CN101825629A - Waveguide coupling metal photonic crystal biosensor and detecting method thereof - Google Patents

Abstract

The invention relates to a waveguide coupling metal photonic crystal biosensor and a detection method thereof, which are used for high-sensitivity sensing of the concentration of biomolecules and the specific reaction of bioactive molecules. The invention includes a substrate, a waveguide layer and a metal photonic crystal prepared on the waveguide layer. When detecting, the light emitted by the light source is irradiated on the metal photonic crystal at a certain angle, and the light detector detects the extinction spectrum of the transmitted light passing through the waveguide layer and the substrate. , or detect the extinction spectrum of the reflected light passing through the metal photonic crystal, then fix the receptor on the metal photonic crystal and then flow the sample solution through the surface of the metal photonic crystal, and then use the detector to detect the light passing through the waveguide layer and The extinction spectrum of the transmitted light of the substrate, or the extinction spectrum of the reflected light passing through the metal photonic crystal, is calculated for the second extinction spectrum to realize the quantitative detection of the ligand concentration. The invention has the advantages of high sensitivity, low cost, simple preparation and use methods and the like.

Description

Waveguide coupled metal photonic crystal biosensor and its detection method

technical field

The invention is a waveguide-coupled metal photonic crystal biosensor and its detection method, which is based on the physical mechanism of the strong spectroscopic coupling between the particle plasmon resonance in the metal photonic crystal and the waveguide resonance mode, which can be used for biomolecules (proteins) , sugar molecules, DNA, etc.) and the high-sensitivity sensing of the specific reaction of biologically active molecules, which belong to the cross field of optoelectronic technology and biotechnology.

Background technique

Biomolecular sensors with high sensitivity and high resolution characteristics play a very important role in scientific research and practical applications such as biology, life science, and medicine. Biosensors based on spectral response characteristics show unique advantages due to their reliable physical principles and sophisticated technical means.

The basic structure of a traditional surface plasmon resonance (SPR) biosensor is shown in Figure 1. The sensor is composed of a transparent substrate 1 , a metal layer 2 deposited on the upper surface of the substrate 1 , a prism 6 , a light source 7 and a light detector 8 . The working principle of the SPR biosensor for biospecific reaction sensing is as follows: the beam from the broadband light source 7 is incident on the prism 6 at a certain angle, and the prism 6 guides the incident light into the transparent substrate at a large angle, and the incident light that is introduced is in the metal Total reflection occurs at the interface between the layer 2 and the substrate 1 to excite an evanescent wave in the metal layer 2 . In the case of a given incident angle, a certain frequency in the evanescent wave will be consistent with the surface plasmon resonance frequency of the metal layer 2, so that the incident light is strongly resonantly absorbed at this frequency, and the frequency at this frequency is measured in its reflection spectrum a prominent absorption peak. This is the so-called surface plasmon resonance absorption. In practical applications, a monochromatic light source (such as a laser) can also be used as the incident light, and the purpose of plasmon resonance absorption of the metal layer on its surface can be realized by changing the incident angle. Most of the technologies currently used are the former, that is, using a fixed incident angle and a broadband light source, which can avoid problems such as cumbersome operation, large errors, and system instability caused by angle adjustment.

In the biosensing experiment, firstly, the receptor 4, which can specifically recognize the ligand 3, is fixed on the metal layer 2. Since the surface plasmon resonance frequency strongly depends on the dielectric constant (refractive index) of the environment, the The metal thin film with receptor molecules immobilized has a specific SPR frequency. Then the receptor fixed on the metal film 2 interacts with the ligand 3 in the sample solution 5, and the receptor and the ligand react specifically, and the dielectric constant at the surface of the metal layer changes, thereby causing the metal layer The surface plasmon resonance frequency shifted. Thus, the ligand concentration information in the sample solution can be obtained.

Biosensors based on SPR technology still have the disadvantages of complex device structure, high preparation technology requirements, cumbersome system operation, long test cycle, and high cost. Therefore, biosensors with simple structure, high sensitivity, fast testing process, and low cost have become an urgent requirement and important research and development content in biomedicine and other fields.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned defects of existing biosensors, and propose a waveguide-coupled metal photonic crystal biosensor and its detection method. The biosensor has the advantages of high sensitivity, low cost, and simple preparation and use methods.

The physical mechanism based on the biosensor in the present invention is: the strong coupling between the waveguide resonance mode (WGM) and the particle plasmon resonance (PPR) mode of the metal photonic crystal, so it is called "waveguide coupling metal photonic crystal biosensor" .

The technical scheme adopted by the present invention is as follows: the biosensor comprises a substrate 21, a transparent waveguide layer 22 covering the substrate 21, and a metal photonic crystal 23 covering the waveguide layer 22 from bottom to top.

The thickness of the waveguide layer 21 is 60nm-300nm.

The metal photonic crystal 23 is a one-dimensional metal photonic crystal or a two-dimensional metal photonic crystal.

The period of the one-dimensional metal photonic crystal is 150nm-550nm.

The period of the two directions of the two-dimensional metal photonic crystal can be the same or different, and the value range is 150nm-550nm.

Using the above-mentioned waveguide-coupled metal photonic crystal biosensor for detection, the detection method is as follows:

1) After immobilizing the receptor 4 having a specific recognition function for the ligand 3 on the metal photonic crystal 23, contact the blank sample solution with the surface of the metal photonic crystal 23;

2) After passing through the polarization controller 31, the light emitted by the light source 7 irradiates the metal photonic crystal at an angle θ with the normal line of the plane where the substrate 21 is located (the range of θ is 0-80°), and the photodetector 8 detects the light passing through the blank sample solution , the extinction spectrum of the transmitted light of the metal photonic crystal 23, the waveguide layer 22 and the substrate 21;

3) The sample solution containing the ligand flows over the surface of the metal photonic crystal 23, and the ligand reacts specifically with the receptor. After using the blank sample solution in step 1) to wash away unreacted ligands, then contact the blank sample solution with the surface of the metal photonic crystal 23;

4) After passing through the polarization controller 31, the light emitted by the light source 7 irradiates the metal photonic crystal with the normal line of the plane where the substrate 21 is located at the same θ angle as step 2), and the photodetector 8 detects the metal photonic crystal through the blank sample solution and the metal photonic crystal. , the extinction spectrum of the transmitted light of the waveguide layer 22 and the substrate 21;

5) The extinction spectrum in step 2) and step 4) is used as the secondary extinction spectrum calculation, and the quantitative detection of the ligand concentration is realized by characterizing the spectroscopic variation law of different ligand concentrations.

Using the above-mentioned waveguide-coupled metal photonic crystal biosensor for detection can also be carried out as follows:

1) After immobilizing the receptor 4 having a specific recognition function for the ligand 3 on the metal photonic crystal 23, contact the blank sample solution with the surface of the metal photonic crystal 23;

2) The light emitted by the light source 7 passes through the polarization controller 31 and irradiates the substrate at an angle θ with the normal of the plane where the substrate 21 is located (the range of θ is 0° to 80°). The extinction spectrum of the transmitted light of metal photonic crystal 23 and blank sample solution;

3) The sample solution containing the ligand flows over the surface of the metal photonic crystal 23, and the ligand reacts specifically with the receptor. Use the blank sample solution in step 1) to wash away unreacted ligands, and finally contact the blank sample solution with the surface of the metal photonic crystal 23;

4) The light emitted by the light source 7 passes through the polarization controller 31 and irradiates the substrate at the same angle θ as the normal line of the plane where the substrate 21 is located, and the photodetector 8 detects the substrate 21, the waveguide layer 22, and the metal photonic crystal The extinction spectrum of the transmitted light after the reaction with the blank sample solution;

5) The extinction spectrum in step 2) and step 4) is used as the secondary extinction spectrum calculation, and the quantitative detection of the ligand concentration is realized by characterizing the spectroscopic variation law of different ligand concentrations.

Using the above-mentioned waveguide-coupled metal photonic crystal biosensor for detection can also be carried out as follows:

1) After immobilizing the receptor 4 having a specific recognition function for the ligand 3 on the metal photonic crystal 23, contact the blank sample solution with the surface of the metal photonic crystal 23;

2) The light emitted by the light source 7 passes through the polarization controller 31 and forms an angle θ with the normal line of the plane where the substrate 21 is located (the range of θ is 0-80°) to irradiate the metal photonic crystal, and the photodetector 8 detects and passes through the blank sample solution in sequence , the extinction spectrum of the reflected light emitted back by the substrate 21 after the metal photonic crystal and the waveguide layer 22;

3) The sample solution containing the ligand flows over the surface of the metal photonic crystal 23, and the ligand reacts specifically with the receptor. Use the blank sample solution in step 1) to wash away unreacted ligands, and finally bring the blank sample solution into contact with the surface of the metal photonic crystal 23 again.

4) After passing through the polarization controller 31, the light emitted by the light source 7 irradiates the metal photonic crystal at the same θ angle as that of step 2) with the normal line of the plane where the substrate 21 is located. After the photodetector 8 detects the reaction, it passes through the blank sample solution, metal The extinction spectrum of the reflected light reflected by the substrate 21 after the photonic crystal 23 and the waveguide layer 22;

5) The extinction spectrum in step 2) and step 4) is used as the secondary extinction spectrum calculation, and the quantitative detection of the ligand concentration is realized by characterizing the spectroscopic variation law of different ligand concentrations.

Using the above-mentioned waveguide-coupled metal photonic crystal biosensor for detection can also be carried out as follows:

1) After immobilizing the receptor 4 having a specific recognition function for the ligand 3 on the metal photonic crystal 23, contact the blank sample solution with the surface of the metal photonic crystal 23;

2) The light emitted by the light source 7 passes through the polarization controller 31 and irradiates the substrate 21 at an angle θ with the normal of the plane where the substrate 21 is located (the range of θ is 0° to 80°), and the photodetector 8 detects the light passing through the substrate 21 and the waveguide layer in turn. The extinction spectrum of the reflected light reflected by the metal photonic crystal after 22;

3) The sample solution containing the ligand flows over the surface of the metal photonic crystal 23, and the ligand reacts specifically with the receptor. Use the blank sample solution in step 1) to wash away unreacted ligands, and finally contact the blank sample solution with the surface of the metal photonic crystal 23 .

4) After passing through the polarization controller 31, the light emitted by the light source 7 irradiates the substrate 21 at the same angle θ with the normal of the plane where the substrate 21 is located as in step 2), and the photodetector 8 detects the reaction and passes through the substrate 21 and the waveguide layer 22 in sequence , the extinction spectrum of the reflected light reflected by the metal photonic crystal;

5) The extinction spectrum in step 2) and step 4) is used as the secondary extinction spectrum calculation, and the quantitative detection of the ligand concentration is realized by characterizing the spectroscopic variation law of different ligand concentrations.

The device in the present invention can also be used to quantitatively detect changes in the concentration of substances, specifically the following detection methods:

One, use the waveguide coupling metal photonic crystal biosensor among the present invention to carry out the detection of substance concentration, can carry out according to the following method:

1) contacting the blank sample solution with the surface of the metal photonic crystal 23;

2) The light emitted by the light source 7 passes through the polarization controller 31 and irradiates the metal photonic crystal at an angle θ with the normal line of the plane where the substrate 21 is located (the range of θ is 0 to 80°). The extinction spectrum of the transmitted light of the metal photonic crystal 23, the waveguide layer 22 and the substrate 21;

3) Flow a sample solution containing a certain substance over the surface of the metal photonic crystal 23 and make contact with the surface of the metal photonic crystal 23 .

4) After passing through the polarization controller 31, the light emitted by the light source 7 irradiates the metal photonic crystal at the same θ angle as that of step 2) with the normal line of the plane where the substrate 21 is located, and the photodetector 8 detects the metal photonic crystal through the sample solution, the metal photonic crystal 23, The extinction spectrum of the transmitted light of the waveguide layer 22 and the substrate 21;

5) The extinction spectrum in step 2) and step 4) is used as the secondary extinction spectrum calculation, and the quantitative detection of the concentration of the substance is realized by characterizing the spectroscopic variation law of different concentrations of the substance.

2. The difference between this method and method 1 is that the detection light is incident from the substrate, and the specific steps are as follows:

1) contacting the blank sample solution with the surface of the metal photonic crystal 23;

2) After passing through the polarization controller 31 , the light emitted by the light source 7 irradiates the substrate 21 at an angle θ with the normal to the plane where the substrate 21 is located (the range of θ is 0° to 80°), and the photodetector 8 detects the light passing through the substrate 21 and the waveguide layer 22 , the extinction spectrum of the transmitted light of metal photonic crystal 23 and blank sample solution;

3) Flow a sample solution containing a certain substance over the surface of the metal photonic crystal 23 and make contact with the surface of the metal photonic crystal 23 .

4) The light emitted by the light source 7 passes through the polarization controller 31 and irradiates the substrate 21 at the same angle θ with the normal line of the plane where the substrate 21 is located as in step 2). 23 and the extinction spectrum of the transmitted light of the sample solution;

5) The extinction spectrum in step 2) and step 4) is used as the secondary extinction spectrum calculation, and the quantitative detection of the concentration of the substance is realized by characterizing the spectroscopic variation law of different concentrations of the substance.

Three, the method for detecting reflected light that this method adopts determines the change of substance concentration, and its specific steps are as follows:

1) contacting the blank sample solution with the surface of the metal photonic crystal 23;

2) The light emitted by the light source 7 passes through the polarization controller 31 and forms an angle θ with the normal line of the plane where the substrate 21 is located (the range of θ is 0-80°) to irradiate the metal photonic crystal, and the photodetector 8 detects and passes through the blank sample solution in sequence , behind the metal photonic crystal 23 and the waveguide layer 22, the extinction spectrum of the reflected light reflected by the substrate 21;

3) Flow a sample solution containing a certain substance over the surface of the metal photonic crystal 23 and make contact with the surface of the metal photonic crystal 23 .

4) After passing through the polarization controller 31, the light emitted by the light source 7 irradiates the metal photonic crystal at the same θ angle as that of step 2) with the normal line of the plane where the substrate 21 is located, and the photodetector 8 detects and passes through the sample solution, the metal photonic crystal and the metal photonic crystal successively. After the waveguide layer 22, the extinction spectrum of the reflected light reflected by the substrate 21;

5) The extinction spectrum in step 2) and step 4) is used as the secondary extinction spectrum calculation, and the quantitative detection of the concentration of the substance is realized by characterizing the spectroscopic variation law of different concentrations of the substance.

4. The difference between this method and method 3 is that the detection light is incident from the substrate, and the specific steps are as follows:

1) contacting the blank sample solution with the surface of the metal photonic crystal 23;

2) The light emitted by the light source 7 passes through the polarization controller 31 and irradiates the substrate 21 at an angle θ with the normal line of the plane where the substrate 21 is located (the range of θ is 0° to 80°), and the light detector 8 detects the light passing through the substrate 21 and the waveguide layer 22 The extinction spectrum of the reflected light reflected by the metal photonic crystal;

3) Flow the sample solution containing a certain substance through the surface of the metal photonic crystal 23, and contact with the surface of the metal photonic crystal 23;

4) The light emitted by the light source 7 passes through the polarization controller 31 and irradiates the substrate 21 at the same angle θ with the normal of the plane where the substrate 21 is located as in step 2). The extinction spectrum of the reflected light reflected by the photonic crystal;

5) The extinction spectrum in step 2) and step 4) is used as the secondary extinction spectrum calculation, and the quantitative detection of the concentration of the substance is realized by characterizing the spectroscopic variation law of different concentrations of the substance.

The working principle of the biosensor is shown in Figure 5: the incident light 24 excites the particle plasmon resonance in the metal photonic crystal 23 and is strongly absorbed in the characteristic spectral region, and is diffracted by the metal photonic crystal and excited in the waveguide layer 22 Waveguide Propagation Mode 27. The waveguide mode is diffracted by the metal photonic crystal on the upper surface during propagation to generate multiple beams of diffracted light 28 parallel to the transmitted light 26 , and the diffracted light 28 further interferes with the transmitted light 26 . In this way, a narrow-band transmission-enhanced signal can be observed in the measured broadband plasmon resonance absorption spectrum of the transmitted light, which is the result of the coupling between the waveguide mode and the plasmon resonance mode. Both the particle plasmon resonance absorption and the spectral response characteristics of the waveguide resonance mode of the metal photonic crystal shift with the change of the environmental refractive index on the upper surface of the metal photonic crystal, and the shift amount directly corresponds to the change of the environmental refractive index. Therefore, the variation of the ambient refractive index can be quantitatively characterized by measuring the variation of the particle plasmon resonance absorption and the coupling spectrum of the waveguide resonance mode. This is the working principle of the biosensor in the present invention. The introduction of the narrowband waveguide resonance mode greatly improves the sensitivity of the sensor response.

The detection principle of the waveguide-coupled metal photonic crystal biosensor of the present invention is as follows: in the biospecific reaction sensing experiment, at first the receptor (antibody) 4 with specific recognition function to the ligand (antigen) 3 is fixed on the metal photonic crystal The surface of 23 constitutes the initial diaphragm of the sensor; the sample solution 5 flows through the surface of the metal photonic crystal 23, if there is a ligand (antigen) 3 in the sample, the receptor (antibody) 4 and the ligand (antigen) 3 A specific reaction will occur. According to the change of the extinction spectrum before and after the reaction, the small change in the coupling effect between the waveguide mode and the particle plasmon resonance mode is quantitatively given. Through the quantitative characterization of the change law of the spectrum, the ligand in the sample solution 5 Detection of the concentration of (antigen) 3. In the substance concentration detection experiment, the sample solution 5 flows through the surface of the metal photonic crystal 23. If the concentration of the substance to be tested in the sample changes, according to the change of the extinction spectrum before and after the concentration change, the waveguide mode and particle plasmon resonance can be quantitatively given. The small change in the coupling effect between the modes realizes the detection of the concentration of the substance to be measured through the quantitative characterization of the change law of the spectrum.

The advantages and characteristics of the present invention which are different from traditional SPR sensors are reflected in the following aspects:

1) Low cost: The cost of both the waveguide-coupled metal photonic crystal sensor device and the spectroscopy test system is much lower than that of the SPR sensor system. The cost of the whole sensor system is only less than 10% of the price of the existing SPR biosensors on the market. Its core waveguide-coupled metal photonic crystal sensor can be reused, which improves the flexibility of practical applications.

2) High sensitivity: the introduction of the waveguide resonance mode realizes the narrow-band modulation of the particle plasmon resonance mode, which greatly improves the sensitivity of the device to the change of the refractive index of the environment.

3) The test method is flexible and simple: according to different needs, a variety of test methods are available; during the test process, only conventional optical and spectroscopic test methods are used to obtain the transmission or reflection spectrum or the transmission or reflection extinction spectrum.

4) Ease of integration: waveguide-coupled metal photonic crystals are small in size and regular in shape, making them easy to embed into a system to form a biochip structure.

Description of drawings

Figure 1 Schematic diagram of the traditional surface plasmon resonance biosensor structure

Fig. 2 is a cross-sectional view of the waveguide coupling metal photonic crystal biosensor of the present invention

Figure 3 is the front view of the waveguide coupling one-dimensional metal photonic crystal biosensor of the present invention

Figure 4 is the front view of the waveguide coupling two-dimensional metal photonic crystal biosensor of the present invention

Fig. 5 is the optical principle diagram of the waveguide coupling metal photonic crystal biosensor of the present invention

Fig. 6 is a structural diagram of the waveguide coupling metal photonic crystal biosensor of the present invention

Fig. 7 is a schematic diagram of the front transmissive detection of the biosensor of the present invention

Figure 8 is a schematic diagram of the backside transmission detection of the biosensor of the present invention

Figure 9 is a schematic diagram of the front reflective detection of the biosensor of the present invention

Figure 10 is a schematic diagram of the back reflective detection of the biosensor of the present invention

Fig. 11 The extinction spectrum of the transmissive waveguide coupling gold photonic crystal biosensor in the present invention

Fig. 12 The detection signal of the transmissive waveguide coupling gold photonic crystal biosensor in the present invention

Figure 13 The extinction spectrum of the reflected light of the reflective waveguide coupling gold photonic crystal biosensor in the present invention

Figure 14 The detection signal of the reflective waveguide coupling gold photonic crystal biosensor in the present invention

In the figure: 1. Transparent substrate, 2. Metal layer, 3. Ligand (antigen), 4. Receptor (antibody), 5. Sample solution, 6. Prism, 7. Light source, 8. Photodetector, 21 . Substrate, 22. Waveguide layer, 23. Metal photonic crystal, 31. Polarization controller.

Detailed ways

The present invention will be further described below with reference to accompanying drawing:

The biosensor in the present invention comprises a substrate 21 (thickness is D), a transparent waveguide layer 22 (thickness d) covered on the substrate 21 and a metal photonic crystal 23 (period is Λ) covered on the waveguide layer 22, the biological The cross-sectional view of the sensor is shown in Figure 2. Wherein: the thickness d of the waveguide layer 22 ranges from 60 to 300 nm, and the metal photonic crystal 23 can adopt a one-dimensional ( FIG. 3 ) or two-dimensional structure ( FIG. 4 ), which is called a one-dimensional or two-dimensional metal photonic crystal. The period of the one-dimensional metal photonic crystal is 150-550 nm, and the period of the two-dimensional photonic crystal in both directions can be 150-550 nm.

In the biosensor of the present invention, a metal (preferably gold, silver or platinum) one-dimensional or two-dimensional photonic crystal is prepared on the transparent waveguide layer 22 of the substrate 21, and a waveguide-coupled metal photonic crystal biosensor as shown in FIGS. 2 to 4 is obtained. ;

The detection method of the waveguide coupling metal photonic crystal biosensor in the present invention is as follows:

1) In the biospecific recognition detection, first, the receptor (antibody) 4 that has a specific recognition function for the ligand (antigen) 3 is immobilized on the metal photonic crystal in the waveguide-coupled metal photonic crystal biosensor prepared in step 1) The surface of 23 constitutes the initial diaphragm of the sensor;

2) Spectral testing methods can be used as shown in Figure 7 to Figure 10:

3) Flow the sample solution 5 over the surface of the biosensor obtained in step 3), if there is a ligand (antigen) 3 in the sample, the receptor (antibody) 4 will specifically react with it, according to the extinction spectrum before and after the reaction Changes, quantitatively give the small changes in the coupling between the waveguide mode and the particle plasmon resonance mode (as shown in Figure 11 or Figure 13), and by characterizing the changes in spectroscopy of different concentrations of antigens, the ligands in the sample solution 5 ( Quantitative detection of antigen)3 concentration.

The detection of the waveguide coupling metal photonic crystal biosensor in the present invention can also adopt the following method:

1) contacting a blank sample solution (solvent) with the surface of the metal photonic crystal 23;

2) Spectral testing methods can be used as shown in Figure 7 to Figure 10;

3) Contact the sample solution containing a certain substance (the solution of the substance to be measured) with the surface of the metal photonic crystal 23, and quantitatively give the tiny coupling effect between the waveguide mode and the particle plasmon resonance mode according to the change of the concentration of the sample solution. Change (as shown in Figure 11 or Figure 13), by characterizing the spectroscopic variation law of different concentrations of the substance, the quantitative detection of the concentration of the substance is realized;

Below is the example of device among the present invention and detection method thereof:

Example 1:

This embodiment is a front transmissive waveguide coupling one-dimensional metal photonic crystal biosensor and its detection method:

The substrate 21 used in this embodiment is made of glass with thickness D=1mm, and the waveguide layer 22 is made of indium tin oxide (ITO) thin film glass sheet with thickness d=200nm.

In this embodiment, a one-dimensional gold photonic crystal with a period of Λ=330nm is prepared on the ITO waveguide layer of a glass substrate by a preparation method of interference lithography combined with a solution method, and a waveguide-coupled one-dimensional gold photonic crystal biosensor is obtained. When using this sensor for detection, the detection method is as follows:

1) A receptor (antibody) 4 with a specific recognition function for the ligand (antigen) 3 is immobilized on the surface of the metal photonic crystal 23 in the waveguide-coupled one-dimensional metal photonic crystal biosensor to form the initial diaphragm of the sensor, and the The blank sample solution (buffer solution or solvent not containing the substance to be tested) is in contact with the surface of the metal photonic crystal 23;

2) The spectrum test method adopts the front transmission type as shown in Figure 7, the light source is selected from a bromine tungsten lamp, and the incident light passes through the polarization controller 31 to form an angle of θ=32° with the normal of the plane where the substrate 21 is located. The waveguide is coupled with the one-dimensional metal photonic crystal to irradiate light, and the photodetector 8 detects the extinction spectrum of the transmitted light passing through the blank sample solution, the one-dimensional metal photonic crystal, the waveguide layer and the substrate;

3) Flow the sample solution containing the ligand (antigen) 3 (buffer solution or solvent containing the substance to be tested) through the surface of the biosensor obtained in step 2), the ligand (antigen) 3 and the receptor (antibody) 4 When a specific recognition reaction occurs, use the blank sample solution in step 2) to wash away the unreacted antigens, and finally contact the blank sample solution with the surface of the metal photonic crystal 23;

4) After the light emitted by the bromine tungsten lamp light source passes through the polarization controller 31, it irradiates the one-dimensional metal photonic crystal at an angle of θ=32° with the normal of the plane where the substrate 21 is located, and the photodetector detects the one-dimensional metal photonic crystal through the blank sample solution, one-dimensional Extinction spectrum of transmitted light after reaction of metal photonic crystal, waveguide layer and substrate;

5) Step 2) is compared with the extinction spectrum in step 4), and the slight change in the coupling effect between the waveguide mode and the particle plasmon resonance mode before and after the reaction is obtained as shown in Figure 11, and the extinction spectrum is processed twice to obtain the extinction spectrum as shown in Figure 11. The signal shown in 12 realizes the quantitative detection of the antigen concentration by characterizing the spectroscopic change rule of different antigen concentrations.

Example 2:

This embodiment is a back transmission type two-dimensional waveguide coupling metal photonic crystal biosensor and its detection method:

The substrate used in this embodiment is glass with a thickness of D=1mm, and the waveguide layer is made of ITO glass sheet with a thickness of d=200nm.

In this example, two-dimensional gold photonic crystals with Λ=350nm period in both directions were prepared on the ITO waveguide layer of the glass substrate by the preparation method of interference lithography combined with the solution method, and a waveguide-coupled two-dimensional gold photonic crystal biosensor was obtained. When using this sensor for detection, the detection method is as follows:

1) Immobilize the receptor (antibody) 4 that has a specific recognition function for the ligand (antigen) 3 on the surface of the metal photonic crystal in the two-dimensional waveguide-coupled metal photonic crystal biosensor to form the initial diaphragm of the sensor. The material solution is in contact with the surface of the metal photonic crystal;

2) The spectrum test method adopts the back (substrate surface) transmission type as shown in Figure 8, the light source is a bromine tungsten lamp, and the incident light passes through the polarization controller at an angle of θ=48° to the normal of the plane where the substrate 21 is located. In the embodiment, the substrate of the waveguide-coupled two-dimensional metal photonic crystal biosensor is illuminated, and the photodetector detects the extinction spectrum of the transmitted light passing through the substrate, the waveguide layer, the two-dimensional metal photonic crystal and the blank sample solution;

3) Flow the antigen-containing sample solution over the surface of the biosensor obtained in step 2), and the antigen and the antibody have a specific recognition reaction, use the blank sample solution in step 2) to wash away the unreacted antigen, and finally the blank The sample solution is in contact with the surface of the metal photonic crystal 23 .

4) After the light emitted by the bromine tungsten lamp light source passes through the polarization controller, it irradiates the substrate at an angle of θ=48° with the normal of the plane where the substrate 21 is located, and the photodetector detects that the incident light passes through the substrate, the waveguide layer, and the two-dimensional metal photonic crystal and the extinction spectrum of the transmitted light of the blank sample solution;

5) Step 2) is compared with the extinction spectrum in step 4), and the slight change in the coupling effect between the waveguide mode and the particle plasmon resonance mode as shown in Figure 11 is obtained, and the extinction spectrum is processed twice to obtain the extinction spectrum as shown in Figure 12 Quantitative detection of antigen concentration can be realized by characterizing the spectroscopic change rule of different antigen concentration.

Example 3:

This embodiment is a front reflective waveguide coupling one-dimensional metal photonic crystal biosensor and its detection method:

The substrate used in this embodiment is glass with a thickness of D = 1 mm, and the waveguide layer is an ITO glass sheet with a thickness of d = 210 nm.

In this embodiment, a one-dimensional gold photonic crystal with a period of Λ=400nm is prepared on an ITO waveguide of a glass substrate by a preparation method of interference lithography combined with a solution method, and a waveguide-coupled one-dimensional gold photonic crystal biosensor is obtained;

1) Immobilize the antibody with specific recognition function on the antigen on the surface of the metal photonic crystal in the waveguide-coupled one-dimensional metal photonic crystal biosensor to form the initial diaphragm of the sensor, and contact the blank sample solution with the surface of the metal photonic crystal 23 ;

2) The spectrum test method adopts the front reflection type as shown in Figure 9, and the light source is a bromine tungsten lamp. After the incident light passes through the polarization controller, it forms an angle of θ=2° with the normal of the plane where the substrate 21 is located. The one-dimensional metal photonic crystal surface of the waveguide-coupled one-dimensional metal photonic crystal biosensor is irradiated, and the irradiation light is reflected by the substrate 21 after sequentially passing through the blank sample solution, the one-dimensional metal photonic crystal, and the waveguide layer, and the photodetector 8 receives the reflected light. Extinction spectrum;

3) Flow the antigen-containing sample solution over the surface of the biosensor obtained in step 2), and the antigen and the antibody have a specific recognition reaction, use the blank sample solution in step 2) to wash away the unreacted antigen, and finally the blank The sample solution is in contact with the surface of the metal photonic crystal 23 .

4) After the light emitted by the bromine tungsten lamp light source passes through the polarization controller, it irradiates the one-dimensional metal photonic crystal at an angle of θ=2° with the normal of the plane where the substrate 21 is located, and the photodetector detects the one-dimensional metal photonic crystal after passing through the blank sample solution and the one-dimensional metal photonic crystal. After the photonic crystal and the waveguide layer, the extinction spectrum of the reflected light after the reaction reflected by the substrate;

5) Step 2) is compared with the extinction spectrum in step 4), and the slight change in the coupling between the waveguide mode and the particle plasmon resonance mode before and after the reaction is obtained as shown in Figure 13, and the extinction spectrum is processed twice to obtain the extinction spectrum as shown in Figure 13. The signal shown in 14 realizes the quantitative detection of the antigen concentration by characterizing the spectroscopic change rule of different antigen concentrations.

Example 4:

This embodiment is a back reflective one-dimensional waveguide coupling metal photonic crystal biosensor and its detection method: the device in this embodiment is the same as that of Embodiment 3, and its detection method is basically the same as that of Embodiment 3, the only difference being: incident The light is incident on the substrate 21 after passing through the polarization controller, and the detector 8 detects the extinction spectrum of the light reflected by the metal photonic crystal after the incident light passes through the substrate, the waveguide layer and the metal photonic crystal.

The sensor in the present invention can also realize the detection of the concentration of substances, which will be described below in conjunction with specific detection methods:

Example 5:

This embodiment is a front transmission two-dimensional waveguide coupling metal photonic crystal biosensor and its detection method:

The substrate used in this embodiment is glass with a thickness of D=1mm, and the waveguide layer is made of ITO glass sheet with a thickness of d=200nm.

In this example, two-dimensional gold photonic crystals with periods of Λ=350nm in both directions were prepared on the ITO waveguide layer of the glass substrate by the preparation method of interference lithography combined with the solution method, and a waveguide-coupled two-dimensional gold photonic crystal biosensor was obtained. Using the device in this embodiment to detect the substance concentration, the steps of its detection are as follows:

1) contacting a blank sample (pure water) with the surface of the two-dimensional metal photonic crystal 23;

2) The light emitted by the light source 7 passes through the polarization controller 31 and irradiates the metal photonic crystal at an angle of 36° to the normal of the plane where the substrate 21 is located. The photodetector 8 detects that it passes through the pure water, the metal photonic crystal 23 waveguide layer 22, and the substrate in sequence. The extinction spectrum of the transmitted light of 21;

3) Flow the sample solution containing sucrose (aqueous solution of sucrose) through the surface of the metal photonic crystal 23, and contact with the surface of the metal photonic crystal 23;

4) The light emitted by the light source 7 passes through the polarization controller 31 and irradiates the metal photonic crystal at an angle of 36° to the normal of the plane where the substrate 21 is located. The extinction spectrum of the transmitted light of the substrate 21;

5) Calculate the extinction spectrum in step 2) and step 4) as the second extinction spectrum, and obtain the signal generated by the change of sucrose concentration as shown in Figure 14, and realize the detection of sucrose by characterizing the spectral change law of different concentrations of sucrose. Quantitative detection of concentration.

Embodiment 6:

This embodiment is a backside transmission type one-dimensional waveguide coupling metal photonic crystal biosensor and its detection method: the device in this embodiment is the same as that of Embodiment 5, and its detection method is basically the same as that of Embodiment 5, the only difference being: incident The light is incident on the substrate 21 after passing through the polarization controller, and the light detector 8 detects the extinction spectrum of the transmitted light after the incident light passes through the substrate, the waveguide layer and the metal photonic crystal.

Embodiment 7:

This embodiment is a front reflective one-dimensional waveguide coupling metal photonic crystal biosensor and its detection method: the device in this embodiment is the same as that of Embodiment 5, and its detection method is basically the same as that of Embodiment 5, except that the incident After the light passes through the polarization controller, it is incident on the metal photonic crystal 23 . The detector 8 detects the extinction spectrum of the reflected light reflected by the substrate 21 after the incident light passes through the metal photonic crystal, waveguide layer and substrate.

Embodiment 8:

This embodiment is a back reflective one-dimensional waveguide coupling metal photonic crystal biosensor and its detection method: the device in this embodiment is the same as that of Embodiment 5, and its detection method is basically the same as that of Embodiment 5, the only difference being: incident The light is incident on the substrate 21 after passing through the polarization controller, and the light detector 8 detects the extinction spectrum of the reflected light reflected by the metal photonic crystal 21 after the incident light passes through the substrate, the waveguide layer, and the metal photonic crystal in sequence.

Claims (10)

1. Waveguide coupling metal photonic crystal biosensor is characterized in that: comprise substrate from top to bottom successively, cover suprabasil transparent ducting layer and cover metal photonic crystal on the ducting layer.

2. Waveguide coupling metal photonic crystal biosensor according to claim 1 is characterized in that: the thickness of described ducting layer is 60nm～300nm.

3. Waveguide coupling metal photonic crystal biosensor according to claim 1 is characterized in that: described metal photonic crystal is one-dimensional metal photon crystals or two-dimensional metallic photonic crystal.

4. according to claim 1 or the described Waveguide coupling metal photonic crystal biosensor of claim 3, it is characterized in that: the cycle of described one-dimensional metal photon crystals is 150nm～550nm; The cycle of described two-dimensional metallic photonic crystal both direction can be the same or different, and is 150nm～550nm.

5. the method for using the described Waveguide coupling metal photonic crystal biosensor of claim 1 to detect is characterized in that this method may further comprise the steps:

1) after fixing the acceptor that part is had the specific recognition function on the metal photonic crystal, blank sample solution is contacted with the surface of metal photonic crystal;

2) become 0～80 ° of angle to be radiated on the metal photonic crystal with the normal with plane, substrate place behind the light process Polarization Controller that light source sends, photodetector detects the extinction spectra through the transmitted light of blank sample solution, metal photonic crystal, ducting layer and substrate;

3) sample solution that will the contain part surface of metal photonic crystal of flowing through, part and acceptor generation specific reaction; After utilizing blank sample solution in the step 1) to wash the part that does not react, more blank sample solution is contacted with the surface of metal photonic crystal;

4) light that sends of light source through behind the Polarization Controller to become and step 2 with the normal on plane, substrate place) identical angular illumination metal photonic crystal, photodetector detects the extinction spectra through the transmitted light of blank sample solution, metal photonic crystal, ducting layer and substrate;

5) with step 2) do the calculating of secondary extinction spectrum with the extinction spectra in the step 4), by characterizing the spectroscopy Changing Pattern of different ligands concentration, realize detection by quantitative to part.

6. the method for using the described Waveguide coupling metal photonic crystal biosensor of claim 1 to detect is characterized in that this method may further comprise the steps:

1) after fixing the acceptor that part is had the specific recognition function on the metal photonic crystal, blank sample solution is contacted with the surface of metal photonic crystal;

2) become 0～80 ° of angle irradiation substrate with the normal on plane, substrate place behind the light process Polarization Controller that light source sends, photodetector detects the extinction spectra through the transmitted light of substrate, ducting layer, metal photonic crystal and blank sample solution;

3) sample solution that will the contain part surface of metal photonic crystal of flowing through, part and acceptor generation specific reaction, utilize the blank sample solution of step 1) to wash the part that does not react, at last blank sample solution is contacted with the surface of metal photonic crystal again;

4) become and step 2 with the normal on plane, substrate place behind the light process Polarization Controller that light source sends) identical angular illumination substrate, photodetector detects the extinction spectra through the reacted transmitted light of substrate, ducting layer, metal photonic crystal and blank sample solution;

5) with step 2) do the calculating of secondary extinction spectrum with the extinction spectra in the step 4), by characterizing the spectroscopy Changing Pattern of different ligands concentration, realize detection by quantitative to ligand concentration.

7. the method for using the described Waveguide coupling metal photonic crystal biosensor of claim 1 to detect is characterized in that this method may further comprise the steps:

1) after fixing the acceptor that part is had the specific recognition function on the metal photonic crystal, blank sample solution is contacted with the surface of metal photonic crystal;

2) become 0～80 ° of angle irradiation metal photonic crystal with the normal on plane, substrate place behind the light process Polarization Controller that light source sends, photodetector detects the catoptrical extinction spectra through being fired back by substrate behind blank sample solution, metal photonic crystal and the ducting layer successively;

3) sample solution that will the contain part surface of metal photonic crystal of flowing through, part and acceptor generation specific reaction, utilize the blank sample solution of step 1) to wash the part that does not react, at last blank sample solution is contacted with the surface of metal photonic crystal again;

4) light that sends of light source is through becoming and step 2 with the normal on plane, substrate place behind the Polarization Controller) identical angular illumination metal photonic crystal, the catoptrical extinction spectra through being reflected by substrate behind blank sample solution, metal photonic crystal and the ducting layer successively after the photodetector detection reaction;

5) with step 2) do the calculating of secondary extinction spectrum with the extinction spectra in the step 4), by characterizing the spectroscopy Changing Pattern of different ligands concentration, realize detection by quantitative to ligand concentration.

8. the method for using the described Waveguide coupling metal photonic crystal biosensor of claim 1 to detect is characterized in that this method may further comprise the steps:

1) after fixing the acceptor that part is had the specific recognition function on the metal photonic crystal, blank sample solution is contacted with the surface of metal photonic crystal;

2) become 0～80 ° of angle irradiation substrate with the normal on plane, substrate place behind the light process Polarization Controller that light source sends, photodetector detects the catoptrical extinction spectra through being reflected by metal photonic crystal behind substrate and the ducting layer successively;

3) sample solution that will the contain part surface of metal photonic crystal of flowing through, part and acceptor generation specific reaction, utilize the blank sample solution of step 1) to wash the part that does not react, at last blank sample solution is contacted with the surface of metal photonic crystal;

4) become and step 2 with the normal on plane, substrate place behind the light process Polarization Controller that light source sends) identical angular illumination substrate, after passing through substrate and ducting layer successively after the photodetector detection reaction, the catoptrical extinction spectra that is reflected by metal photonic crystal;

5) with step 2) do the calculating of secondary extinction spectrum with the extinction spectra in the step 4), by characterizing the spectroscopy Changing Pattern of different ligands concentration, realize detection by quantitative to ligand concentration.

9. the method for using the described Waveguide coupling metal photonic crystal biosensor of claim 1 to detect is characterized in that this method may further comprise the steps:

1) blank sample solution is contacted with the surface of metal photonic crystal;

2) become 0～80 ° of angle to shine metal photonic crystal with the normal on plane, substrate place behind the light process Polarization Controller that light source sends, photodetector detects the extinction spectra of the transmitted light that passes through blank sample solution, metal photonic crystal, ducting layer and substrate successively, perhaps shine metal photonic crystal, photodetector detects the extinction spectra of the transmitted light that passes through blank sample solution, metal photonic crystal, ducting layer and substrate successively;

3) sample solution that will contain certain material surface of metal photonic crystal of flowing through, and contact with the surface of metal photonic crystal;

4) become and step 2 with the normal on plane, substrate place behind the light process Polarization Controller that light source sends) identical angular illumination metal photonic crystal, photodetector detects the extinction spectra of the transmitted light that passes through sample solution, metal photonic crystal, ducting layer and substrate successively, perhaps shine substrate, photodetector detects the extinction spectra of the transmitted light that passes through substrate, ducting layer, metal photonic crystal and blank sample solution successively;

5) with step 2) do the calculating of secondary extinction spectrum with the extinction spectra in the step 4), by characterizing the spectroscopy Changing Pattern of this material variable concentrations, realize detection by quantitative to this material concentration.

10. the method for using the described Waveguide coupling metal photonic crystal biosensor of claim 1 to detect is characterized in that this method may further comprise the steps:

1) blank sample solution is contacted with the surface of metal photonic crystal;

2) become 0～80 ° of angle to shine metal photonic crystal with the normal on plane, substrate place behind the light process Polarization Controller that light source sends, photodetector detects through behind blank sample solution, metal photonic crystal and the ducting layer, the catoptrical extinction spectra that is reflected by substrate, perhaps shine substrate, after photodetector detects and to pass through substrate, ducting layer successively, the catoptrical extinction spectra that is reflected by metal photonic crystal;

3) sample solution that will contain certain material surface of metal photonic crystal of flowing through, and contact with the surface of metal photonic crystal;

4) become and step 2 with the normal on plane, substrate place behind the light process Polarization Controller that light source sends) identical angular illumination metal photonic crystal, photodetector detects through behind blank sample solution, metal photonic crystal and the ducting layer, the catoptrical extinction spectra that is reflected by substrate, perhaps shine substrate, after photodetector detects and to pass through substrate, ducting layer successively, the catoptrical extinction spectra that is reflected by metal photonic crystal;

5) with step 2) do the calculating of secondary extinction spectrum with the extinction spectra in the step 4), by characterizing the spectroscopy Changing Pattern of this material variable concentrations, realize detection by quantitative to this material concentration.

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