阅读说明：本技术 电势扫描局域表面等离子体共振的传感检测装置及方法 (Sensing detection device and method for potential scanning local surface plasma resonance ) 是由 刘清君 陈泽涛 李亚茹 卢妍利 张芬妮 程晨 于 2021-09-13 设计创作，主要内容包括：本发明公开了一种电势扫描局域表面等离子体共振的传感检测装置及方法,所述装置包括：光源；反应池,用于承载待测溶液；扫描电势单元,所述扫描电势单元用于输出扫描电势；激励电极单元,所述激励电极单元的输入端与所述扫描电势单元的输出端电连接,所述激励电极单元的输出端与所述反应池电连接,用于对所述待测溶液产生激励；分光光度计,用于接收由所述光源发出并透过被激励的待测溶液的光线,根据所述光线,得到消光度。所述装置及方法解决了相关技术中存在的传统LSPR传感技术对复合光源依赖的技术问题。(The invention discloses a sensing detection device and a method for potential scanning local surface plasma resonance, wherein the device comprises: a light source; the reaction tank is used for bearing a solution to be tested; a scanning potential unit for outputting a scanning potential; the input end of the excitation electrode unit is electrically connected with the output end of the scanning potential unit, and the output end of the excitation electrode unit is electrically connected with the reaction cell and used for exciting the solution to be detected; and the spectrophotometer is used for receiving the light which is emitted by the light source and penetrates through the excited solution to be measured, and obtaining the extinction degree according to the light. The device and the method solve the technical problem that the traditional LSPR sensing technology depends on a composite light source in the related technology.)

1. A potential scanning localized surface plasmon resonance sensing apparatus, comprising:

a light source;

the reaction tank is used for bearing a solution to be tested;

a scanning potential unit for outputting a scanning potential;

the input end of the excitation electrode unit is electrically connected with the output end of the scanning potential unit, and the output end of the excitation electrode unit is electrically connected with the reaction cell and used for exciting the solution to be detected;

and the spectrophotometer is used for receiving the light which is emitted by the light source and penetrates through the excited solution to be measured, and obtaining the extinction degree according to the light.

2. The apparatus of claim 1, further comprising:

and the output end of the processor is electrically connected with the input end of the scanning potential unit and the input end of the light source and is used for setting the parameters of the scanning potential.

3. The apparatus of claim 1, wherein the excitation electrode unit comprises:

the input end of the working electrode is electrically connected with the output end of the scanning potential unit, and the output end of the working electrode is electrically connected with the reaction cell to excite the solution to be detected;

and the input end of the counter electrode is electrically connected with the output end of the scanning potential unit, and the output end of the counter electrode is electrically connected with the reaction cell to excite the solution to be detected.

4. The device of claim 1, wherein the excitation electrode unit further comprises a reference electrode, an input end of the reference electrode is electrically connected with an output end of the scanning potential unit, and an output end of the reference electrode is electrically connected with the reaction cell to excite the solution to be detected.

5. The apparatus of claim 1, further comprising:

the support comprises a detection platform for bearing the reaction tank, a support wall fixedly connected with the detection platform, a support plate fixedly connected with the support wall and a light ray entrance port fixed on the support plate.

6. The apparatus of claim 2, wherein the light source, the scanning potential unit and the processor are integrated on a same circuit board.

7. The device of claim 6, wherein a battery is mounted on the circuit board and electrically connected to the circuit board for providing power.

8. The device of claim 7, wherein the circuit board further comprises a power management unit, wherein an input of the power management unit is electrically connected to an output of the battery, and wherein an output of the power management unit is electrically connected to the circuit board.

9. The device according to claim 3, wherein a transparent glass substrate is used for the working electrode and the counter electrode so that the light emitted from the light source can be irradiated onto the working electrode and reach the light incident port.

10. A method for the sensored detection of potential-scanned localized surface plasmon resonance, said method being implemented in an apparatus according to any of claims 1-9, the method comprising:

adding a solution to be detected into a reaction tank;

simultaneously turning on a light source and a scanning potential unit to enable the scanning potential unit to output scanning potential to an excitation electrode unit, wherein the excitation electrode unit generates a plasma resonance effect and excites the solution to be detected;

recording the change of the extinction degree along with the change of the scanning potential by a spectrophotometer to obtain a potential-extinction degree relation so as to obtain the type of the electroactive biomolecules in the solution to be detected;

recording the potential-extinction relation of the same electroactive biomolecule under different concentrations of solutions to be detected;

and obtaining the relation between the concentration of the solution to be detected and the extinction degree according to the potential-extinction degree relation under the solutions to be detected with different concentrations so as to realize the sensing detection of the concentration of the solution to be detected of the electroactive biomolecules.

Technical Field

The application relates to the technical field of optical sensing of local surface plasmon resonance, in particular to a sensing detection device and method for potential scanning of local surface plasmon resonance.

Background

Localized Surface Plasmon Resonance (LSPR) is a photon energy resonance absorption phenomenon occurring on nanoparticles such as gold nanospheres or gold nanorods, and the absorption peak intensity and the absorption peak position of LSPR are affected by the composition material, the structural shape, the size, the surface modification and the like of the nanoparticles, and is often applied to the field of biosensing. The LSPR plays an important role in the construction of the optical sensor by virtue of the characteristics of high specific surface area, good size control, excellent ultraviolet-visible spectrum absorption and the like of the gold nanoparticles.

The traditional LSPR sensing technology is to detect the absorption condition of the nano material to incident light under the excitation of a composite light source with a certain range of wavelength, and then judge the refractive index change of the environment where the substance to be detected is located. The sensing technology determines the type of an object to be detected through specific modification of nano particles, judges the concentration of the object to be detected through analyzing the peak change amount of a spectrum, and realizes specific biosensing detection.

In the process of implementing the invention, the inventor finds that at least the following problems exist in the prior art: the traditional LSPR sensing technology has higher requirement on an incident light source, is usually a composite light source based on wavelength scanning, such as an ultraviolet-visible composite light source and the like, has high manufacturing cost and larger occupied space, and cannot adapt to the development of a portable sensing technology.

Disclosure of Invention

The embodiment of the application aims to provide a sensing detection device and a sensing detection method for potential scanning local surface plasmon resonance, so as to solve the technical problem that the traditional LSPR sensing technology depends on a composite light source in the related technology.

According to a first aspect of embodiments of the present application, there is provided a sensing detection apparatus for potential scanning localized surface plasmon resonance, comprising:

a light source;

the reaction tank is used for bearing a solution to be tested;

a scanning potential unit for outputting a scanning potential;

the input end of the excitation electrode unit is electrically connected with the output end of the scanning potential unit, and the output end of the excitation electrode unit is electrically connected with the reaction cell and used for exciting the solution to be detected;

and the spectrophotometer is used for receiving the light which is emitted by the light source and penetrates through the excited solution to be measured, and obtaining the extinction degree according to the light.

Further, the apparatus further comprises:

and the output end of the processor is electrically connected with the input end of the scanning potential unit and the input end of the light source and is used for setting the parameters of the scanning potential.

Further, the excitation electrode unit includes:

the input end of the working electrode is electrically connected with the output end of the scanning potential unit, and the output end of the working electrode is electrically connected with the reaction cell to excite the solution to be detected;

and the input end of the counter electrode is electrically connected with the output end of the scanning potential unit, and the output end of the counter electrode is electrically connected with the reaction cell to excite the solution to be detected.

Further, the excitation electrode unit further comprises a reference electrode, an input end of the reference electrode is electrically connected with an output end of the scanning potential unit, and an output end of the reference electrode is electrically connected with the reaction cell to excite the solution to be detected.

Further, the apparatus further comprises:

the support comprises a detection platform for bearing the reaction tank, a support wall fixedly connected with the detection platform, a support plate fixedly connected with the support wall and a light ray entrance port fixed on the support plate.

Further, the light source, the scanning potential unit and the processor are integrated on the same circuit board.

Furthermore, a battery is mounted on the circuit board, and the battery is electrically connected with the circuit board and used for providing a power supply.

Furthermore, the circuit board further comprises a power management unit, wherein the input end of the power management unit is electrically connected with the output end of the battery, and the output end of the power management unit is electrically connected with the circuit board.

Further, the working electrode and the counter electrode use transparent glass substrates, so that light emitted by the light source can irradiate on the working electrode and reach the light incident port.

According to a second aspect of embodiments of the present application, there is provided a method for sensing potential-scanning localized surface plasmon resonance, the method being implemented in the apparatus according to the first aspect, the method comprising:

adding a solution to be detected into a reaction tank;

simultaneously turning on a light source and a scanning potential unit to enable the scanning potential unit to output scanning potential to an excitation electrode unit, wherein the excitation electrode unit generates a plasma resonance effect and excites the solution to be detected;

recording the change of the extinction degree along with the change of the scanning potential by a spectrophotometer to obtain a potential-extinction degree relation so as to obtain the type of the electroactive biomolecules in the solution to be detected;

recording the potential-extinction relation of the same electroactive biomolecule under different concentrations of solutions to be detected;

and obtaining the relation between the concentration of the solution to be detected and the extinction degree according to the potential-extinction degree relation under the solutions to be detected with different concentrations so as to realize the sensing detection of the concentration of the solution to be detected of the electroactive biomolecules.

The technical scheme provided by the embodiment of the application can have the following beneficial effects:

according to the embodiment, the scanning potential unit adopts a scanning potential excitation technology, so that the requirement of optical sensing on a composite light source based on wavelength scanning is overcome, the problem that the traditional light source occupies a large space is solved, the effect of reducing the volume of the device is achieved, and the effect of reducing the complexity of the optical sensing is also achieved; the excitation electrode unit receives the output of the scanning potential unit and excites the solution to be detected in the reaction tank, the light emitted by the light source penetrates through the solution to be detected and is received by the spectrophotometer to obtain the extinction degree, so that the potential-extinction degree relation is obtained, and the sensing detection of the potential scanning local surface plasma resonance is realized.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

FIG. 1 is a schematic diagram of a potential scanning localized surface plasmon resonance sensing apparatus according to an exemplary embodiment.

FIG. 2 is a representation of an LED light source shown according to an exemplary embodiment.

Fig. 3 is a schematic perspective view of a counter electrode shown in accordance with an exemplary embodiment.

FIG. 4 is a schematic perspective view of a working electrode shown in accordance with an exemplary embodiment.

Fig. 5 is a perspective view of a circuit board shown in accordance with an example embodiment.

Fig. 6 is a top view of a circuit board shown in accordance with an example embodiment.

FIG. 7 is a schematic view of a sensing device holder shown according to an exemplary embodiment.

FIG. 8 is a schematic perspective view of a detection chamber shown according to an exemplary embodiment.

FIG. 9 is a top view of a detection chamber shown according to an exemplary embodiment.

FIG. 10 is a bottom view of a detection chamber shown according to an exemplary embodiment.

FIG. 11 is a schematic view of a cartridge shown according to an exemplary embodiment.

Fig. 12 is a perspective view of a test cassette lid according to an exemplary embodiment.

FIG. 13 is a top view of a test cassette lid shown according to an exemplary embodiment.

FIG. 14 is a bottom view of a test cassette lid shown according to an exemplary embodiment.

FIG. 15 is a schematic perspective view of a cartridge base shown according to an exemplary embodiment.

FIG. 16 is a top view of the base of the cartridge in an embodiment of the present invention.

FIG. 17 is a schematic illustration showing the detachment of a cartridge according to an exemplary embodiment.

FIG. 18 is a system block diagram illustrating a detection device according to an exemplary embodiment.

FIG. 19 is a flowchart illustrating a process for key press events, according to an exemplary embodiment.

FIG. 20 is a graph illustrating potential versus extinction according to an exemplary embodiment.

FIG. 21 is a linear plot of concentration versus extinction, according to an exemplary embodiment.

FIG. 22 is a flow chart illustrating a method for sensing detection of potential-swept localized surface plasmon resonance in accordance with an exemplary embodiment.

The reference numerals in the figures are:

100. a support; 110. a detection table; 120. a stent wall; 130. a mounting plate; 140. a light incident port; 150. an optical fiber splice;

200. a detection cartridge;

210. a detection box base; 211. detecting a box cover fixing opening; 212. detecting a box cover limiting opening; 213. a light source base; 214. a circuit board limiting pile; 215. resetting the key window; 216. a working electrode adjustment window; 217. detecting a base drain gate;

220. a circuit board; 221. a light source; 222. a scanning potential unit; 223. a processor; 224. a digital-to-analog conversion unit; 225. a battery; 226. a power management unit; 227. resetting the key; 228. a detection chamber electrode interface; 229. a circuit board limiting opening;

230. a counter electrode;

240. a detection chamber; 241. a reaction tank; 242. a reference electrode; 243. the circuit board is connected with the contact; 244. the working electrode is connected with the contact; 245. a counter electrode connecting contact; 246. a counter electrode limiting groove; 247. a working electrode limiting groove;

250. a working electrode; 251. a nanocomposite modification region;

260. a detection box cover; 261. detecting a box cover limiting pin; 262. detecting a window; 263. a working electrode presser foot; 264. a detection box cover fixing pin;

300. a spectrophotometer;

400. an optical fiber.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present application. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.

Fig. 1 is a schematic diagram illustrating a sensing apparatus for potential scanning localized surface plasmon resonance according to an exemplary embodiment, as shown in fig. 1, which may include:

a light source 221;

the reaction tank 241 is used for bearing a solution to be tested;

a scanning potential unit 222, the scanning potential unit 222 being configured to output a scanning potential;

the input end of the excitation electrode unit is electrically connected with the output end of the scanning potential unit 222, and the output end of the excitation electrode unit is electrically connected with the reaction cell 241 and used for exciting the solution to be detected;

the spectrophotometer 300 is configured to receive light emitted by the light source 221 and transmitted through the excited solution to be measured, and obtain an extinction degree according to the light.

As can be seen from the above embodiments, the scanning potential unit 222 described in the present application adopts a scanning potential excitation technology, and overcomes the requirement of optical sensing on the wavelength scanning-based composite light source 221, so that the light source 221 overcomes the problem of large occupied space of the conventional light source 221, and achieves the effect of reducing the device volume and the effect of reducing the complexity of optical sensing; the excitation electrode unit receives the output of the scanning potential unit 222 and excites the solution to be detected in the reaction tank 241, and the light emitted by the light source 221 penetrates through the solution to be detected and is received by the spectrophotometer 300 to obtain the extinction degree, so that the potential-extinction degree relation is obtained, and the sensing detection of the potential scanning local surface plasmon resonance is further realized.

In an embodiment, the light source 221 is an LED lamp bead with a specific light emitting wavelength, and the power consumption of the LED lamp bead is not greater than 110 mW. As shown in fig. 2, the LED light source 221 of the photostimulation unit is characterized by the spectrophotometer 300, and it can be seen from the graph that at 710nm, the LED lamp shows a distinct peak, which indicates that the LED lamp has better monochromaticity. The LED lamp beads can be near-infrared lamp beads with the light-emitting wavelength of 710nm, are used for being matched with the wavelength of the characteristic peak of the modified gold nanorod on the excitation electrode unit, and can improve the sensitivity of the potential scanning local surface plasma resonance sensing detection to the greatest extent.

In one embodiment, the scan potential unit 222 may provide an output of a scan potential, the output range of the scan potential is not narrower than 0V-0.6V, the output step-up interval is not more than 0.1mV, and the output time interval is not more than 1ms, and specifically, the scan potential unit 222 includes a voltage stabilizing circuit for providing a stable output of the scan potential, wherein the output range of the scan potential is not narrower than 0V-0.6V so as to correspond to the linear range of the nanomaterial under potential regulation, the step-up interval is not more than 0.1mV, and the output time interval is not more than 1ms, which can improve the detection resolution and the specificity detection capability.

Specifically, the excitation electrode unit comprises a working electrode 250 and a counter electrode 230, an input end of the working electrode 250 is electrically connected with an output end of the scanning potential unit 222, and an output end of the working electrode 250 is electrically connected with the reaction cell 241 to generate excitation on the solution to be detected; the input end of the counter electrode 230 is electrically connected with the output end of the scanning potential unit 222, the output end of the counter electrode 230 is electrically connected with the reaction cell 241 to generate excitation to the solution to be detected, the excitation is applied to the solution of the electroactive molecules to be detected in the form of scanning potential, the electroactive molecules are catalyzed to be oxidized and electrons are released to act on potential scanning local surface plasmon resonance, and then biosensing application is realized.

Further, the working electrode 250 and the counter electrode 230 use a transparent glass substrate so that the light emitted from the light source 221 can be irradiated onto the working electrode 250 and reach the light incident port 140.

Specifically, the counter electrode 230 and the working electrode 250 are shaped as shown in fig. 3, and the working electrode 250 and the counter electrode 230 may be made of indium tin oxide, which is based on chemical stability and good conductivity of indium tin oxide, so as to realize stable construction of the working electrode 250 and the counter electrode 230.

Further, as shown in fig. 4, the working electrode 250 includes a nanocomposite modification region 251 for modification of the working electrode 250 and for implementing localized surface plasmon resonance applications. In one embodiment, the nanocomposite modification region 251 is located in a central region of the working electrode 250 so as to completely cover the reaction cell 241.

Specifically, the modification process of the working electrode 250 includes: synthesizing gold nanorods by adopting a seed growth method; coating a layer of conductive polymer polyaniline on the surface of the gold nanorod by adopting an oxidative polymerization method; and carrying out surface plasma treatment on the indium tin oxide electrode, and uniformly depositing the polyaniline-coated gold nanorods on the surface of the indium tin oxide electrode in a spraying manner so as to realize stable and enhanced local surface plasma resonance detection.

Further, the excitation electrode unit further includes a reference electrode 242, an input end of the reference electrode 242 is electrically connected to an output end of the scanning potential unit 222, and an output end of the reference electrode 242 is electrically connected to the reaction cell 241 to excite the solution to be detected.

Specifically, the reference electrode 242 may employ a silver/silver chloride electrode for outputting a stable scanning potential excitation signal.

Specifically, the silver/silver chloride electrode can be prepared by an electrolytic method, and the preparation method comprises the following steps:

(1) carrying out surface pretreatment on the silver wire electrode with the purity of 99.99%, wherein the surface pretreatment comprises surface sulfide removal, oil removal and the like;

(2) taking a platinum electrode as an auxiliary electrode, connecting the platinum electrode with a negative electrode of a power supply, and connecting a pretreated silver wire electrode with a positive electrode of the power supply;

(3) putting a silver wire electrode and a platinum electrode in an HCl solution with the concentration of 1mol/L at 25 ℃, switching on a direct current of 4mA for 3h, and continuously shaking the silver wire in the chlorination process to ensure uniform chlorination.

Further, the device may further include a detection chamber 240, the detection chamber 240 is configured to be electrically connected to the circuit board 220 and perform a sensing experiment, the detection chamber 240 includes the reaction cell 241, the reference electrode 242 is embedded in the reaction cell 241, and a three-electrode system is configured with the working electrode 250 and the counter electrode 230 to realize application of a scanning potential.

Specifically, the size of the detection cavity 240 is not greater than 9mm in length, 9mm in width and 2mm in depth, so that a small amount of the substance to be detected is consumed in the detection process.

Specifically, the detection chamber 240 further includes a circuit board connection contact 243, a working electrode connection contact 244 and a counter electrode connection contact 245, and the circuit board connection contact 243 is electrically connected to the reference electrode 242, the working electrode connection contact 244 and the counter electrode connection contact 245 in an internal wiring manner. In specific implementation, the detection cavity 240 is provided with a contour by a 3D printing technology, and the internal wiring of the detection cavity 240 is realized by means of lead wire embedding and contact welding, so as to achieve the effects of simplification and anti-interference of the device.

Specifically, the detection cavity 240 further comprises a counter electrode limiting groove 246 and a working electrode limiting groove 247, the counter electrode 230 can be adhered to the counter electrode limiting groove 246 through waterproof glue, and the working electrode 250 is fixed on the detection cavity 240 through the working electrode limiting groove 247. Specifically, the counter electrode limiting groove 246 and the working electrode limiting groove 247 may achieve an effect of simplifying electrode assembly.

Specifically, the device further comprises a processor 223, wherein an output end of the processor 223 is electrically connected with an input end of the scanning potential unit 222 and an input end of the light source 221, and is used for setting parameters of the scanning potential, and the parameters comprise an output range interval, an output boosting interval and an output time interval. In one embodiment, the processor 223 may include an MSP430FR2111RLL chip. Specifically, the MSP430FR2111RLL chip has a 3.75KB program FRAM, 1KB RAM, and is sized to be 3mm long by 3mm wide by 0.8mm high, can provide 16MHz of frequency for fast instruction execution performance, and has an optimized low power mode to accommodate portable battery 225 powered applications.

Further, the light source 221, the scanning potential unit 222 and the processor 223 are integrated on the same circuit board 220 to achieve a miniaturized design of the device.

Further, as shown in fig. 5 and 6, the circuit board 220 may further include a digital-to-analog conversion unit 224, and the scanning potential is output after high-precision conversion processing from a digital signal to an analog signal by the digital-to-analog conversion unit 224. In one embodiment, the digital-to-analog conversion unit 224 is implemented by a chip DAC80502 to perform 16-bit high-precision digital-to-analog conversion.

Further, as shown in fig. 3 and 4, a battery 225 is mounted on the circuit board 220, the battery 225 is electrically connected to the circuit board 220 for providing a power supply, and in an embodiment, the battery 225 unit is composed of a button battery 225 providing a 3V standard voltage and a base thereof.

Further, as shown in fig. 3 and fig. 4, the circuit board 220 further includes a power management unit 226, an input end of the power management unit 226 is electrically connected to an output end of the battery 225, and an output end of the power management unit 226 is electrically connected to the circuit board 220, and is configured to adjust voltage to meet different requirements of each chip inside the circuit board 220 for voltage. Specifically, in an embodiment, the power management unit 226 may include a power management chip TPS63900, the TPS63900 power management chip may realize stable adjustment of output voltage in a range from 1.8V to 5V, the TPS63900 power management chip converts 3V direct current into 3.3V for supplying power to the processor 223, and converts 3V direct current into 5V for supplying power to the light source 221.

In one embodiment, as shown in fig. 3 and 4, the circuit board 220 further includes a reset key 227, and the reset key 227 is used for sequentially completing the whole processes of power on, light source 221 on, potential output, light source 221 off and power off by a single key, so as to simplify the sensing process.

In one embodiment, as shown in fig. 3 and 4, the circuit board 220 further includes a detection chamber electrode interface 228 for connecting with a circuit board connecting contact 243 on the detection chamber 240 to achieve contact electrical connection of the working electrode 250, the counter electrode 230 and the reference electrode 242 during the detection process, without additional fixing operations, so as to simplify the assembly process of the detection chamber 240 and the circuit board 220.

Specifically, as shown in fig. 7, the apparatus further includes a support 100, where the support 100 includes a detection platform 110 for bearing a reaction cell 241, a support wall 120 fixedly connected to the detection platform 110, a support plate 130 fixedly connected to the support wall 120, and a light incident port 140 and an optical fiber connector 150 fixed on the support plate 130, where the light incident port 140 is perpendicular to a plane where the detection platform 110 is located, so that light emitted from the detection box 200 can be captured more smoothly, and the optical fiber connector 150 is connected to the spectrophotometer 300 through an optical fiber 400, so as to implement detection of extinction degree.

Further, as shown in fig. 8-10, the device may further include a detection chamber 240, the detection chamber 240 includes the reaction cell 241, the reference electrode 242 is embedded in the reaction cell 241, and a three-electrode system is constructed with the working electrode 250 and the counter electrode 230 to realize the application of the scanning potential.

In one embodiment, the device further comprises a detection box 200 for fixing the circuit board 220 and the detection cavity 240, and the detection box 200 has an outer volume not larger than 66mm in length, 46mm in width and 19mm in height, so as to realize miniaturization and portability of the sensing device.

Specifically, as shown in fig. 11 to 16, the detecting box 200 includes a detecting box cover 260 and a detecting box base 210, the detecting box cover 260 includes a detecting box cover fixing foot 264 and a detecting box cover limiting foot 261, the detecting box base 210 includes a detecting box cover fixing opening 211 and a detecting box cover limiting opening 212, wherein the detecting box cover 260 is fixed on the detecting box base 210 through the detecting box cover fixing foot 264 and the detecting box cover fixing opening 211, and the movable range of the detecting box cover 260 is limited through the detecting box cover limiting foot 261 and the detecting box cover limiting opening 212;

further, the detecting box cover 260 further includes a detecting window 262 for passing through the detection signal and a working electrode presser foot 263 for fixing the working electrode 250.

Further, the detection box base 210 further includes a light source base 213 for carrying the light source 221, a circuit board positioning post 214 for mating with the circuit board positioning hole 229 to fix the circuit board 220, a reset button window 215 for passing through the reset button 227, a working electrode adjustment window 216 for adjusting the position of the working electrode 250, and a detection base drain grid 217 for ventilation and heat dissipation.

In one possible implementation manner, as shown in fig. 17, the excitation electrode unit, the detection cavity 240 and the circuit board 220 may be integrated in the detection box 200, the circuit board 220 is fixed on the detection box base 210, the working electrode 250 in the excitation electrode unit is fixed on the upper surface of the detection cavity 240, the counter electrode 230 in the excitation electrode unit is fixed on the lower surface of the detection cavity 240, and the detection cavity 240 is fixed on the upper portion of the circuit board 220 and electrically connected. The test cassette 200 is prevented from being placed on the test stage 110 of the rack 100, the light entrance port 140 of the rack 100 is aligned with the test window 262 of the test cassette cover 260, and the spectrophotometer 300 is connected to the optical fiber connector 150 of the rack 100 through the optical fiber 400 to receive the light passing through the light entrance port 140 and obtain the extinction degree.

In one possible implementation, the response after pressing the reset key 227 is shown in fig. 18, and first the signal is transmitted from the key to the processor 223, the light source 221 is controlled to be turned on to complete the detection of the spectrum, the scanning potential unit 222 is controlled to generate the step scanning potential, and the step scanning potential is output after passing through the digital-to-analog signal conversion unit to complete the detection of the potential scanning local surface plasmon resonance.

In one possible implementation, the process of the potential scanning localized surface plasmon resonance detection is shown in fig. 19, and the processor 223 sets parameters of the output scanning potential and controls the potentiostat to generate the output scanning potential according to the parameters, and simultaneously turns on the light source 221 for optical excitation; in the process of outputting the scanning potential, it is detected whether the output of the potential is completed, if not, the output is continued, and if completed, the light source 221 is turned off, and the detection process is ended.

The embodiment of the invention takes typical electroactive biomolecule uric acid as an example to explain the sensing process of potential scanning local surface plasmon resonance, and the experimental steps are as follows:

(1) using 0.01mol/L phosphate buffer solution as a solvent, and respectively preparing uric acid solutions with the concentrations of 20 mu mol/L, 40 mu mol/L, 60 mu mol/L, 80 mu mol/L and 100 mu mol/L as solutions to be detected;

(2) detecting and applying by using the potential scanning local surface plasma resonance sensing device through a polyaniline-coated gold nanorod modified indium tin oxide electrode;

(3) the above solutions of the analyte were sequentially added to the reaction cell 241251, and the change in the spectral intensity with the applied potential was recorded while the reset button 227 was pressed.

Further, the sensing mechanism of potential scanning localized surface plasmon resonance can be described as:

the free electron distribution on the surface of the gold nanorod is changed under the influence of electrochemical signals such as applied potential, and the resonance absorption peak of the local surface plasma resonance is changed along with the change of the applied potential on the gold nanorod by combining the characteristic that the resonance absorption peak displacement of the local surface plasma resonance is influenced by the electron distribution on the surface of the gold nanorod. When a linear scanning potential is applied to the gold nanorod, the change of a resonance absorption peak at a certain wavelength is linear within a certain range, namely the potential scans the local surface plasmon resonance, and the result is shown by a potential-extinction spectrum. Based on the above, when external signals such as electric signals generated in the electrochemical oxidation-reduction process of the electroactive biomolecules act on the potential scanning local surface plasma resonance, the potential-extinction spectrum of the electroactive biomolecules correspondingly changes, and the change can reflect the oxidation-reduction potential and the concentration attribute of the molecules subjected to the electrochemical oxidation-reduction reaction, so that the specific detection of the object to be detected is realized.

Further, taking electroactive biomolecule uric acid as an example, the sensing mechanism of potential scanning local surface plasmon resonance can be described as follows:

when electroactive molecule uric acid exists in the reaction cell 241, uric acid undergoes an oxidation reaction in the process of applying a scanning potential, and electron transfer occurs, and particularly when the scanning potential reaches 0.35V (i.e., the oxidation potential of uric acid), the amount of electrons released by uric acid oxidation reaches the maximum, and at this time, the influence on the electron density on the surface of the nanocomposite is also the maximum, which is shown in the increase of extinction at 0.35V, i.e., the oxidation potential, on the potential-extinction spectrum. Because different electric active biological molecules have different oxidation potentials, the type, namely the specificity, of the object to be detected can be judged according to the detected extinction degree lifting point.

The results of the above sensing detection experiment of potential scanning localized surface plasmon resonance are as follows:

as shown in fig. 20, as the uric acid concentration increases, the amount of change in the potential-extinction spectrum becomes correspondingly larger. The result shows that the electron quantity of uric acid oxidation transfer is correspondingly increased along with the increase of the concentration of uric acid, and the influence of the electron quantity on the indium tin oxide electrode modified by the polyaniline-coated gold nanorod is also increased, namely the extinction degree is increased. Fig. 21 shows the change of extinction at the oxidation potential of uric acid of 0.35V, and it can be seen that the change of extinction with the increase of uric acid concentration has an approximately linear relationship with uric acid concentration. Therefore, the sensing device and the method for potential scanning local surface plasmon resonance can realize the detection of the electroactive biomolecules such as uric acid.

The working principle of the sensing detection device for potential scanning local surface plasmon resonance provided by the invention is as follows:

the cartridge 200 is placed on the test table 110 of the cradle 100, and the reset button 227 is pressed. At this point the device is powered on and the processor 223 controls the LED lamp to light up and set the scanning potential output parameter. Under the excitation of the LED lamp, the modified nanocomposite on the working electrode 250 exhibits a localized surface plasmon resonance phenomenon. Under the action of the scanning potential, the localized surface plasmon resonance phenomenon exhibited by the modified nanocomposite on the working electrode 250 shows a linear variation trend, i.e., a potential-extinction spectrum is formed. Meanwhile, under the excitation of scanning potential, the solution to be detected is electrochemically oxidized to generate electron transfer, the electron transfer acts on potential scanning local surface plasma resonance, so that the potential-extinction spectrum of the potential-scanning local surface plasma resonance is correspondingly changed, the change condition of the extinction degree along with the scanning potential is detected by the spectrophotometer 300, the type and concentration information of the solution to be detected is obtained, and the sensing detection application of the device is further realized.

FIG. 22 is a flow chart illustrating a method for sensing detection of potential-swept localized surface plasmon resonance in accordance with an exemplary embodiment. Referring to fig. 22, the method includes:

step S11: adding the solution to be detected into a reaction tank 241;

step S12: simultaneously turning on a light source 221 and a scanning potential unit 222 to enable the scanning potential unit 222 to output scanning potential to an excitation electrode unit, wherein the excitation electrode unit generates a plasma resonance effect and excites the solution to be detected;

step S13: recording the change of the extinction degree along with the change of the scanning potential by using a spectrophotometer 300 to obtain a potential-extinction degree relation so as to obtain the type of the electroactive biomolecules in the solution to be detected;

step S14: recording the potential-extinction relation of the same electroactive biomolecule under different concentrations of solutions to be detected;

step S15: and obtaining the relation between the concentration of the solution to be detected and the extinction degree according to the potential-extinction degree relation under the solutions to be detected with different concentrations so as to realize the sensing detection of the concentration of the solution to be detected of the electroactive biomolecules.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.