A near-infrared SPR portable detection device

Abstract

The present invention relates to a near-infrared SPR portable detection device, comprising: a laser emission module, an SPR excitation module, a photoelectric detection module and a signal processing module. Among them, the laser emission module is used to emit C-band laser and incident the C-band laser on the SPR excitation module; the SPR excitation module includes a prism and a sensing chip; after the C-band laser is sequentially incident on the prism and the sensing chip, it irradiates the analyte on the sensing chip to excite the SPR effect, and the reflected light with the SPR effect is sequentially detected by the photoelectric detection module after passing through the sensing chip and the prism; the signal processing module is used to determine the refractive index of the analyte according to the signal detected by the photoelectric detection module. This application is based on the SPR effect in the near-infrared range to realize the detection of the refractive index of the analyte. Compared with the existing detection devices using spectrometers, the volume of the device is reduced, and the detection sensitivity is ensured.

Description

Technical Field

[0001] The present invention relates to the field of Surface Plasmon Resonance (SPR) sensing, and particularly to a near-infrared SPR portable detection device. Background Art

[0002] In recent years, with the rapid development of various new materials and new technologies, as the research frontier in the field of sensing technology, the development of biochemical sensors has shown characteristics such as miniaturization and integration. SPR sensing technology is a new type of optoelectronic detection technology. Compared with traditional biochemical sensors, it has the advantages of simple equipment, high sensitivity, good stability, and fast response speed. It has been widely used and gradually matured in many important fields such as medicine, biology, environment, food detection, and pharmaceuticals, and has good development prospects. Sensors and detectors based on SPR sensing technology have good sensitivity and resolution in detecting the refractive index of the medium.

[0003] Currently, commercially available SPR detection instruments mainly focus on prism-coupled angle modulation type and wavelength modulation type. Although the detection accuracy is relatively high, their structures are complex and the volumes are large, which are not suitable for portable measurement, and the application and promotion are greatly restricted. To achieve the portability and miniaturization of SPR sensing devices, the current mainstream solutions include two major categories: (1) using optical fibers or waveguides to replace prism-coupling elements to compress the optical path space; (2) using image acquisition or spectral reconstruction methods to replace spectrometers to reduce the volume of optical devices. However, both of the above methods sacrifice the SPR sensing sensitivity to achieve the purpose of miniaturization, so the sensor sensitivity is relatively low. Summary of the Invention

[0004] The purpose of the present invention is to provide a near-infrared SPR portable detection device to achieve both miniaturization and high sensitivity.

[0005] To achieve the above purpose, the present application provides the following solutions:

[0006] A near-infrared SPR portable detection device, comprising: a laser emission module, an SPR excitation module, a photoelectric detection module, and a signal processing module;

[0007] The laser emission module is used to emit C-band laser and incident the C-band laser onto the SPR excitation module;

[0008] The SPR excitation module includes a prism and a sensing chip; after the C-band laser is sequentially incident on the prism and the sensing chip, the near-infrared SPR effect is excited, and the SPR evanescent field radiates onto the analyte in the near field of the sensing chip. The reflected light with SPR absorption characteristics and the refractive index information of the analyte is sequentially detected by the photoelectric detection module after passing through the sensing chip and the prism;

[0009] The signal processing module is configured to determine the refractive index of the analyte according to the signal detected by the photoelectric detection module.

[0010] Optionally, it further includes: an incident light fiber collimator and a reflected light fiber collimator;

[0011] The incident light fiber collimator is arranged on the optical path of the C-band laser incident on the SPR excitation module for collimating the C-band laser;

[0012] The reflected light fiber collimator is arranged on the optical path of the reflected light with SPR effect to the photoelectric detection module for collimating the reflected light with SPR effect.

[0013] Optionally, the photoelectric detection module includes an indium gallium arsenide photodetector.

[0014] Optionally, the laser emission module includes an optical fiber laser transmitter and a C-band laser diode. The optical fiber laser transmitter generates laser light, and the laser light is incident on the C-band laser diode, which is used to generate C-band laser light.

[0015] Optionally, the prism is a K9 rectangular prism.

[0016] Optionally, the sensing chip includes: a K9 glass sheet and a metal sensing film modified with a specific detection molecular film, and the sensing film is arranged on the K9 glass sheet.

[0017] Optionally, the sensing chip is a detachable sensing chip, and the material and thickness of the sensing film modified on the surface of the sensing chip are determined according to the type of the analyte.

[0018] Optionally, the signal processing module includes a signal converter and a processor. The signal converter is used to convert the optical signal detected by the laser receiving module into an electrical signal, and the processor is used to determine the optical intensity information corresponding to the electrical signal, and the optical intensity information is used to calculate the refractive index of the analyte.

[0019] According to the specific embodiments provided by the present invention, the following technical effects are disclosed: The present application provides a near-infrared SPR portable detection device, which includes a laser emission module, an SPR excitation module, a photoelectric detection module, and a signal processing module. Among them, the laser emission module is used to emit C-band laser and incident the C-band laser on the SPR excitation module; the SPR excitation module includes a prism and a sensing chip; the C-band laser is successively incident on the prism and the sensing chip to excite the SPR effect, and the SPR evanescent field radiates to the object to be measured in the near field of the sensing chip. The reflected light with the SPR effect is successively detected by the photoelectric detection module after passing through the sensing chip and the prism; the signal processing module is used to determine the refractive index of the object to be measured according to the signal detected by the photoelectric detection module. Since the present application is based on the near-infrared SPR effect, the detection of the refractive index of the object to be measured is realized. Compared with the existing detection device using a spectrometer, the volume of the device is reduced, and at the same time, the detection sensitivity can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 Schematic diagram of the internal structure of the detection device provided by the present application;

[0022] Figure 2 Schematic diagram of the external structure of the detection device provided by the present application;

[0023] Figure 3 Schematic diagram of the laser incident angle provided by the present application;

[0024] Figure 4 Schematic diagram of the device size provided by the present application;

[0025] Figure 5 Schematic diagram of the enhancement of near-infrared SPR sensitivity provided by the present application, Figure 5 (a) shows the variation of the SPR spectrum of traditional visible light with the refractive index, Figure 5 (b) shows the variation of the SPR spectrum of near-infrared light with the refractive index, Figure 5 (c) shows the comparison result of the SPR spectra of traditional visible light and near-infrared light of the present invention with the refractive index.

[0026] Symbol Explanation: 1 - Fiber laser emitter; 2 - C-band laser diode; 3 - Incident light fiber collimator; 4 - K9 rectangular prism; 5 - K9 glass sheet; 6 - Sensing film modified with specific detection molecular film; 7 - Reflected light fiber collimator; 8 - Indium gallium arsenide photodetector; 9 - Microprocessor; 10 - IV converter; 11 - Power supply device; 12 - Transmission fiber; 13 - Instrument housing; 14 - Power button; 15 - Connection bracket; 16 - USB port; 17 - Charging port; 18 - Glass sheet bayonet; 19 - Handle; 20 - Heat dissipation hole. Detailed Implementation Manner

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0028] The purpose of the present application is to provide a near-infrared SPR portable detection device.

[0029] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0030] The present application provides a near-infrared SPR portable detection device, including a laser emission module, an SPR excitation module, a photoelectric detection module, and a signal processing module.

[0031] Among them, the laser emission module is used to emit C-band laser and incident the C-band laser to the SPR excitation module; the SPR excitation module includes a K9 rectangular prism 4 and a sensing chip; after the C-band laser is incident into the K9 rectangular prism 4 and the sensing chip in sequence, it irradiates the object to be measured on the sensing chip, exciting the SPR effect, and the reflected light with the SPR effect is detected by the photoelectric detection module after passing through the sensing chip and the prism in sequence; the signal processing module is used to determine the refractive index of the object to be measured according to the signal detected by the photoelectric detection module.

[0032] Specifically, the C-band laser is obliquely incident on the sensing chip at a small angle to excite the near-infrared SPR effect, and the reflected light with the SPR effect and the refractive index information of the object to be measured is detected by the photoelectric detection module after passing through the prism.

[0033] In some embodiments, the specific structure of the near-infrared SPR portable detection device is as Figure 1 , 2 shown, and the specific structure is as follows:

[0034] The outer surface of the instrument housing 13 of the detection device has a handle 19, a glass slide bayonet 18, heat dissipation holes 20, a power button 14, a charging port 17, and a USB port 16. Among them, the handle 19 and the glass slide bayonet 18 are located above the instrument housing 13, the heat dissipation holes 20 are located on the left and right sides of the instrument housing 13, and the charging port 17 and the USB port 16 are located on the front side of the instrument housing 13.

[0035] In the internal structure of the detection device, the fiber laser emitter 1, the C-band laser diode 2, the power supply device 11, and the microprocessor 9 are located inside the instrument and are fixedly connected to the instrument housing 13 by screws.

[0036] The fiber laser emitter 1 is connected to the microprocessor 9 by a wire and is connected to the C-band laser diode 2 through a transmission fiber. Among them, the fiber laser emitter 1 generates laser light, and the laser light is incident on the C-band laser diode to generate C-band laser light.

[0037] The C-band laser diode 2 is connected to the incident light fiber collimator 3.

[0038] There is a connecting bracket 15 inside the instrument, which is located above the power supply device 11, supports the K9 rectangular prism 4 and fixes the incident light fiber collimator 3 and the reflected light fiber collimator 7, and customizes the connecting bracket 15. Among them, the incident light fiber collimator 3 is arranged on the optical path of the C-band laser incident on the SPR excitation module and is used to collimate the C-band laser; the reflected light fiber collimator 7 is arranged on the optical path of the reflected light with the SPR effect to the photoelectric detection module and is used to collimate the reflected light with the SPR effect.

[0039] The K9 rectangular prism 4 is placed on the connecting bracket 15 and contacts the upper surface of the instrument, and is located below the glass slide bayonet 18.

[0040] The K9 glass slide 5 and the sensing film 6 modified with a specific detection molecular film are placed on the K9 rectangular prism 4, and the sensing film 6 is arranged on the K9 glass slide 5. Among them, the sensing film 6 modified with a specific detection molecular film is a detachable sensing film. For different detection substances, the corresponding biomolecular film system is modified, and different detection substances are detected by replacing the corresponding sensing film on the top of the instrument. For example, a gold film with a thickness of 35 nm is a commonly used sensing film for the detection device.

[0041] The reflected light fiber collimator 7 is connected to the indium gallium arsenide photodetector 8 and is used to detect the reflected light intensity and convert the optical signal into an electrical signal.

[0042] The indium gallium arsenide photodetector 8 is used to receive the signal of near-infrared light and is connected to the IV converter 10 by a wire; the IV converter 10 and the microprocessor 9 are connected by a wire. Among them, the IV converter 10 can convert the electrical signal into a voltage signal and send the voltage signal to the microprocessor 9.

[0043] The microprocessor 9 includes an Arduino NANO development board and a pin expansion board. The microprocessor 9 is connected to the C-band laser diode 2 and the indium gallium arsenide photodetector 8 through wires, can receive the light intensity information collected by the laser detection device in real time, and has a USB port 16. The USB port 16 is located on the front side of the instrument housing 13, can be connected to a computer, and transfers the collected light intensity information to the computer in real time.

[0044] The power supply device 11 includes a DC charging battery pack and a power voltage conversion circuit board, which is used to supply power to the fiber laser transmitter and the IV converter 10.

[0045] The computer is used to receive the light intensity information transmitted by the microprocessor in real time, process the light intensity information, and detect the refractive index of the object to be measured in real time.

[0046] Specifically, in the detection device, each part of the optical element is fixed by a connecting bracket, the optical path is connected by a transmission optical fiber, integrated into the internal structure of the detection device, and the instrument is connected to the computer using a USB cable.

[0047] In some embodiments, as Figure 3 shown, when detecting the object to be measured, the specific use steps are as follows:

[0048] 1) Turn on the power and start the detection device.

[0049] 2) Open the lid on the top of the instrument housing, select a sensing chip that matches the object to be measured. Here, a 35-nm-thick gold film modified with a specific detection molecular film is plated on a K9 glass sheet as the sensing chip, and is placed at the sensing chip slot.

[0050] 3) Adjust the angle between the laser emitted by the C-band laser diode and the left side of the K9 rectangular prism to 45°, and the angle between the incident light in the prism and the contact surface of the sensing chip to 28°.

[0051] 4) Adjust the angle between the reflected light detected by the indium gallium arsenide photodetector and the right side of the K9 rectangular prism to 45°, and the angle between the reflected light in the prism and the sensing chip to 28°.

[0052] 5) Turn on the light source, record the background light, and set the sampling frequency.

[0053] 6) Drop the sample to be measured onto the sensing chip to excite the SPR effect.

[0054] 7) The computer receives the light intensity information transmitted by the microprocessor in real time, processes the light intensity information, detects the refractive index of the object to be measured in real time, and its application interface displays the real-time detection data to obtain the refractive index and the real-time dynamic change of the object to be measured.

[0055] In some embodiments, asFigure 5 As shown, taking the refractive index in the range of 1.331 - 1.333 as an example, the SPR spectra of traditional visible light and the near-infrared light of the present invention with respect to the change in refractive index and the difference in sensitivity are observed.

[0056] Specifically, Figure 5 (a) shows the change in the SPR spectrum of traditional visible light with respect to the change in refractive index. The traditional visible light SPR light source is generally about 560 nm. When the refractive index changes from 1.331 to 1.333, the received intensity corresponds to the points where the vertical line intersects the three curves. At this time, the intensity change is about 0.15.

[0057] Figure 5 (b) shows the change in the SPR spectrum of near-infrared light with respect to the change in refractive index. The near-infrared SPR light source is about 1510 nm. For the same change in refractive index, the change amplitude of the received intensity is larger. When the refractive index changes from 1.331 to 1.333, the received intensity corresponds to the points where the vertical line intersects the three curves. At this time, the intensity change is about 0.45.

[0058] It can be seen by comparison that for the same change in refractive index, the intensity-modulated near-infrared SPR effect has a larger intensity change. Figure 5 (c) is the comparison result. It can be seen that the intensity sensitivity of the present invention (220 a.u. / RIU) is increased by about 3 times compared with the intensity sensitivity of the traditional SPR sensor (75 a.u. / RIU).

[0059] In summary, the present application has the following advantages: 1) The near-infrared SPR portable detection device provided by the present application, compared with the detection instruments with higher detection accuracy in the prior art, detects the refractive index of the object to be measured by using the near-infrared SPR effect and intensity demodulation technology, replaces the spectrometer with an indium gallium arsenide photodetector, reduces the volume of optical devices, and realizes the portability and miniaturization of the SPR sensing device. 2) The near-infrared SPR portable detection device provided by the present application, compared with the miniaturized SPR device in the prior art, uses the near-infrared SPR effect and intensity demodulation technology to detect the refractive index of the object to be measured. Since the laser wavelength used is in the C band, the near-infrared SPR effect is excited, improving the detection sensitivity and achieving both miniaturization and high sensitivity.

[0060] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0061] In this text, specific examples are used to illustrate the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation on the present invention.

Claims

1. A near-infrared SPR portable detection device, characterized in that, it includes: a laser emission module, an SPR excitation module, a photoelectric detection module, and a signal processing module; the laser emission module is used to emit C-band laser and incident the C-band laser onto the SPR excitation module; the SPR excitation module includes a prism and a sensing chip; after the C-band laser is sequentially incident into the prism and the sensing chip, the near-infrared SPR effect is excited, and the SPR evanescent field radiates on the near-field analyte of the sensing chip. The reflected light with SPR effect and analyte refractive index information is sequentially detected by the photoelectric detection module after passing through the sensing chip and the prism; the signal processing module is used to determine the refractive index of the analyte according to the signal detected by the photoelectric detection module.

2. The near-infrared SPR portable detection device according to claim 1, characterized in that, it further includes: an incident light fiber collimator and a reflected light fiber collimator; the incident light fiber collimator is arranged on the optical path of the C-band laser incident onto the SPR excitation module and is used to collimate the C-band laser; the reflected light fiber collimator is arranged on the optical path of the reflected light with SPR effect to the photoelectric detection module and is used to collimate the reflected light with SPR effect.

3. The near-infrared SPR portable detection device according to claim 1, characterized in that, the photoelectric detection module includes an indium gallium arsenide photodetector.

4. The near-infrared SPR portable detection device according to claim 1, characterized in that, the prism is a K9 rectangular prism.

5. The near-infrared SPR portable detection device according to claim 1, characterized in that, the sensing chip includes: a K9 glass sheet and a sensing film modified with a specific detection molecular film, and the sensing film is arranged on the K9 glass sheet.

6. The near-infrared SPR portable detection device according to claim 5, characterized in that, the sensing film is a detachable sensing film, and the material and thickness of the sensing film are determined according to the type of the analyte.

7. The near-infrared SPR portable detection device according to claim 1, characterized in that, the signal processing module includes a signal converter and a processor. The signal converter is used to convert the optical signal detected by the laser receiving module into an electrical signal, and the processor is used to determine the light intensity information corresponding to the electrical signal, and the light intensity information is used to calculate the refractive index of the analyte.

Images