CN112505121A

CN112505121A - Anti-interference photoelectrochemical disease marker sensor and preparation method and application thereof

Info

Publication number: CN112505121A
Application number: CN202011460664.8A
Authority: CN
Inventors: 范高超; 钦威; 穆飞飞
Original assignee: Jiangsu Zhizhi Biotechnology Co ltd
Current assignee: Jiangsu Zhizhi Biotechnology Co ltd
Priority date: 2020-12-11
Filing date: 2020-12-11
Publication date: 2021-03-16
Anticipated expiration: 2040-12-11
Also published as: CN112505121B

Abstract

The invention discloses an anti-interference photoelectrochemical disease marker sensor constructed based on polyethylene glycol and a preparation method and application thereof, belonging to the technical field of photoelectrochemical biosensors. The disease marker sensor is prepared by successively modifying a capture antibody Ab and polyethylene glycol PEG corresponding to a disease marker on a photocathode, and detecting a target disease marker by utilizing the change of a photocurrent signal caused by the blocking effect of the obvious steric hindrance effect of the disease marker Ag on the charge transfer of the sensor. The invention can realize high sensitivity to the detection of the target disease marker, can accurately detect the target disease marker even in a serum sample, has the potential of resisting the nonspecific adsorption of biological macromolecules such as protein and the like, and has very important significance to the in vitro accurate diagnosis of diseases.

Description

Anti-interference photoelectrochemical disease marker sensor and preparation method and application thereof

Technical Field

The invention belongs to the technical field of photoelectrochemical biosensors, and particularly relates to an anti-interference photoelectrochemical disease marker sensor constructed based on polyethylene glycol and a preparation method and application thereof.

Background

With the intensive development of research in the fields of molecular biology, genomics, proteomics and the like, a plurality of biomarkers related to major diseases are discovered. The disease markers are accurately and rapidly detected, the development state of the disease can be reflected in time, scientific basis is provided for the diagnosis of the disease, and meanwhile, the method has important significance in early warning and clinical treatment of a plurality of typical diseases. The biosensor is an important mode for in vitro diagnosis of major diseases, and is an analysis and detection device mainly composed of a signal conversion element and a molecular recognition element. The photoelectrochemical biosensing is a new generation sensing technology developed by combining a photoelectrochemical technology on the basis of the traditional electrochemical analysis method. The electrochemical biosensor not only inherits the advantages of simple device, convenient operation, low cost and easy miniaturization of the electrochemical biosensor, but also has the characteristics of low background signal and higher sensitivity. In addition, the photoelectrochemistry biosensing can realize self-energy supply of the system, and is easier to realize rapid real-time field detection.

The photoelectrochemical biosensor can be classified into photo anode sensing and photo cathode sensing according to sensing categories. Although the photocurrent output signal sensed by the photoanode is obvious and the sensitivity is also high, the electron donor oxidation reaction occurs at the anode interface, and multi-component reducing species such as glutathione, dopamine, cysteine, ascorbic acid and the like which potentially coexist in an actual biological sample have certain interference on the accuracy of a detection result. On the contrary, an electron acceptor reduction reaction occurs on the sensing interface of the photocathode, and potentially coexisting multi-component reducing species cannot interfere with a real detection signal, so that the photocathode has excellent anti-reducing species interference capability, and the cathode photoelectrochemistry biosensing has the potential of accurate detection in actual complex biological samples.

It is known that the chemical composition of normal human blood is very complex, and contains many biological macromolecules such as proteins besides multi-component potentially reductive species. When the sensor incubates a target detection object in blood, the biomacromolecules in the blood are also easily nonspecifically adsorbed to the surface of the sensing electrode, and interference is generated on a sensing system, so that the accuracy of the detection result of the sensor is not ideal. However, there are only few reports on cathode photoelectrochemical biosensors that resist interference of biomacromolecules such as proteins.

Considering that polyethylene glycol (PEG) is a non-toxic polymer with high hydrophilicity and good biocompatibility, relevant data have demonstrated that an interface modified by PEG can effectively reduce the nonspecific adsorption of biological macromolecules such as proteins on the surface of an electrode, and polyethylene glycol has been recognized as the "gold standard" in anti-pollution polymers. However, the application of the cathode photoelectrochemical biosensor constructed based on PEG in resisting the interference of potential reducing species in an actual biological sample and the nonspecific adsorption of biological macromolecules such as proteins is not reported at present, so that the development of the anti-interference photoelectrochemical biosensor constructed based on PEG with strong anti-interference performance and high sensitivity has the capability of resisting the interference of the potential reducing species in the actual biological sample, also has the potential of resisting the nonspecific adsorption of the biological macromolecules such as proteins, and has very important significance for the precise diagnosis of diseases in vitro.

Disclosure of Invention

In view of the above, the present invention aims to provide an anti-interference photoelectrochemical disease marker sensor which has high sensitivity and is constructed based on polyethylene glycol, and a preparation method and an application thereof, aiming at the problems in the prior art, the anti-interference photoelectrochemical disease marker sensor not only has high sensitivity to a target disease marker, but also can accurately detect the target disease marker even in a serum sample, and also has the potential of resisting nonspecific adsorption of biological macromolecules such as proteins, and the anti-interference photoelectrochemical disease marker sensor has very important significance for accurate diagnosis in vitro of diseases.

In order to achieve the purpose, the technical scheme of the invention is as follows:

in a first aspect, the invention provides an anti-interference photoelectrochemical disease marker sensor, which is prepared by successively modifying a capture antibody Ab and polyethylene glycol PEG corresponding to a disease marker on a photocathode, and detecting the target disease marker by utilizing the change of a photocurrent signal caused by the blocking effect of the obvious steric hindrance effect of the target disease marker Ag on the charge transfer of the sensor. .

Wherein the photocathode is CuInS₂/ZnIn₂S₄Photocathode of said CuInS₂/ZnIn₂S₄The photocathode is a P-type semiconductor material CuInS₂As a photocathode substrate, modifying a sensitizer ZnIn on the surface of the substrate₂S₄And obtaining the compound.

Wherein the capture antibody Ab is a PSA capture antibody Ab.

In a second aspect, the invention provides a method for preparing an anti-interference photoelectrochemical disease marker sensor, which comprises the following specific steps:

(1) preparation of CuInS₂/ZnIn₂S₄A photocathode: using P-type semiconductor material CuInS₂As a photocathode substrate, modifying a sensitizer ZnIn on the surface of the substrate₂S₄Preparation of CuInS₂/ZnIn₂S₄A photocathode;

(2) sequentially anchoring a PSA capture antibody Ab and polyethylene glycol PEG to the CuInS prepared in the step (1)₂/ZnIn₂S₄And (4) a photocathode, namely the anti-interference photoelectrochemical disease marker sensor is prepared.

Wherein in the step (1), CuCl is adopted as CuCl by a hydrothermal method₂、InCl₃And CH₃CSNH₂Respectively as a Cu source, an In source and an S source, and directly growing CuInS on the FTO conductive glass₂Nano film to obtain CuInS₂A photocathode substrate; mixing the CuInS₂The photocathode substrate is sequentially immersed in Zn (NO)₃)₂、Na₂S、InCl₃And Na₂In the S solution, the CuInS is obtained by deposition and calcination through continuous ion layer adsorption and reaction method₂/ZnIn₂S₄A photocathode.

Further, preparing the CuInS₂The molar ratio of the Cu source, the In source and the S source of the photocathode substrate is 2: 5: 15, the concentration of the Cu source is 4-20 mM, and the reaction temperature is 180 ℃; deposition of ZnIn₂S₄The number of adsorption and reaction cycles of the ion layer is 3-5.

Wherein in the step (2), CuInS is adopted₂/ZnIn₂S₄Dripping chitosan and glutaraldehyde solution on the photocathode successively; then, dripping a capture antibody Ab, and incubating at low temperature; then, PEG modified by amino is dripped to construct an anti-pollution interface, and the anti-interference photoelectrochemical disease is finally obtained after room temperature incubationA marker sensor.

Further, the concentration of the capture antibody Ab incubated at low temperature is 50-250 mug/mL, the molecular weight of the PEG is not less than 2000, and the concentration of the PEG incubated at room temperature is 1-4 mg/mL.

In a third aspect, the invention provides an application of an anti-interference photoelectrochemical disease marker sensor in an in vitro detection product.

Compared with the prior art, the invention has the following beneficial effects:

1) the disease marker sensor disclosed by the invention has the remarkable characteristics of simple device, low cost, convenience in operation, low background signal and system self-energy supply, and meanwhile, the anti-interference capability of the sensor is remarkably improved by utilizing the excellent capability of the polyethylene glycol on an anti-biomacromolecule pollution sensing interface.

2) The anti-interference photoelectrochemical disease marker sensor constructed based on the polyethylene glycol has the advantages of simple and convenient preparation process, no need of purification, convenience and rapidness for detecting the target disease marker, and the photoelectrochemical sensor has the application potential of accurately and sensitively detecting the target disease marker in an actual biological sample, and is suitable for popularization and application in the market.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 shows CuInS corresponding to Cu sources with different concentrations in example 1 of the present invention₂Photocurrent response graph of the photocathode substrate.

FIG. 2 shows different ZnIns in example 1 of the present invention₂S₄And the photo-current response graph of the photocathode corresponding to the cycle number.

Fig. 3 is a graph of photocurrent response of Ab-modified electrodes at different Ab incubation concentrations in example 1 of the present invention.

FIG. 4 is CuInS in example 2 of the present invention₂Scanning electron microscopy of photocathode substrates.

FIG. 5 is CuInS in example 3 of the present invention₂/ZnIn₂S₄Scanning electron microscopy of photocathodes.

FIG. 6 is CuInS in example 3 of the present invention₂/ZnIn₂S₄X-ray diffraction pattern of photocathode.

Fig. 7 is a photocurrent response diagram of a disease marker sensor preparation process in example 5 of the present invention.

FIG. 8 is a standard graph of disease marker sensor versus PSA detection as described in example 6 of the present invention.

FIG. 9 is a fluorescence view of nonspecific adsorption of proteins by a disease marker sensor in example 7 of the present invention.

FIG. 10 is a graph showing the photocurrent signal of the disease marker sensor in example 8 of the present invention in serum versus PSA detection.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the specification of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Optimization of detection conditions

1、CuCl₂Concentration of the solution

Due to CuInS₂/ZnIn₂S₄The photocurrent response value of the photocathode has significant influence on the detection sensitivity of the finally prepared anti-interference photoelectrochemical disease marker sensor, so the following method has obvious influence on CuInS₂/ZnIn₂S₄The preparation process parameters of the photocathode are optimized:

due to CuInS₂The deposition amount on the electrode can be adjusted by the precursor concentration, and the mol of the Cu source, the In source and the S source of the fixed precursorsThe ratio is 2: 5: 15, optimizing the concentration of the precursor Cu source, specifically as follows:

growing CuInS on FTO conductive glass by adopting hydrothermal method₂And (4) a nano film. With CuCl₂、InCl₃And CH₃CSNH₂Respectively serving as a Cu source, an In source and an S source, and fixing the molar ratio of the Cu source to the In source to the S source to be 2: 5: 15, CuCl₂The concentrations of the solutions are respectively 4mM, 8mM, 12mM, 16mM and 20mM, the solutions are dissolved in absolute ethyl alcohol, stirred for 30min to prepare precursor solutions, and the precursor solutions are transferred into a reaction kettle. Placing the FTO conductive glass into a reaction kettle, reacting for 8h at 180 ℃, cooling, taking out the FTO conductive glass, cleaning the surface residues with deionized water, and drying for 2h at 80 ℃ to obtain CuInS₂A photocathode substrate.

By performing photocurrent characterization tests, as shown in FIG. 1, it can be seen that when CuCl is used₂At a concentration of 12mM, CuInS₂The photocurrent response of the photocathode substrate was optimized, so 12mM CuCl was selected₂As CuInS₂Optimal preparation process parameters of the photocathode substrate.

2、ZnIn₂S₄Number of cycles of adsorption and reaction of ionic layer

Due to ZnIn₂S₄Nanocrystalline in CuInS₂The deposition amount on the photocathode substrate can be adjusted by the cycle number of adsorption and reaction of the ion layer, so that the following pair of ZnIn₂S₄The cycle times of the adsorption and reaction of the ion layer in the deposition process are optimized, and the method specifically comprises the following steps:

ZnIn is modified by adopting a continuous ion layer adsorption and reaction method₂S₄. Mixing CuInS₂The photocathode substrate is sequentially immersed in 0.1M Zn (NO)₃)₂Methanol solution, 0.1M Na₂S methanol/Water Mixed solution (volume ratio 1/1), 0.1M InCl₃Methanol solution, 0.1M Na₂And (2) soaking the S methanol/water mixed solution (with the volume ratio of 1/1) for 100S each time, cleaning the electrode with the methanol solution after each soaking step, respectively repeating the steps for 1 time, 2 times, 3 times, 4 times, 5 times and 6 times, calcining for 1 hour in the air atmosphere at 180 ℃, and naturally cooling to room temperature to obtain the CuInS₂/ZnIn₂S₄Light and shadeAnd (4) a pole.

It can be obtained by performing photocurrent characterization test, as shown in FIG. 2, from which it can be seen that ZnIn₂S₄When the cycle times of adsorption and reaction of the nanocrystalline ion layer is 4 times, CuInS₂/ZnIn₂S₄The photocurrent response of the photocathode is optimized, and thus ZnIn is selected₂S₄The cycle times of the ionic layer adsorption and reaction are 4 times, which is the best preparation process parameter.

3、Incubation concentration of PSA Capture antibody Ab

Capture of antibody Ab by PSA on sensing electrodeIncubation concentrationAnd the quantitative detection range of the finally prepared anti-interference photoelectrochemical disease marker sensor is obviously influenced, so that the preparation process parameters of the modified Ab are optimized:

and due to Ab on the sensing electrodeIncubation concentrationSince the Ab can be expressed by the incubation concentration on the electrode, the incubation concentration of Ab is optimized as follows:

in the optimized CuInS₂/ZnIn₂S₄Dripping 20 mu L of chitosan solution with the mass fraction of 0.08 percent on the photocathode, and drying at 40 ℃; washing the electrode with 60mM NaOH and deionized water for several times, dripping 25 μ L of glutaraldehyde solution with mass fraction of 5% to the electrode, and standing at room temperature for 30 min; after the electrode was washed with deionized water, 20. mu.L of PSA capture antibody Ab at concentrations of 50. mu.g/mL, 100. mu.g/mL, 150. mu.g/mL, 200. mu.g/mL, and 250. mu.g/mL, respectively, was dropped onto the electrode, and after overnight incubation at 4 ℃, the electrode was washed with a phosphate buffer (pH 7.4, 10mM) to obtain an Ab-modified electrode.

As shown in FIG. 3, the incubation concentration of Ab needs to be greater than or equal to 100 μ g/mL to ensure sufficient immobilization of Ab on the sensing electrode for obtaining the optimal quantitative detection range, so that Ab greater than or equal to 100 μ g/mL is selected as the optimal incubation concentration.

Example 2

CuInS₂Preparation of photocathode substrate

With 12mM CuCl₂、30mM InCl₃And 90mMCH₃CSNH₂Respectively serving as a Cu source, an In source and an S source, dissolving In absolute ethyl alcohol, stirring for 30min to prepare a precursor solution, and transferring into a reaction kettle. Placing the FTO conductive glass into a reaction kettle, reacting for 8h at 180 ℃, cooling, taking out the FTO conductive glass, cleaning the surface residues with deionized water, and drying for 2h at 80 ℃ to obtain CuInS₂A photocathode substrate.

Scanning Electron microscope As shown in FIG. 4, it can be seen that CuInS₂The nano film is a three-dimensional porous structure consisting of a large number of nano sheets with smooth surfaces and the thickness of about 15-20 nm.

Example 3

CuInS₂/ZnIn₂S₄Preparation of photocathode

The CuInS prepared in example 2 was mixed₂The photocathode substrate is sequentially immersed in 0.1M Zn (NO)₃)₂Methanol solution, 0.1M Na₂S methanol/Water Mixed solution (volume ratio 1/1), 0.1M InCl₃Methanol solution, 0.1M Na₂And (2) soaking the S methanol/water mixed solution (with the volume ratio of 1/1) for 100S each time, cleaning the electrode with the methanol solution, circularly repeating for 4 times, calcining for 1h in air atmosphere at 180 ℃, and naturally cooling to room temperature to obtain the CuInS₂/ZnIn₂S₄A photocathode.

The scanning electron microscope is shown in FIG. 5, from which it can be seen that ZnIn₂S₄The nano-crystalline size is about 10-15nm and is relatively uniformly distributed in the CuInS₂Surface of the nano-film shows ZnIn₂S₄Nanocrystalline in CuInS₂Successfully deposited on the photocathode.

And the CuInS₂/ZnIn₂S₄The X-ray diffraction pattern of the photocathode is shown in FIG. 6, from which CuInS can be seen₂Characteristic diffraction peaks of (a) at 2 θ of 28.24 °, 32.68 °, 55.36 ° and 57.98 °, respectively correspond to pure CuInS₂Crystal planes (112), (200), (215) and (224) of phase (PDF No. 38-0777); ZnIn₂S₄The characteristic diffraction peaks of (A) correspond to pure ZnIn at 2 theta of 21.58 degrees, 28.87 degrees, 30.44 degrees, 32.37 degrees, 39.77 degrees, 47.17 degrees, 42.21 degrees and 55.58 degrees respectively₂S₄Crystals of phase (PDF No.72-0773)Faces (006), (103), (104), (105), (108), (110), (1012), and (202), thus demonstrating CuInS₂/ZnIn₂S₄Photocathodes were successfully prepared.

Example 4

Preparation of anti-interference photoelectrochemical disease marker sensor

CuInS prepared in example 3₂/ZnIn₂S₄Dripping 20 μ L of 0.08% chitosan solution on a photocathode, drying at 40 deg.C, washing the electrode with 60mM NaOH and deionized water for several times, dripping 25 μ L of 5% glutaraldehyde solution on the electrode, standing at room temperature for 30min, and washing the electrode with deionized water.

And then 20 mu L of 100 mu g/mL PSA capture antibody Ab is dripped on the electrode, after overnight incubation at 4 ℃, the electrode is cleaned by phosphate buffer (pH 7.4, 10mM), 20 mu L of 2mg/mL PEG-2000 solution is dripped to construct an anti-pollution interface, and the anti-interference photoelectrochemical disease marker sensor is constructed after incubation for 4 hours at room temperature.

Example 5

Verification of successful preparation of anti-interference photoelectrochemical disease marker sensors

In order to verify the successful preparation of the anti-interference photoelectrochemical disease marker sensor, the current signal response of the anti-interference photoelectrochemical disease marker sensor in the assembling process is monitored on a photoelectrochemical system, which comprises the following steps:

an LED lamp with the wavelength of 430nm is an excitation light source, and the light intensity is 350W/m²Recording of the photocurrent was done by the electrochemical workstation every 10s switching the light source on/off. And the three electrode bodies are: the modification area is 0.25cm²The sensing electrode is used as a working electrode, the Ag/AgCl electrode is used as a reference electrode, and the platinum wire electrode is used as a counter electrode; and the system applied voltage is 0.0V.

The photocurrent response of the anti-interference photoelectrochemical disease marker sensor during the assembly process is shown in fig. 7, from which it can be seen that CuInS₂The photocathode substrate has a relatively obvious photocurrent response (curve a); ZnIn₂S₄After nanocrystal deposition, CuInS₂/ZnIn₂S₄The photocurrent response of the photocathode was significantly increased (curve b) due to ZnIn₂S₄The sensitization of the nanocrystal; after the chitosan, the anchored capture antibody Ab and PEG-2000 were modified in sequence, the cathode photocurrent response gradually decreased (curves c to e), which are respectively due to the weak charge conductivity of chitosan, the apparent steric hindrance of the capture antibody Ab and the weak charge conductivity of PEG-2000. Therefore, the successful preparation of the anti-interference photoelectrochemical disease marker sensor is proved.

Example 6

Detection of target disease marker PSA by anti-interference photoelectrochemical disease marker sensor

Prostate Specific Antigen (PSA) is secreted by prostate epithelial cells, and is present in prostate tissue and semen in minute amounts in normal human serum. PSA is the first-choice marker for diagnosing prostate cancer at present, and is also significant for diagnosing prostate cancer without symptoms at early stage. Therefore, the PSA is taken as a target disease marker, has certain representativeness, and the specific detection process is as follows:

incubating 20 mu L of target detection object PSA with different concentrations at room temperature for 1h by using the anti-interference photoelectrochemical disease marker sensor prepared in the embodiment 4, and allowing the PSA and the capture antibody Ab to generate specific immunoreaction; after washing the electrodes with phosphate buffer (pH 7.4, 10mM), the photoelectrochemical test was performed.

The anti-interference photoelectrochemical disease marker sensor which completes PSA incubation carries out photocurrent signal test in phosphate buffer solution (pH 7.4, 0.1M) containing dissolved oxygen, and photocurrent signal detection is realized by using the inhibition effect of obvious PSA steric hindrance effect on sensor charge transfer.

The detection result is shown in fig. 8, and the result shows that the cathode photocurrent signal gradually decreases with the increase of the PSA concentration of the target, and is in the range of PSA concentration from 10pg/mL to 100ng/mL, and it can be seen from the graph that the cathode photocurrent signal is linearly related to the logarithm of the PSA concentration of the target, the linear correlation coefficient is 0.9991, and the lowest detection limit of the experiment is 10 pg/mL. The anti-interference photoelectrochemical disease marker sensor prepared by the method disclosed by the invention has higher sensitivity to a target detection substance.

Example 7

Anti-interference experiment of anti-interference photoelectrochemical disease marker sensor on biomacromolecule

The anti-interference photoelectrochemical disease marker sensor prepared in example 4 was incubated with 2.0mg/mL fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA) for 2h at room temperature, and after the electrodes were washed with phosphate buffer (pH 7.4, 10mM), a fluorescence imaging characterization test was performed. For comparison, an Ab-modified electrode not anchored with PEG-2000 was also incubated with FITC-BSA and the electrode washed under the same conditions.

Fluorescence imaging as shown in FIG. 9, it can be seen that a large number of fluorescent proteins FITC-BSA were observed to adhere to the Ab-modified electrode that was not anchored with PEG-2000 (FIG. 9A); after the prepared anti-interference photoelectrochemical disease marker sensor is incubated with fluorescent protein FITC-BSA for 2h, the surface is relatively clean, and no obvious nonspecific adsorption condition is seen (figure 9B). Therefore, the photoelectrochemical disease marker sensor is proved to have good large molecule nonspecific adsorption resistance.

Example 8

Evaluation of accuracy of anti-interference photoelectrochemical disease marker sensor in detection of PSA in serum

In order to evaluate the accuracy of the anti-interference photoelectrochemical disease marker sensor in detecting the target disease marker PSA, a standard recovery experiment in a serum sample is adopted for evaluation, and the method specifically comprises the following steps:

1) after the serum is diluted by 20 times, the serum is divided into three groups, and PSA with the concentration of 1ng/mL and 10ng/mL and 50ng/mL are respectively added;

2) the anti-interference photoelectrochemical disease marker sensor prepared in example 4 was incubated at room temperature for 20. mu.L of serum with different concentrations in a standard sample for 1h to allow PSA and capture antibody Ab to undergo specific immunoreaction, the electrodes were cleaned, and then dissolved oxygen (O) was added₂) The photocurrent signal test was performed in a phosphate buffer (pH 7.4, 0.1M) and compared with the photoelectrochemical detection performance of example 6.

The comparison result of the standard adding recovery experiment is shown in figure 10 (in the figure, PBS and Serum respectively represent buffer solution and Serum), the result shows that the recovery rate of the standard adding sample is within the range of 96.5-104.2%, and the relative standard deviation of the test result is within 5%, so that the application potential of the anti-interference photoelectrochemical disease marker sensor for accurately detecting PSA in the Serum sample is proved.

The previous description of the disclosed embodiments and examples is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An anti-interference photoelectrochemical disease marker sensor is characterized in that the disease marker sensor is prepared by successively modifying a capture antibody Ab and polyethylene glycol PEG corresponding to a disease marker on a photocathode, and detecting the target disease marker by utilizing the change of a photocurrent signal caused by the blocking effect of the obvious steric hindrance effect of the target disease marker Ag on the charge transfer of the sensor.

2. The anti-tamper photoelectrochemical disease marker sensor of claim 1, wherein said photocathode is CuInS₂/ZnIn₂S₄Photocathode of said CuInS₂/ZnIn₂S₄The photocathode is a P-type semiconductor material CuInS₂As a photocathode substrate, modifying a sensitizer ZnIn on the surface of the substrate₂S₄And obtaining the compound.

3. The anti-interference photoelectrochemical disease marker sensor of claim 1, wherein said capture antibody Ab is a PSA capture antibody Ab.

4. The method for preparing the anti-interference photoelectrochemical disease marker sensor according to claim 1, comprising the following steps:

(2) sequentially anchoring a capture antibody Ab and polyethylene glycol PEG to the CuInS prepared in the step (1)₂/ZnIn₂S₄And (4) a photocathode, namely the anti-interference photoelectrochemical disease marker sensor is prepared.

5. The method for preparing the anti-interference photoelectric chemical disease marker sensor according to claim 4, wherein in the step (1), CuCl is adopted as a hydrothermal method₂、InCl₃And CH₃CSNH₂Respectively as a Cu source, an In source and an S source, and directly growing CuInS on the FTO conductive glass₂Nano film to obtain CuInS₂A photocathode substrate; mixing the CuInS₂The photocathode substrate is sequentially immersed in Zn (NO)₃)₂、Na₂S、InCl₃And Na₂In the S solution, the CuInS is obtained by deposition and calcination through continuous ion layer adsorption and reaction method₂/ZnIn₂S₄A photocathode.

6. The method for preparing an anti-interference photoelectric chemical disease marker sensor according to claim 5, wherein the CuInS is prepared₂The molar ratio of the Cu source, the In source and the S source of the photocathode substrate is 2: 5: 15, the concentration of the Cu source is 4-20 mM, and the reaction temperature is 180 ℃; deposition of ZnIn₂S₄The number of adsorption and reaction cycles of the ion layer is 3-5.

7. The method for preparing the anti-interference photoelectric chemical disease marker sensor according to claim 4,in the step (2), in CuInS₂/ZnIn₂S₄Dripping chitosan and glutaraldehyde solution on the photocathode successively; then, dripping a capture antibody Ab, and incubating at low temperature; and then, dropwise adding amino-modified PEG to construct an anti-pollution interface, and incubating at room temperature to finally obtain the anti-interference photoelectrochemical disease marker sensor.

8. The method for preparing the anti-interference photoelectric chemical disease marker sensor according to claim 7, wherein the concentration of the capture antibody Ab incubated at low temperature is 50-250 μ g/mL, the molecular weight of the PEG is not less than 2000, and the concentration of the PEG incubated at room temperature is 1-4 mg/mL.

9. Use of the anti-interference photoelectrochemical disease marker sensor according to any one of claims 1 to 3 or the anti-interference photoelectrochemical disease marker sensor prepared by the method according to any one of claims 4 to 8 in an in vitro test product.