CN108204965A - A kind of micro-fluidic light quantum substance finger print target of NERS-SERS substrates - Google Patents

Abstract

The present invention provides a kind of micro-fluidic light quantum substance finger print targets of NERS SERS substrates.Its structure includes micro-channel unit and temperature gradient controller；Temperature gradient controller includes two micro temperature sensors, a semiconductor chilling plate and a Miniature heating plate；Micro-channel unit includes metal nanoparticle colloidal sol memory, recover and level Four fluid channel.Gap enhancing Raman scattering is equipped in third level fluid channel to be combined with Surface enhanced Raman scattering（NERS‑SERS）Substrate, NERS SERS substrates are made of sinusoidal pattern silver grating and metal nanoparticle colloidal sol；The setting of semiconductor chilling plate and Miniature heating plate can ensure to generate temperature gradient at micro-channel unit both ends.The present invention have many advantages, such as light, high integration, high sensitivity, can continuously detect, the feature of environmental protection it is good, particularly suitable for portable, the repeatable type, kind and its " Raman fingerprint " for identifying the explosives such as trace ammunition present in air.

Description

A NERS-SERS Substrate Microfluidic Optical Quantum Matter Fingerprint Target

technical field

The invention relates to the technical fields of optical quantum Surface Enhanced Raman Scattering (SERS) spectrum detection, microfluidic substance detection and trace explosive detection, in particular to a NERS-SERS substrate microfluidic optical quantum substance fingerprint target.

Background technique

In the current surface-enhanced Raman scattering (Surface Enhanced Raman Scattering, SERS) microfluidic detection technology, there are two main types of Raman-enhanced substrates widely used: one is a single metal nanoparticle sol, including gold nanoparticle sol and silver nanoparticle sol. Particle sol; the other is nano-array structure, including hemispherical nano-array structure, columnar nano-array structure, etc. The SERS enhancement factor of a single metal nanoparticle sol can generally reach 10 ⁸ . In order to improve the detection sensitivity, the SERS enhancement factor needs to be improved. The Raman-enhanced substrate of the nano-array structure has the disadvantage that continuous detection cannot be realized. The reason is that the detection molecules are easily adsorbed on the nano-array structure. make an impact.

Contents of the invention

The purpose of the present invention is to provide a NERS-SERS substrate microfluidic photoquantum substance fingerprint target to solve the problems that the existing microfluidic SERS detection cannot be continuously sampled and detected and the detection sensitivity is low.

The object of the present invention is achieved in this way: a NERS-SERS substrate microfluidic optical quantum substance fingerprint target, including a microfluidic unit and a temperature gradient controller for controlling the temperature gradient at both ends of the microfluidic unit;

The microchannel unit includes a metal nanoparticle sol storage, a first-stage microchannel, a second-stage microchannel, a third-stage microchannel, a fourth-stage microchannel and a metal nanoparticle sol recoverer; The metal nanoparticle sol storage is used to store the metal nanoparticle sol, and the metal nanoparticle sol recycler is used to recover the metal nanoparticle sol; the first-stage microchannel, the second-stage microchannel, the The third-level micro-channel and the fourth-level micro-channel are sequentially connected, and the metal nano-particle sol in the metal nano-particle sol storage can pass through the first-level micro-channel, the second The first-level micro-channel, the third-level micro-channel and the fourth-level micro-channel enter the metal nanoparticle sol recoverer; the upper surface of the metal nanoparticle sol recoverer is an open structure;

The second-level micro-channels include at least three capillary micro-channels, and the upper surface of each capillary micro-channel is a completely open structure; the second-level micro-channels are used to make the micro-channels in the micro-channel unit The metal nanoparticle sol absorbs the trace substances to be detected in the concentrated air;

The third-level micro-channel is a micro-channel integrated with a SERS enhanced detection area; a small hole for laser incident and detection signal collection is arranged on the upper surface of the third-level micro-channel; A periodic sinusoidal silver grating is integrated on the lower surface of the microchannel, and the sinusoidal silver grating and the metal nanoparticle sol flowing on it together constitute the NERS-SERS substrate;

The temperature gradient controller includes a first miniature temperature sensor, a second miniature temperature sensor, a miniature heating chip and a semiconductor cooling chip;

The first miniature temperature sensor is located below the metal nanoparticle sol recoverer, and is used to detect the temperature around the metal nanoparticle sol recoverer; the second miniature temperature sensor is located at the metal nanoparticle sol storage Below, for detecting the temperature around the metal nanoparticle sol storage;

The miniature heating sheet is located below the first miniature temperature sensor for increasing the temperature around the metal nanoparticle sol recovery device; the semiconductor refrigeration sheet is located below the second miniature temperature sensor for Lower the temperature around the metal nanoparticle sol reservoir.

The sinusoidal silver grating is processed by laser interference photolithography and physical vapor deposition. The period of the sinusoidal silver grating is 400nm-1000nm, the sinusoidal amplitude is 10nm-100nm, and the thickness of the silver layer of the grating is 50nm-200nm.

The shape of the metal nanoparticle sol flowing in the microchannel unit is spherical, and the diameter of the spherical particles is 50nm-200nm.

Both the metal nanoparticle sol storage and the metal nanoparticle sol collector are cuboid container structures; the metal nanoparticle sol storage has a length of 1000 μm to 5000 μm, a width of 1000 μm to 5000 μm, and a depth of 50 μm to 200 μm; The metal nanoparticle sol recoverer has a length of 1000 μm to 5000 μm, a width of 1000 μm to 5000 μm, and a depth of 50 μm to 200 μm.

Both the first-stage micro-channel and the fourth-stage micro-channel are elongated channel structures with a rectangular or circular cross-section; the length of the first-stage micro-channel is 1 mm to 5 mm, The width is 100 μm-500 μm, and the depth is 50 μm-200 μm; the length of the fourth-stage micro-channel is 1 mm-5 mm, the width is 100 μm-500 μm, and the depth is 50 μm-200 μm.

Each capillary microchannel in the second-stage microchannel has a width of 10 μm to 30 μm, a length of 1 mm to 5 mm, and a depth of 5 μm to 20 μm.

The third-level micro-channel is an elongated channel structure; the length of the third-level micro-channel is 0.2 mm to 2 mm, the width is 100 μm to 500 μm, and the depth is 5 μm to 20 μm.

The first miniature temperature sensor is 2mm-5mm away from the lower bottom of the metal nanoparticle sol recoverer; the micro heating plate is 5mm-15mm away from the lower bottom of the metal nanoparticle sol recoverer.

The second miniature temperature sensor is 2 mm to 5 mm away from the lower bottom of the metal nanoparticle sol storage; the semiconductor refrigeration chip is 5 mm to 15 mm away from the lower bottom of the metal nanoparticle sol storage.

The microfluidic channel unit in the present invention is the internal structure of the bionic canine nasal cavity, and the present invention can continuously detect whether the air contains explosives such as trace ammunition, and has high detection sensitivity. By controlling the temperature gradient at both ends of the microchannel unit and adjusting the flow velocity of the metal nanoparticle sol in the microchannel unit, it is ensured that the dimer in the microchannel in the third-level integrated SERS enhanced detection area has a higher concentration, thereby realizing NERS -The role of the SERS substrate to further improve the sensitivity of SERS detection. By controlling the temperature gradient at both ends of the microfluidic channel unit, the bionic plant transpiration is used to realize the continuous renewal flow of the metal nanoparticle sol in the microfluidic channel unit, which solves the problem that the current microfluidic SERS detection technology cannot continuously sample and quickly detect. Therefore, the present invention has the advantages of high integration, high sensitivity, continuous sampling and the like.

The periodical sinusoidal silver grating in the NERS-SERS substrate in the present invention is not easy to absorb detection molecules, and can be detected again without cleaning, and at the same time, the temperature gradient controller in the present invention is used to control the continuous flow of the metal nanoparticle sol in the microchannel unit. Flow, so as to achieve continuous detection. The invention organically combines the microfluidic technology and the NERS-SERS detection technology, integrates the characteristics and advantages of the two, and realizes high-sensitivity and continuous on-line detection of trace explosive gas.

Description of drawings

Fig. 1 is a structural schematic diagram of an optical quantum substance fingerprint target of NERS-SERS substrate microfluidics in the present invention, wherein "1" means the "microfluidic unit" in the present invention indicated in the dotted box.

Fig. 2 is a structural schematic diagram of the second-stage microchannel and the third-stage microchannel of the microchannel unit in the present invention.

Fig. 3 is a schematic structural view of the NERS-SERS substrate on the inner and lower surface of the third-stage microchannel in the present invention.

Fig. 4 is a schematic diagram of the distribution of electromagnetic field intensity between ordinary single gold nanoparticle sols.

Fig. 5 is a schematic diagram of the electromagnetic field intensity distribution between gold nanoparticle sols in the NERS-SERS substrate of the present invention.

Fig. 6 is a schematic diagram of the concentration distribution of the metal nanoparticle sol dimer in the four-stage microfluidic channel in the present invention.

In the figure: 1. Microchannel unit, 2. Metal nanoparticle sol storage, 3. Metal nanoparticle sol loading channel, 4. First stage microchannel, 5. Second stage microchannel, 6. Third stage Microchannel, 7. Small hole for laser incidence and detection signal collection, 8. Fourth stage microchannel, 9. Metal nanoparticle sol recovery device, 10. First micro temperature sensor, 11. Micro heating plate, 12. Semiconductor Refrigerator sheet, 13, second miniature temperature sensor, 14, NERS-SERS substrate, 15, sinusoidal silver grating, 16, metal nanoparticle sol.

Detailed ways

As shown in FIG. 1 , the target of the present invention includes a microfluidic unit 1 and a temperature gradient controller. Microchannel unit 1 includes metal nanoparticle sol storage 2, first stage microchannel 4, second stage microchannel 5, third stage microchannel 6, fourth stage microchannel 8 and metal nanoparticle sol recovery Device 9. The temperature gradient controller includes a first miniature temperature sensor 10 , a second miniature temperature sensor 13 , a miniature heating chip 11 and a semiconductor cooling chip 12 .

The metal nanoparticle sol storage 2 and the metal nanoparticle sol recovery device 9 are cuboid container structures, the metal nanoparticle sol storage 2 is a closed structure, and the upper surface of the metal nanoparticle sol recovery device 9 is a completely open structure, which is convenient for transpiration generation. The metal nanoparticle sol memory 2 has a length of 1000 μm to 5000 μm, a width of 1000 μm to 5000 μm, and a depth of 50 μm to 200 μm. The metal nanoparticle sol collector 9 has a length of 1000 μm-5000 μm, a width of 1000 μm-5000 μm, and a depth of 50 μm-200 μm.

A metal nanoparticle sol loading channel 3 is provided on the upper surface of the metal nanoparticle sol storage 2. The metal nanoparticle sol loading channel 3 can be a vertical circular tube structure, for example. The metal nanoparticle sol loading channel 3 and the metal nanoparticle sol storage The inner cavity of 2 is connected, and the metal nanoparticle sol can be introduced into the metal nanoparticle sol storage 2 through the metal nanoparticle sol loading channel 3 .

The metal nanoparticle sol in the metal nanoparticle sol memory 2 can pass through the first-stage microchannel 4, the second-stage microchannel 5, the third-stage microchannel 6, and the fourth-stage microchannel 8 to enter the metal nanoparticle sol. In the nanoparticle sol recovery device 9. The first stage microchannel 4 communicates with the metal nanoparticle sol storage 2 , and the fourth stage microchannel 8 communicates with the metal nanoparticle sol recycler 9 . The first-level micro-channel 4 and the fourth-level micro-channel 8 are elongated channel structures, and their cross-sections can be rectangular or circular. The length of the first-stage micro-channel 4 is 1 mm-5 mm, the width is 100 μm-500 μm, and the depth is 50 μm-200 μm. The length of the fourth-stage micro-channel 8 is 1 mm to 5 mm, the width is 100 μm to 500 μm, and the depth is 50 μm to 200 μm.

As shown in Figure 2, the second-stage microchannel 5 is composed of at least three capillary microchannels arranged in parallel, the upper surface of each capillary microchannel is a completely open structure, and the width of each capillary microchannel is 10 μm to 30 μm , with a length of 1 mm to 5 mm and a depth of 5 μm to 20 μm. The second-stage microchannel 5 is used to make the metal nanoparticle sol in the microchannel unit 1 absorb trace substances to be detected in the concentrated air, so it is an open microchannel.

The third-level micro-channel 6 is also a long strip channel structure. The third-level micro-channel 6 is a micro-channel integrated with a SERS enhanced detection area. The length of the third-level micro-channel 6 is 0.2 mm to 2 mm, and the width It is 100 μm to 500 μm, and the depth is 5 μm to 20 μm. A small hole 7 for laser incident and detection signal collection is arranged on the upper surface of the third-stage micro-flow channel 6, and the signal emitted by the laser can be irradiated into the third-stage micro-flow channel 6 through the small hole, and the Raman spectrometer can also pass through The small hole detects the Raman signal generated by the NERS-SERS substrate 14 in the third-stage micro-channel 6 . The matching laser operating wavelength of the SERS enhanced detection region is 470nm, 532nm, 658nm or 785nm.

In conjunction with FIG. 3 , periodic sinusoidal silver gratings 15 are integrated on the lower surface of the third-stage microchannel 6 , and the sinusoidal silver gratings 15 together with the metal nanoparticle sol 16 flowing thereon constitute the NERS (Nanogap Enhanced RamanScattering )-SERS substrate 14, the NERS-SERS substrate 14 is the substrate combining gap-enhanced Raman scattering and surface-enhanced Raman scattering. The sinusoidal silver grating 15 is integrated into the lower surface of the third-level micro-channel 6 through laser interference lithography and physical vapor deposition processes. The period of the sinusoidal silver grating 15 is 400 nm-1000 nm, the sinusoidal amplitude is 10 nm-100 nm, and the thickness of the silver grating film is 50 nm-200 nm. The metal nanoparticle sol 16 flows in the entire microchannel unit 1 , which can be silver or gold nanoparticle sol, and is used to adsorb trace substance molecules in the air to be detected and form dimers. The shape of the metal nanoparticle sol 16 is spherical, and the diameter of the spherical particles is 50-200 nm.

As shown in Figure 6, Figure 6 is a schematic diagram of the distribution of the concentration of the metal nanoparticle sol dimer in the four-stage microflow channel. In the figure, the area with a small gray value represents a small concentration, and the area with a large gray value represents a relatively high concentration. It can be seen that the concentration of metal nanoparticle sol dimer gradually increases from the first-stage microchannel to the fourth-stage microchannel and has reached a larger concentration in the third-stage microchannel.

As shown in Figure 4 and Figure 5, taking the gold nanoparticle sol as an example, Figure 4 is the electromagnetic field intensity distribution between ordinary single gold nanoparticle sols, and Figure 5 is the electromagnetic field between gold nanoparticle sols in the NERS-SERS substrate In terms of intensity distribution, obviously, the electromagnetic field strength of the latter has been significantly improved compared with the former, so the detection sensitivity can be improved by the present invention.

The present invention adopts the NERS-SERS substrate, that is, the metal nanoparticle sol is combined with the periodic sinusoidal silver grating, and the surface plasmon resonance effect formed by the periodic sinusoidal silver grating and the local plasmon resonance effect formed by the metal nanoparticle sol can be coupled, The local electromagnetic field between the metal nanoparticle sols is further enhanced, and the SERS enhancement factor can reach 10 ⁹ , which is an order of magnitude higher than the prior art, thereby improving the sensitivity of SERS detection and realizing high-sensitivity detection.

The first miniature temperature sensor 10 is located below the metal nanoparticle sol recoverer 9 , and the first miniature temperature sensor 10 is 2 mm to 5 mm away from the bottom of the metal nanoparticle sol recoverer 9 . The micro-heating chip 11 is located below the first micro-temperature sensor 10 , and the distance from the micro-heating chip 11 to the lower bottom of the metal nanoparticle sol recoverer 9 is 5 mm to 15 mm. The size of the micro-heating chip 11 is on the order of millimeters, and the size of the micro-heating chip 11 in this embodiment is 8×8×3.5 mm.

The second miniature temperature sensor 13 is located below the metal nanoparticle sol storage 2 , and the second miniature temperature sensor 13 is 2 mm to 5 mm away from the bottom of the metal nanoparticle sol storage 2 . The size of the miniature temperature sensors is on the order of millimeters. In this embodiment, the dimensions of the first miniature temperature sensor 10 and the second miniature temperature sensor 13 are both 4×4×3 mm. The semiconductor cooling chip 12 is located below the second miniature temperature sensor 13 , and the semiconductor cooling chip 12 is 5 mm to 15 mm away from the bottom of the metal nanoparticle sol storage 2 .

The semiconductor cooling chip 12 is used to reduce the temperature of the area around the metal nanoparticle sol storage 2, and the micro heating chip 11 is used to increase the temperature of the area around the metal nanoparticle sol recovery device 9, and the first micro temperature sensor 10 is used to measure the metal nanoparticle sol The temperature of the area around the recoverer 9 is measured by the second miniature temperature sensor 13 to measure the temperature of the area around the metal nanoparticle sol storage 2, thereby controlling the temperature gradient at both ends of the micro-channel unit 1 . The flow velocity of the metal nanoparticle sol 16 in the microchannel unit 1 is adjusted by transpiration, and the metal nanoparticle sol 16 flows from the metal nanoparticle sol storage 2 to the metal nanoparticle sol collector 9 .

The invention provides a NERS-SERS substrate microfluidic optical quantum material fingerprint target which can be combined with a Raman spectrometer and a laser for detecting trace explosive molecules in the air. The NERS-SERS substrate microfluidic optical quantum substance fingerprint target includes a microfluidic channel unit and a temperature gradient controller; the temperature gradient controller includes two miniature temperature sensors, a semiconductor refrigeration chip and a micro heating chip; the microfluidic channel unit includes Metal nanoparticle sol storage, recycler and four-stage micro-flow channel. There is a NERS-SERS substrate in the third-level microchannel, which is composed of a periodic sinusoidal silver grating and a metal nanoparticle sol on it; A temperature gradient is generated at both ends of the channel unit, and then the required temperature gradient is controlled through the detection results of the micro-temperature sensor, so that the transpiration is used to drive the metal nanoparticle sol in the micro-channel unit to continuously update the flow. The invention has the advantages of portability, high integration, high sensitivity, continuous detection, good environmental protection, etc., and is especially suitable for portable and repeatable identification of the types and varieties of explosives such as trace ammunition in the air and their "Raman fingerprint".

Claims (10)

1. A NERS-SERS substrate microfluidic optical quantum substance fingerprint target, characterized in that it includes a microfluidic unit and a temperature gradient controller for controlling the temperature gradient at both ends of the microfluidic unit; The microchannel unit includes a metal nanoparticle sol storage, a first-stage microchannel, a second-stage microchannel, a third-stage microchannel, a fourth-stage microchannel and a metal nanoparticle sol recoverer; The metal nanoparticle sol storage is used to store the metal nanoparticle sol, and the metal nanoparticle sol recycler is used to recover the metal nanoparticle sol; the first-stage microchannel, the second-stage microchannel, the The third-level micro-channel and the fourth-level micro-channel are sequentially connected, and the metal nano-particle sol in the metal nano-particle sol storage can pass through the first-level micro-channel, the second The first-level micro-channel, the third-level micro-channel and the fourth-level micro-channel enter the metal nanoparticle sol recoverer; the upper surface of the metal nanoparticle sol recoverer is an open structure; The second-level micro-channels include at least three capillary micro-channels, and the upper surface of each capillary micro-channel is a completely open structure; the second-level micro-channels are used to make the micro-channels in the micro-channel unit The metal nanoparticle sol absorbs the trace substances to be detected in the concentrated air; The third-level micro-channel is a micro-channel integrated with a SERS enhanced detection area; a small hole for laser incident and detection signal collection is arranged on the upper surface of the third-level micro-channel; A periodic sinusoidal silver grating is integrated on the lower surface of the microchannel, and the sinusoidal silver grating and the metal nanoparticle sol flowing on it together constitute the NERS-SERS substrate; The temperature gradient controller includes a first miniature temperature sensor, a second miniature temperature sensor, a miniature heating chip and a semiconductor cooling chip; The first miniature temperature sensor is located below the metal nanoparticle sol recoverer, and is used to detect the temperature around the metal nanoparticle sol recoverer; the second miniature temperature sensor is located at the metal nanoparticle sol storage Below, for detecting the temperature around the metal nanoparticle sol storage; The miniature heating sheet is located below the first miniature temperature sensor for increasing the temperature around the metal nanoparticle sol recovery device; the semiconductor refrigeration sheet is located below the second miniature temperature sensor for Lower the temperature around the metal nanoparticle sol reservoir. 2. The NERS-SERS substrate microfluidic optical quantum substance fingerprint target according to claim 1, wherein the sinusoidal silver grating is processed by laser interference lithography and physical vapor deposition. 3. The NERS-SERS substrate microfluidic optical quantum substance fingerprint target according to claim 1, wherein the period of the sinusoidal silver grating is 400nm～1000nm, the sinusoidal amplitude is 10nm～100nm, and the thickness of the silver layer of the grating is 50nm to 200nm. 4. NERS-SERS substrate microfluidic light quantum material fingerprint target according to claim 1, is characterized in that, the shape of the metal nanoparticle sol flowing in the described microchannel unit is spherical, and the diameter of spherical particle is 50nm～ 200nm. 5. NERS-SERS substrate microfluidic photoquantum material fingerprint target according to claim 1, is characterized in that, described metal nanoparticle sol memory and described metal nanoparticle sol recovery device are the container structure of cuboid; The metal nanoparticle sol memory has a length of 1000 μm to 5000 μm, a width of 1000 μm to 5000 μm, and a depth of 50 μm to 200 μm; the metal nanoparticle sol recovery device has a length of 1000 μm to 5000 μm, a width of 1000 μm to 5000 μm, and a depth of 50 μm to 200 μm . 6. The NERS-SERS substrate microfluidic optical quantum substance fingerprint target according to claim 1, wherein the first-level microfluidic channel and the fourth-level microfluidic channel are elongated channel structures, Its cross section is rectangular or circular; the length of the first-stage microchannel is 1 mm to 5 mm, the width is 100 μm to 500 μm, and the depth is 50 μm to 200 μm; the length of the fourth-stage microchannel is 1 mm ～5mm, the width is 100μm～500μm, and the depth is 50μm～200μm. 7. The NERS-SERS substrate microfluidic optical quantum substance fingerprint target according to claim 1, wherein the width of each capillary microchannel in the second-stage microchannel is 10 μm to 30 μm, and the length is 1 mm ～5mm, and the depth is 5μm～20μm. 8. NERS-SERS substrate microfluidic photoquantum substance fingerprint target according to claim 1, is characterized in that, described third-level microfluidic channel is elongated channel structure; The length of described third-level microfluidic channel 0.2 mm to 2 mm in width, 100 μm to 500 μm in width, and 5 μm to 20 μm in depth. 9. The NERS-SERS substrate microfluidic photoquantum substance fingerprint target according to claim 1, wherein the first miniature temperature sensor is 2 mm to 5 mm from the bottom of the metal nanoparticle sol recoverer; The distance from the miniature heating sheet to the lower bottom of the metal nanoparticle sol recovery device is 5 mm to 15 mm. 10. The NERS-SERS substrate microfluidic photoquantum substance fingerprint target according to claim 1, wherein the second miniature temperature sensor is 2 mm to 5 mm from the bottom of the metal nanoparticle sol memory; The cooling sheet is 5 mm to 15 mm away from the bottom of the metal nanoparticle sol storage.