A detection method for a miniaturized multi-channel terminal reflection optical fiber SPR detector based on optical switch

Abstract

A miniaturized multi-channel terminal reflection type optical fiber SPR detector based on an optical switch and a detection method thereof, relating to the field of optical fiber sensing technology. Aiming at the problem that the existing SPR detection instrument is bulky and expensive; the multi-channel detection is less and cannot meet the accuracy of the inspection, the present invention provides a detector, including: a light source, an optical switch, an optical fiber coupler, a 1×2Y type optical fiber jumper, an optical fiber SPR sensor, a 1×4Y type optical fiber jumper, a spectrometer, a microprocessor, a fan, a power supply module and a signal transmission module; the optical switch connects the light source and the optical fiber coupler, the input end of the 1×2Y type optical fiber jumper is connected to the optical fiber coupler, the other input end is connected to the optical fiber SPR sensor, the input end of the 1×4Y type optical fiber jumper is connected to the output end of the 1×2Y type optical fiber jumper, the output end is connected to the spectrometer, the spectrometer is connected to the microprocessor, the signal transmission module is connected to the microprocessor, and the fan is connected to the microprocessor. Suitable for application in the field of biosensing.

Description

Technical Field

[0001] The invention relates to the technical field of optical fiber sensing, and in particular to an optical fiber SPR detector and a detection method applied to biological detection. Background Art

[0002] Fiber optic sensing technology has been popularized in all aspects of our lives. Fiber optic sensing technology has the advantages of small size, light weight, fast response, high temperature resistance, high sensitivity, corrosion resistance and high biocompatibility. It is often used in various fields such as physics, chemistry, industrial monitoring, and life detection. SPR detection technology is a new type of optical detection technology, surface plasma resonance, that is, Surface Plasmon Resonance; SPR technology has a wide range of applications in biotechnology, health care, life science and technology research, food safety, and ecological environment monitoring. The SPR phenomenon is a physical optical phenomenon. When light shines on the interface between metal (usually gold or silver) and a total reflection medium, an evanescent wave is generated. The evanescent wave will propagate downward for a distance and excite the free electrons in the metal film to generate surface plasma waves. The matching of the two wave vectors will excite the SPR phenomenon. The SPR sensor made using this characteristic is often used in the field of biosensing because of its high sensitivity and strong detection accuracy. It is also a very good method for detecting the refractive index of the external environment.

[0003] SPR sensing technology has the advantages of high resolution, high sensitivity, and low cost, and is widely used in biology, chemistry, life sciences, and other fields. However, most of the existing traditional SPR detection instruments are designed based on prism-type SPR sensors, and there are very few instruments designed based on optical fiber SPR sensors. In addition, with commercialization, SPR detection instruments are bulky and expensive, and are only limited to laboratory use and cannot be applied to actual field detection. At the same time, there are relatively few instruments that realize detection through multi-channels, and sometimes they cannot meet the accuracy and reliability of the test, which brings some obstacles to the application and development of SPR sensing technology. Therefore, it is very necessary to provide a miniaturized multi-channel wavelength-modulated SPR detector for field detection. Summary of the invention

[0004] In view of the fact that there are few instruments designed based on optical fiber SPR sensors in the prior art, the SPR detection instruments are bulky and expensive, and are only limited to laboratory use and cannot be applied to actual field detection; at the same time, there are relatively few instruments that realize detection through multiple channels, and the accuracy and reliability of the inspection cannot be met, the present invention provides a miniaturized multi-channel terminal reflection optical fiber SPR detector based on an optical switch, which is based on the optical fiber SPR design, the instrument is compact and can realize multi-channel detection, specifically:

[0005] A miniaturized multi-channel terminal reflection type optical fiber SPR detector based on an optical switch, the detector comprising: a light source, an optical switch, four optical fiber couplers, four 1×2Y optical fiber jumpers, four optical fiber SPR sensors, a 1×4Y optical fiber jumper, a spectrometer, a microprocessor, a fan, a power supply module and a signal transmission module; the optical signal output by the light source is simultaneously sent to the four optical fiber couplers through the optical switch, the optical signals output by the four optical fiber couplers are respectively input to the optical signal acquisition end of the spectrometer through four 1×2Y optical fiber jumpers and a 1×4Y optical fiber jumper, the ends of the four optical fiber SPR sensors away from the reflection ends are respectively embedded in one port of the four 1×2Y optical fiber jumpers, the spectrometer is connected to the microprocessor through a serial communication line, the signal transmission module is connected to the microprocessor through a serial communication line, the control signal input end of the fan is connected to the fan control signal output end of the microprocessor, and the power supply module is used for providing working power to the light source, the optical switch, the microprocessor and the signal transmission module.

[0006] Preferably, the optical fiber coupler is a SMA905 optical fiber coupler.

[0007] Preferably, the signal transmission module is implemented using a WIFI module.

[0008] Furthermore, the detector also includes: a shell; four sensor fixing holes are arranged on the side wall of the shell; the light source, optical switch, four fiber optic couplers, four 1×2Y fiber optic jumpers, four fiber optic SPR sensors, 1×4Y fiber optic jumper, spectrometer, microprocessor, power supply module and signal transmission module are all arranged inside the shell, the sensor fixing holes are through holes arranged on the side wall of the shell, and the four fiber optic SPR sensors pass through the four sensor fixing holes, protrude from the shell and are fixed.

[0009] Preferably, the shell includes: a bottom partition and a middle partition; the bottom partition and the middle partition are parallel to the bottom surface of the shell, dividing the internal space of the shell into three areas: an upper layer, a middle layer and a lower layer; the light source, the optical switch and the fan are arranged in the lower layer area, the spectrometer and the power supply module are arranged in the middle layer area, and the microprocessor and the signal transmission module are arranged in the upper layer area.

[0010] Preferably, the detector comprises two fans, and the other fan is arranged in the upper area.

[0011] Preferably, the four sensor fixing holes are arranged on the side wall of the lower area of ​​the shell.

[0012] Based on the same inventive concept, the present invention also provides a miniaturized multi-channel terminal reflective optical fiber SPR detection method based on an optical switch, wherein the method is implemented based on the miniaturized multi-channel terminal reflective optical fiber SPR detector based on an optical switch, specifically:

[0013] The method includes:

[0014] A parameter setting step, setting the parameters of the detector;

[0015] A spectrum collection step, collecting four sets of background light and dark spectrum data through the four optical fiber SPR sensors, and transmitting the data to the microprocessor through the spectrometer;

[0016] A buffer data writing step, sending the processing result of the microprocessor to the buffer;

[0017] a sending judgment step, in which the terminal selects whether to send the external signal sent by the signal transmission module. If the terminal selects to send, the data in the buffer is used as a real-time spectrum through the signal transmission module; if the terminal selects not to send, the terminal enters a stop judgment step;

[0018] In the stop judgment step, the terminal selects whether to stop through the external signal sent by the signal transmission module. If it is selected to stop, the method is terminated; if it is not selected to stop, it returns to the sending judgment step.

[0019] Preferably, the parameter setting step specifically includes: setting the parameters of the baud rate, stop bit and parity bit.

[0020] Preferably, the parameter setting step includes: setting the parameters of the spectrometer.

[0021] The present invention is beneficial in that:

[0022] The optical fiber SPR sensor has the advantages of small size, low cost and anti-electromagnetic interference. The modules in the instrument are integrated into the shell and arranged in layers, and the precision devices such as the light source and the spectrometer are separated in different areas, so as to avoid the problem of mutual fluctuation between devices and the influence on the experimental data. At the same time, they are set separately and equipped with fans respectively to ensure the heat dissipation of the instrument. By integrating into the shell in the above way, the instrument becomes compact and the cost is lower.

[0023] By using optical switches for multi-channel measurement, multiple tests and the same test can be performed on the samples to be tested, which increases the diversity and accuracy of the detection system.

[0024] The design of the terminal reflection fiber SPR sensor further increases the miniaturization and portability of the instrument. Fiber optic detection can achieve pollution-free and high-sensitivity detection, which is more suitable for application in the field of small molecules in biological detection.

[0025] The system integration method is flexible, and each module is well organized and can work together with the hardware system at the same time.

[0026] The power supply method is flexible, the power consumption is very low, and it is detachable, with an intelligent and automated working method.

[0027] Suitable for application in the field of biosensing. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the principle of a miniaturized multi-channel terminal reflection optical fiber SPR detector based on an optical switch provided in Embodiment 1;

[0029] Figure 2 A schematic diagram of the internal layout structure of a housing of a miniaturized multi-channel terminal reflective optical fiber SPR detector based on an optical switch provided in Embodiment 4;

[0030] Figure 3 , Figure 4 A schematic diagram of the three-dimensional structure of a miniaturized multi-channel terminal reflective optical fiber SPR detector based on an optical switch provided in Embodiment 4;

[0031] Figure 5 A flowchart of a miniaturized multi-channel terminal reflective optical fiber SPR detection method based on an optical switch provided in Embodiment 8;

[0032] Figure 6 A schematic diagram of a miniaturized multi-channel optical fiber SPR detection system provided for implementation example eight;

[0033] Figure 7 A schematic diagram of the main body of the optical fiber SPR sensor provided in Embodiment 1;

[0034] Among them, 1 represents a light source; 2 represents an optical switch; 3 represents an SMA905 optical fiber coupler; 4 represents a 1×2Y optical fiber patch cord; 5 represents an optical fiber SPR sensor; 6 represents a 1×4Y optical fiber patch cord; 7 represents a spectrometer; 8 represents a switch; 9 represents a microprocessor; 10 represents a touch screen; 11 represents a fan; 12 represents a signal transmission module; 13 represents a power supply module; 14 represents a housing; 15 represents a bottom partition; 16 represents a middle partition; 17 represents a sensor fixing hole; 19 represents a charging hole; 201 represents a heat dissipation hole; 501 represents a sensing area; and 502 represents a reflection area. DETAILED DESCRIPTION

[0035] In order to describe the advantages and benefits of the technical solution provided by the present invention more specifically, the technical solution provided by the present invention is now further described in detail in conjunction with the accompanying drawings, specifically:

[0036] Implementation Method 1: Combination Figure 1 and 7 The present embodiment is described. The present embodiment provides a miniaturized multi-channel terminal reflection type optical fiber SPR detector based on an optical switch. The detector comprises: a light source 1, an optical switch 2, four optical fiber couplers 3, four 1×2Y optical fiber jumpers 4, four optical fiber SPR sensors 5, a 1×4Y optical fiber jumper 6, a spectrometer 7, a microprocessor 9, a fan 11, a power supply module 13 and a signal transmission module 12; the optical signal output by the light source 1 is simultaneously sent to the four optical fiber couplers 3 through the optical switch 2, and the optical signals output by the four optical fiber couplers 3 are respectively transmitted through the four 1×2Y optical fiber jumpers 4, the 1× The 4Y-type optical fiber jumper 6 is input to the optical signal collection end of the spectrometer 7, the ends of the four optical fiber SPR sensors 5 away from the reflection end are respectively embedded in a port of the four 1×2Y-type optical fiber jumpers 4, the spectrometer 7 is connected to the microprocessor 9 through a serial communication line, the signal transmission module 12 is connected to the microprocessor 9 through a serial communication line, the control signal input end of the fan 11 is connected to the fan control signal output end of the microprocessor 9, and the power supply module 13 is used to provide working power to the light source 1, the optical switch 2, the microprocessor 9 and the signal transmission module 12.

[0037] Specifically, the optical fiber SPR sensor 5 is a terminal reflection optical fiber SPR sensor 5, and its preparation method is:

[0038] Step 1: Select a 90mm multimode quartz optical fiber, remove the cladding coating layer from the optical fiber terminal and the middle area under a microscope, put it in ethanol and then put it in an ultrasonic cleaner for cleaning for 15 minutes, and use a magnetron sputtering coater to coat 50nm gold film on both ends, with a evaporation time of 2min30s and a current of 20mA as the SPR effect excitation area.

[0039] Step 2: Prepare 1 mmol / L mercaptoundecanoic acid, namely , wherein the thiol end of the element can be connected to the gold atom on the SPR sensor, and the carboxyl group at the other end can be combined with the protein. The optical fiber SPR sensor 5 is immersed in it for 12 hours, so that enough thiol undecanoic acid can be attached to the gold film.

[0040] Step 3: Place the SPR sensor treated in step 2 into 0.5 mol / L EDC and 0.6 mol / L NHS The purpose is to activate the carboxyl groups on the surface of the SPR sensor.

[0041] Step 4: Take out the SPR sensor in step 3, rinse it with deionized water for 3 minutes, blow it dry with nitrogen, and put it into the 0.08 mg / mL ribonuclease B Soak in the solution for 40 minutes to allow antibodies to grow on the surface of the gold film for binding to the antigen.

[0042] Step 5: Take out the SPR sensor from step 4, rinse and dry it, and put it into a 0.5 mg / mL bovine serum albumin solution. The purpose of encapsulation is to seal the carboxyl groups that cannot be connected to the groups, so as to prevent the error caused by the detection from affecting the experimental results. The BSA was sealed for 20 minutes, and the fiber SPR biosensor was completed.

[0043] In the terminal reflective structure, by coating the reflective surface with a metal film, the sensor can be better placed in the medium to be tested for detection, which increases portability to a certain extent.

[0044] The detection range of the spectrometer 7 is 200-1100nm.

[0045] The light source 1 is a halogen light source 1 with a wavelength range of 360-2500nm.

[0046] The optical switch 2 is a mechanical optical switch 2 .

[0047] The SPR sensor has a sensing area 501 and a reflection area 502. The sensing area 501 is responsible for detection, and the reflection area 502 is responsible for returning the signal and transmitting it to the spectrometer through a 1×4Y optical fiber jumper.

[0048] Embodiment 2: This embodiment further limits the miniaturized multi-channel terminal reflective optical fiber SPR detector based on optical switch provided in Embodiment 1, and the optical fiber coupler 3 is a SMA905 optical fiber coupler 3 .

[0049] Embodiment 3: This embodiment further limits the miniaturized multi-channel terminal reflective optical fiber SPR detector based on optical switch provided in Embodiment 1, and the signal transmission module 12 is implemented by a WIFI module.

[0050] Implementation Method 4: Combination Figure 2-4The present embodiment is described. The present embodiment is a further limitation of the miniaturized multi-channel terminal reflective optical fiber SPR detector based on an optical switch provided in the first embodiment. The detector further comprises: a housing 14; four sensor fixing holes 17 are arranged on the side wall of the housing 14; the light source 1, the optical switch 2, four optical fiber couplers 3, four 1×2Y optical fiber jumpers 4, four optical fiber SPR sensors 5, a 1×4Y optical fiber jumper 6, a spectrometer 7, a microprocessor 9, a power supply module 13 and a signal transmission module 12 are all arranged inside the housing 14; the sensor fixing holes 17 are through holes arranged on the side wall of the housing 14; the four optical fiber SPR sensors 5 pass through the four sensor fixing holes 17, protrude from the housing 14 and are fixed.

[0051] A touch screen 10 is also provided on the top of the housing 14 , and the touch screen 10 is connected to the microprocessor 9 to realize information interaction between the operator and the microprocessor.

[0052] The side wall of the housing 14 is also provided with heat dissipation holes 201 . There are two types of heat dissipation holes 201 . One is a circular through hole provided on the rear side wall of the detector, and the other is a long strip through hole provided on the left side wall of the detector.

[0053] By integrating various modules in the instrument into the housing 14, the instrument becomes compact and has a lower cost.

[0054] In addition, the shell 14 is provided to reduce optical fiber interference and electromagnetic interference, so that the detector has small size, light weight, no pollution, good portability, high integration and strong practicality, and can be used for real-time detection in the field.

[0055] The housing 14 is detachable, which is convenient for maintenance, cleaning, repair and servicing of the detector.

[0056] Implementation Method 5: Combination Figure 2-4 The present embodiment is described. The present embodiment is a further limitation of the miniaturized multi-channel terminal reflective optical fiber SPR detector based on an optical switch provided in the fourth embodiment. The shell comprises: a bottom partition and a middle partition; the bottom partition and the middle partition are parallel to the bottom surface of the shell, and divide the internal space of the shell into three areas: an upper layer, a middle layer and a lower layer; the light source, the optical switch and the fan are arranged in the lower layer area, the spectrometer and the power supply module are arranged in the middle layer area, and the microprocessor and the signal transmission module are arranged in the upper layer area.

[0057] Implementation Method 6: Combination Figure 2-4This embodiment is described as a further limitation of the miniaturized multi-channel terminal reflective optical fiber SPR detector based on optical switches provided in the fifth embodiment. The detector includes two fans, and the other fan is arranged in the upper area.

[0058] Separating the light source 1 and the spectrometer 7 and other precision devices in different areas avoids the problem of mutual fluctuations between the devices and the impact on the experimental data. At the same time, they are separately set and equipped with fans 11 to ensure the heat dissipation of the instrument.

[0059] The power supply module 13 is implemented by a battery;

[0060] A charging hole 19 is also provided on the rear side wall of the detector for connecting a charging cable to charge the battery;

[0061] A main switch 8 is also provided on the rear side wall of the detector for controlling the on and off of the battery.

[0062] Implementation Method 7: Combination Figure 2-4 This embodiment is described as a further limitation of the miniaturized multi-channel terminal reflective optical fiber SPR detector based on an optical switch provided in the fourth embodiment. The four sensor fixing holes 17 are arranged on the side wall of the lower area of ​​the shell 14.

[0063] Implementation Method 8: Combination Figure 5-6 This embodiment is described. This embodiment provides a miniaturized multi-channel terminal reflective optical fiber SPR detection method based on an optical switch. The method is implemented based on a miniaturized multi-channel terminal reflective optical fiber SPR detector based on an optical switch provided in Embodiment 1. Specifically:

[0064] The method includes:

[0065] A parameter setting step, setting the parameters of the detector;

[0066] Spectrum acquisition step, collecting four sets of background light and dark spectrum data through the four optical fiber SPR sensors 5, and transmitting the data to the microprocessor 9 through the spectrometer 7;

[0067] A buffer data writing step, sending the processing result of the microprocessor 9 to the buffer;

[0068] The sending judgment step is to select whether to send the external signal sent by the terminal through the signal transmission module 12. If the external signal is sent, the data in the buffer is used as a real-time spectrum through the signal transmission module 12; if the external signal is not sent, the terminal enters the stop judgment step;

[0069] In the stop judgment step, the terminal selects whether to stop through the external signal sent by the signal transmission module 12. If it is selected to stop, the method is terminated; if it is not selected to stop, it returns to the sending judgment step.

[0070] The multi-channel detection software is written using LabVIEW software, which has internal drivers for controlling the spectrometer 7, the optical switch 2, etc., and also has functions such as spectrum acquisition, image processing, storage and display.

[0071] The multi-channel software integration part consists of four parts: data transmission system, data processing system, real-time observation system and integrated display system. Among them, the data transmission system mainly includes VISA serial communication protocol transmission, real-time display inspection and user prompts. In the data processing system, the spectrometer 7 setting operation, data storage, instrument switch, data fitting calculation, etc. are required. In the real-time observation system, it is necessary to switch parameters during the detection process, command sending and receiving, and pay attention to the real-time situation of the front panel. In the integrated display system, the optical switch 2 must be set and displayed, and the multi-channel, single-channel and detection spectrum must be displayed in real time.

[0072] Embodiment 9: This embodiment further limits the miniaturized multi-channel optical fiber SPR detection device provided in embodiment 8, and the parameter setting step is specifically: setting the parameters of the baud rate, stop bit and parity bit.

[0073] Embodiment 10: This embodiment further limits the miniaturized multi-channel optical fiber SPR detection device provided in embodiment 9, and the parameter setting step includes: setting the parameters of the spectrometer.

[0074] The above further describes in detail the technical solution provided by the present invention in conjunction with the accompanying drawings in order to highlight the advantages and benefits, and is not intended to be a limitation of the present invention. Any modification, combination of implementation modes, improvement and equivalent substitution of the present invention within the spirit and scope of the present invention shall be included in the protection scope of the present invention.

Claims

1. A detection method of a miniaturized multi-channel terminal reflection optical fiber SPR detector based on an optical switch, the detector comprising: A light source (1), an optical switch (2), four optical fiber couplers (3), four 1×2Y optical fiber jumpers (4), four optical fiber SPR sensors (5), a 1×4Y optical fiber jumper (6), a spectrometer (7), a microprocessor (9), a fan (11), a power supply module (13) and a signal transmission module (12); the optical signal output by the light source (1) is simultaneously sent to the four optical fiber couplers (3) through the optical switch (2); the optical signals output by the four optical fiber couplers (3) are respectively input to the optical signal collection end of the spectrometer (7) through the four 1×2Y optical fiber jumpers (4) and the 1×4Y optical fiber jumper (6); The ends of the four optical fiber SPR sensors (5) away from the reflection ends are respectively embedded in one port of the four 1×2Y-type optical fiber jumpers (4); the spectrometer (7) is connected to the microprocessor (9) via a serial communication line; the signal transmission module (12) is connected to the microprocessor (9) via a serial communication line; the control signal input end of the fan (11) is connected to the fan control signal output end of the microprocessor (9); the power supply module (13) is used to provide working power to the light source (1), the optical switch (2), the microprocessor (9) and the signal transmission module (12); the detection The instrument further comprises: a housing (14); four sensor fixing holes (17) are arranged on the side wall of the housing (14); the light source (1), the optical switch (2), four optical fiber couplers (3), four 1×2Y-type optical fiber jumpers (4), four optical fiber SPR sensors (5), a 1×4Y-type optical fiber jumper (6), a spectrometer (7), a microprocessor (9), a power supply module (13) and a signal transmission module (12) are all arranged inside the housing (14); the sensor fixing holes (17) are through holes arranged on the side wall of the housing (14); the four optical fiber SPR sensors (5) pass through the four sensor fixing holes (17). The sensor fixing hole (17) protrudes from and is fixed in the shell (14), and the shell (14) comprises: a bottom partition (15) and a middle partition (16); the bottom partition (15) and the middle partition (16) are parallel to the bottom surface of the shell (14), and divide the internal space of the shell (14) into three areas: an upper layer, a middle layer and a lower layer; the light source (1), the optical switch (2) and the fan (11) are arranged in the lower layer area, the spectrometer (7) and the power supply module (13) are arranged in the middle layer area, and the microprocessor (9) and the signal transmission module (12) are arranged in the upper layer area; Characterized in that the method comprises: A parameter setting step, setting the parameters of the detector; A spectrum collection step, collecting four sets of background light and dark spectrum data through the four optical fiber SPR sensors (5), and transmitting the data to the microprocessor (9) through the spectrometer (7); A buffer data writing step, sending the processing result of the microprocessor (9) to the buffer; a sending judgment step, wherein the terminal selects whether to send the external signal sent by the signal transmission module (12); if sending is selected, the data in the buffer is used as a real-time spectrum through the signal transmission module (12); if not sending is selected, entering a stop judgment step; a stop judgment step, in which the terminal selects whether to stop by using an external signal sent by the signal transmission module (12); if the method is stopped, the method terminates; if the method is not stopped, the method returns to the sending judgment step; The parameter setting steps specifically include: setting the parameters of the baud rate, stop bit and parity bit.

2. The detection method of a miniaturized multi-channel terminal reflective optical fiber SPR detector based on an optical switch according to claim 1, characterized in that: The optical fiber coupler (3) is a SMA905 optical fiber coupler.

3. The detection method of a miniaturized multi-channel terminal reflective optical fiber SPR detector based on an optical switch according to claim 1, characterized in that: The signal transmission module (12) is implemented using a WIFI module.

4. The detection method of a miniaturized multi-channel terminal reflective optical fiber SPR detector based on an optical switch according to claim 1, characterized in that: The four sensor fixing holes (17) are arranged on the side wall of the lower region of the housing (14).

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