiment, in the present application, the diameter of the small-core single-core optical fiber used is 50um, and the diameter of the end face of the receiving end formed by close arrangement is about 3mm. The optical fiber probe interface of the spectrometer used in this embodiment is an input slit, so the output end of the multi-core optical fiber in this embodiment is arranged linearly according to the slit.

In one embodiment, optionally, since the probe interface of the spectrometer includes various shapes such as circular and slit, in order to ensure the propagation efficiency of light, the output end of the multi-core optical fiber can be arranged according to the shape of the input interface of the spectrometer, or the optical design can be combined with the shape of the probe interface of the spectrometer at the output end of the optical fiber to ensure the signal quality of the fluorescent signal received by the spectrometer and the light output efficiency of the fluorescent probe input into the spectrometer. The specific protection scope shall be subject to the claims, and this application does not make any special restrictions on this.

In the present application, the time-sharing drive of the array light source is realized by sending a time-sharing pulse drive signal by the control and data processing module, and the LED array light source is driven in time-sharing to emit a single-wavelength excitation light, and the fluorescence detection device and the light intensity detection device synchronously receive the detected fluorescence signal and the transmitted light signal in time-sharing, thereby generating fluorescence spectrum data and transmitted light intensity data, and the control and data processing module processes the data according to the correspondence between the fluorescence spectrum data and the transmitted light intensity data and the excitation light wavelength, thereby obtaining the three-dimensional fluorescence spectrum and absorption spectrum of the sample. The following will describe the drive signal sent by the control and data processing module and the data processing process in conjunction with Figures 10 to 12.

FIG10 is a schematic diagram of an array light source drive signal in a three-dimensional fluorescence detection device provided in an embodiment of the present application. The control and data processing module sends an LED time-sharing pulse drive signal to the LED array light source, and the drive signal drives the constant current source to provide current pulse drive to LED1, LED2, LED3, etc. in a time-sharing manner. As a non-limiting embodiment, the current pulse signal of each LED in the present application is driven by a square wave, and the duration of the pulse is 500ms, that is, each LED light source is illuminated for 500ms in a time-sharing manner under the action of the pulse signal, and the fluorescence signal generated by the stimulated radiation of the sample in the fluorescence excitation area can also be approximately regarded as a square wave pulse fluorescence signal lasting 500ms.

When the control and data processing module sends a time-sharing pulse drive signal to the array light source, it also synchronously sends a synchronous trigger signal to the trigger interface of the spectrometer. After receiving the synchronous trigger signal, the spectrometer starts the detector in the spectrometer to start measuring. The measured integration time is used as a reference to obtain a good fluorescence signal-to-noise ratio, and can be set to an appropriate integration time window that is less than the duration of the excitation light pulse. As a non-limiting embodiment, the integration time window in this application can be set in the range of 400ms-480ms according to the detected fluorescence signal-to-noise ratio, and the specific value can be set according to the measured fluorescence signal-to-noise ratio as a reference.

When the control and data processing module sends the LED time-sharing pulse drive signal to the array light source, that is, the control and data processing module drives each LED light source to emit excitation light in turn with a 500ms pulse current, the spectrometer also synchronously measures each LED, that is, the fluorescence spectrum corresponding to each wavelength of excitation light. As a non-limiting embodiment, the present application uses surface water as a sample, and detects surface water to obtain a three-dimensional fluorescence spectrum and absorption spectrum of the surface water. The following is an explanation of sample detection to obtain a three-dimensional fluorescence spectrum and absorption spectrum in conjunction with Figures 11 to 12.

FIG11 is a three-dimensional fluorescence spectrum generated by detecting a sample using a three-dimensional fluorescence detection device provided in an embodiment of the present application. The figure includes fluorescence spectra excited by excitation light of 250nm, 260nm...400nm. It should be understood that each wavelength of excitation light corresponds to an LED light source. Each fluorescence spectrum in the figure is a two-dimensional spectrum line, the horizontal axis is the wavelength of the fluorescence signal, and the vertical axis is the light intensity of the fluorescence signal. The Gaussian shape part protruding in the front of each fluorescence spectrum line in the figure is the Rayleigh scattering of the excitation light, and the tailing part behind the Rayleigh scattering is the fluorescence signal of the sample. In order to output the three-dimensional fluorescence spectrum of the sample, the control and data processing module will automatically deduct the Rayleigh scattering component in front of each fluorescence spectrum line, and then use the compensation algorithm to calculate the front edge of the fluorescence spectrum, and then use the wavelength of the array light source excitation light as the X-axis, the wavelength of the fluorescence signal as the Y-axis, and the light intensity of the fluorescence signal as the Z-axis to generate the three-dimensional fluorescence spectrum of the sample, as shown in the embedded figure in the upper right corner of FIG11, which is the three-dimensional fluorescence spectrum of surface water.

As a non-limiting embodiment, the compensation algorithm used in this application includes an interpolation algorithm. Other compensation algorithms can also be used according to the characteristics of the sampled data, which are not listed here. The specific protection scope shall be subject to the claims, and this application does not make any special restrictions on this.

For transmissive samples, the present application can also simultaneously obtain the absorption spectrum of the sample, such as the surface water mentioned above. It should be understood that the detection samples of the present application can include transmissive samples and non-transmissive samples, and valuable absorption spectra can be generated synchronously for transmissive samples; for non-transmissive samples, it means that the excitation light beam is completely absorbed and/or reflected by the non-transmissive sample, and the absorption spectrum obtained is meaningless.

FIG12 is an absorption spectrum generated by detecting a sample using a three-dimensional fluorescence detection device provided in an embodiment of the present application. The excitation light emitted by the LED array light source penetrates the sample area and reaches the absorption target surface of the light intensity detection device, that is, the PIN target surface of the photodetector in the embodiment of the present application. After the photodetector receives the pulse square wave light signal of 500ms emitted by each LED light source, it passes through the TIA amplification circuit and AD analog-to-digital conversion to a digital signal and transmits it to the control and data processing module. The control and data processing module averages the received transmission light intensity data within the set time integration window to obtain the transmitted light intensity value. As a non-limiting embodiment, in order to obtain the absorption spectrum of the sample in the present application, it is necessary to scan the LED array light source without a sample to obtain the initial light intensity value I ₀ of the excitation light emitted by each light source, and then place the sample to be tested in the sample area, scan the LED array light source again, and obtain the light intensity value I ₁ of the transmitted light after penetrating the sample. According to the Beer-Lambert law, the formula for calculating the sample absorbance is:

Wherein, abs represents the absorbance of the sample. The absorption spectrum of the sample can be determined according to the measured initial light intensity value I ₀ and the transmitted light intensity value I ₁ by formula (2). The absorption spectrum of the surface water sample in this application is shown in FIG12 , where the abscissa is the wavelength of the excitation light emitted by the array light source, and the ordinate corresponds to the absorbance abs value of the excitation light of each wavelength.

It should be understood that since the wavelength interval of the excitation light emitted by each LED in the array light source is 10nm to 20nm, the absorption spectrum measured by the above method is drawn by discrete points with an interval of 10nm to 20nm, and the resolution of the absorption spectrum is determined by the wavelength interval of each single-wavelength light source in the array light source. For most mixture samples, the absorption spectrum of the sample presents a wide spectrum and smooth characteristics. The absorption spectrum data composed of N discrete points obtained in this application is interpolated and smoothed to obtain a continuous absorption spectrum curve that is consistent with the absorption spectrum obtained by a high-precision laboratory absorption spectrum measurement device under the same conditions.

It should be noted that FIGS. 1 to 12 are merely schematic illustrations for facilitating understanding of the embodiments of the present application and do not constitute any particular limitation on the present application.

The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (13)

A three-dimensional fluorescence detection device, characterized in that it comprises: a monochromatic array light source, a first lens group, a fluorescence detection device, a light intensity detection device, and a control and data processing module, wherein: The monochromatic array light source is used to emit excitation light, and the monochromatic array light source includes N monochromatic light sources, and the monochromatic light source is used to emit light with a single wavelength, and the excitation light includes light of N wavelengths and covers a first band, wherein N is a positive integer greater than or equal to 2, and the first band has an intersection with a fluorescence excitation band of a sample to be tested; The first lens group is used to receive the excitation light and converge and overlap the excitation light to form an excitation area, wherein N beams of the excitation light are incident on the first lens group at different positions, and the sample to be tested is placed in the excitation area; The fluorescence detection device is used to receive the fluorescence signal generated by the sample to be tested and output fluorescence spectrum data. The light intensity detection device is used to receive the excitation light transmitted from the sample to be tested and output the transmitted light intensity data; The control and data processing module is used to control the monochromatic array light source to emit the excitation light, and is also used to receive the fluorescence spectrum data and the transmitted light intensity data to determine the three-dimensional fluorescence spectrum and absorption spectrum of the sample to be tested. The three-dimensional fluorescence detection device according to claim 1 is characterized in that the N wavelengths of light emitted by the N monochromatic light sources are sequentially spaced apart by a first wavelength interval, comprising: When N is greater than or equal to 3, the nth monochromatic light source emits light having a first wavelength, the n+1th monochromatic light source emits light having a second wavelength, and the n+2th monochromatic light source emits light having a third wavelength, and n, n+1, and n+2 are positive integers belonging to N; The first wavelength and the second wavelength differ by a first value, the second wavelength and the third wavelength differ by a second value, and the first wavelength interval includes the first value and the second value. The three-dimensional fluorescence detection device according to claim 1 or 2 is characterized in that the lights emitted by the N monochromatic light sources are directly coupled through N optical fibers respectively, and the N optical fibers transmit the excitation light emitted by the monochromatic array light source to the first lens group, and the output ends of the N optical fibers are arranged nonlinearly. The three-dimensional fluorescence detection device according to claim 1 or 2 is characterized in that the light emitted by the N monochromatic light sources is coupled into N optical fibers through N coupling lenses respectively, and the N optical fibers transmit the excitation light emitted by the monochromatic array light source to the first lens group, and the output ends of the N optical fibers are arranged nonlinearly. The three-dimensional fluorescence detection device according to claim 3 or 4 is characterized in that the nonlinear arrangement includes a closely arranged arrangement, and the closely arranged arrangement includes that the surface area of the output end cross-section formed by the arrangement of the N optical fibers is the smallest, and the output end cross-section includes a circle. The three-dimensional fluorescence detection device according to any one of claims 1 to 5, characterized in that it also includes: The second lens group is used to converge the excitation light transmitted from the sample to be tested to the receiving target surface of the light intensity detection device, and the diameter of the light spot formed by the convergence of the excitation light is less than or equal to the diameter of the photosensitive area of the receiving target surface. The three-dimensional fluorescence detection device according to any one of claims 1 to 6, characterized in that the control and data processing module is used to control the monochromatic array light source to emit the excitation light, comprising: The control and data processing module sends a driving signal to the monochromatic array light source, wherein the driving signal includes a square wave pulse signal, and the driving signal is used to sequentially drive N monochromatic light sources to emit light in sequence, and the light emission duration of the monochromatic light source is the pulse duration of the square wave pulse signal. The three-dimensional fluorescence detection device according to claim 7 is characterized in that the control and data processing module is also used to send a synchronization trigger instruction to the fluorescence detection device to start the fluorescence detection device to sequentially receive the pulse fluorescence signals generated by the excitation area. The three-dimensional fluorescence detection device according to any one of claims 1 to 8, characterized in that the fluorescence detection device comprises an optical fiber probe and a spectrometer, The optical fiber probe is used to obtain the fluorescence signal generated by the excitation region. The spectrometer is used to obtain the composition of the fluorescence bands in the fluorescence signal and the light intensity of the fluorescence in each band. The three-dimensional fluorescence detection device according to claim 9, characterized in that the optical fiber probe comprises a single-core fluorescent optical fiber probe, The input end of the single-core fluorescent optical fiber probe directly detects the fluorescent signal generated by the excitation region. The output end of the single-core fluorescent optical fiber probe is directly connected to the optical fiber probe interface of the spectrometer. The three-dimensional fluorescence detection device according to claim 9, characterized in that the optical fiber probe comprises a multi-core fluorescent optical fiber probe, The multi-core fluorescent optical fiber probe comprises three or more single-core optical fibers, and the single-core optical fibers are arranged in a closely spaced manner. The rows are arranged to form the input end of the multi-core fluorescent probe, and the input end is used to detect the fluorescent signal generated by the excitation area; The single-core optical fiber is arranged in a linear manner to form the output end of the multi-core fluorescent probe, and the output end is connected to the optical fiber probe interface of the spectrometer. The three-dimensional fluorescence detection device according to any one of claims 9 to 11, characterized in that the detection distance between the input end of the optical fiber probe and the excitation region includes:
2×d×NA＝D Wherein, d is the detection distance, NA is the numerical aperture of the optical fiber probe, and D is the diameter of the light spot formed by the excitation light converging in the excitation region. The three-dimensional fluorescence detection device according to any one of claims 1 to 12, characterized in that the light intensity detection device comprises a photodetector and an amplifying circuit, The photodetector is used to receive the excitation light transmitted from the sample to be tested, and convert the received light signal into an electrical signal; The amplifier circuit is used to amplify the electrical signal.