CN107064509A - Detect the preparation and application of the optical electro-chemistry immunosensor of carcinomebryonic antigen - Google Patents

Abstract

The invention discloses a kind of preparation and application study of the optical electro-chemistry immunosensor for detecting carcinomebryonic antigen.The zinc oxide nano rod nanometer sheet of growing three-dimensional hierarchy on the tin dioxide transparent conductive glass of doping fluorine, the cadmiumsulfide quantum dot and the aptamers of identification carcinomebryonic antigen that load substantial amounts of additive Mn using it and there is/the DNA probe of tellurium/cadmium selenide core shell quantum dot with the mark of aptamers hybridization, the polynary sensitization structure based on zinc oxide is formed, initial signal amplification is realized；The hybridization of DNA probe solution is set to depart from the sensibilization for the decrease that electrode surface is produced and the space steric effect of carcinomebryonic antigen and the conjugate itself of aptamers formation with reference to carcinomebryonic antigen specific recognition aptamers, further signal amplification is realized, and then realizes the Sensitive Detection to carcinomebryonic antigen.

Description

Detect the preparation and application of the optical electro-chemistry immunosensor of carcinomebryonic antigen

Technical field

The present invention relates to nano material technology, optical electro-chemistry signal detection technique and immunoassay detection technique field, more The specifically preparation and application of a kind of optical electro-chemistry immunosensor for Sensitive Detection carcinomebryonic antigen.

Background technology

As a kind of very important tumor markers, carcinomebryonic antigen is played the part of emphatically in the clinical diagnosis and treatment of cancer The role wanted.In recent years, various analysis methods are developed for the detection of carcinomebryonic antigen, as fluorescence, electrochemistry, electrification Learn the analysis methods such as luminous, colorimetric.Although these methods can realize the detection of carcinomebryonic antigen, there is complex operation, spirit in them The shortcomings of sensitivity is low, time-consuming, cost is high.Photoelectrochemical assay method is as a kind of emerging analysis method, due to its sensitivity High, simple to operate, low cost and other advantages cause extensive concern！Photoelectric activity material is the weight in photoelectrochemical assay method Part is wanted, conventional sensitization structure is typically half that different narrow band gaps are sensitized based on the semi-conducting material of broad-band gap Conductor material.The recombination rate in reduction sensitization structure electrical-hole pair, it is to improve photoelectricity to strengthen its absorption region to visible ray The key of chemical analysis performance.

The recognition element commonly used in traditional immunosensor is antibody, and it is typically to be produced by cell line or animal, Acquisition process is complex and high cost, in addition its less stable, is easily influenceed by high temperature, acid-base condition, these intrinsic defects It is significantly limit to be widely applied.Therefore it is badly in need of seeking new effective molecular recognition element.In addition, carcinomebryonic antigen is in people The content of class serum is relatively low, develops effective signal amplification mode, the sensitivity of its analysis detection is improved, for clinical cancer Analyzing and diagnosing has great importance.

The content of the invention

The purpose of the present invention is the oxidation of the growing three-dimensional hierarchy on the tin dioxide transparent conductive glass of doping fluorine Zinc nanometer rods-nanometer sheet, in the cadmiumsulfide quantum dot of the substantial amounts of additive Mn of its area load, wherein the tin ash of doping fluorine is saturating Bright electro-conductive glass is abbreviated as FTO, and zinc oxide nano rod-nanometer sheet of hierarchy writes a Chinese character in simplified form ZnO NRs-NSs, the vulcanization of additive Mn Cadmium quantum dot is abbreviated as CdS:Mn, by the use of aptamers as the recognition element of carcinomebryonic antigen, 5 ' ends are marked with cadmium telluride/cadmium selenide The DNA probe of core-shell quanta dots is captured to electrode surface, wherein telluride by the aptamers hybridization with modifying in electrode surface Cadmium/tellurium/cadmium selenide core shell quantum dot is abbreviated as CdTe@CdSe, forms ZnO NRs-NSs/CdS:The dual sensitization knots of Mn/CdTe@CdSe Structure, realizes initial photo-signal amplification；Carcinomebryonic antigen makes 5 ' ends be marked with CdTe@by specific recognition aptamers CdSe DNA probe solution hybridizes and departs from electrode surface, causes CdTe@CdSe sensibilizations to disappear, and reduces photo-signal, Other carcinomebryonic antigen and the biological composite of aptamers formation have big space steric effect, further reduction photoelectric current letter Number, the Sensitive Detection to carcinomebryonic antigen is realized based on above-mentioned signal amplification mode.

In order to solve the above-mentioned technical problem, the present invention is realized by following measures：

（1）Prepare ZnO NRs-NSs/FTO electrodes；

（2）Synthesize CdS:Mn：0.5-0.8 mmol cadmium nitrates and 0.04-0.07 mmol manganese acetates are dissolved in 50 mL secondary waters In, it is heated under magnetic stirring after 70 DEG C, the sodium sulfide solution that the concentration that 10 mL of addition are newly prepared is 0.03-0.06 M, Continuation is heated to reflux 2-5 h at 70 DEG C, then that its is molten by the precipitation of acquisition respectively with respectively washing 3 times of ethanol and secondary water In secondary water, the supernatant liquor for collecting yellow obtains CdS:Mn；

（3）Prepare CdTe@CdSe；

（4）Mark CdTe@CdSe on DNA probe, take 1 mL by step（3）The CdTe@CdSe and concentration of middle acquisition are 10 mM 1- (3- dimethylamino-propyls) -3- ethyl-carbodiimide hydrochlorides and concentration for 20 mM n-hydroxysuccinimide constitute Mixed liquor be added in the phosphate buffer solution for the pH 7.4 that 1 mL contains DNA probe, DNA probe concentration used is 10 Nmol, its 5 ' end carries amino, at 37 DEG C after the h of oscillating reactions 2, stands 12 h, unreacted DNA is removed using microporous pipe Probe, the phosphate-buffered that the DNA probe that the mark of acquisition has CdSe is finally dispersed in into 1 mL pH 7.4 again is molten In liquid, wherein phosphate buffer solution is abbreviated as PBS, and 1- (3- dimethylamino-propyls) -3- ethyl-carbodiimide hydrochlorides are write a Chinese character in simplified form For EDC, n-hydroxysuccinimide is abbreviated as NHS, and the DNA probe for being marked with CdTe@CdSe is abbreviated as CdTe@CdSe-DNA；

（5）The structure of optical electro-chemistry immunosensor：By step（1）The ZnO NRs-NSs/FTO electrodes of middle acquisition are immersed in dense Spend in the solution for 2% 3- aminopropyl triethoxysilanes, hatch 1 h, after being washed with the PBS of pH 7.4, in its surface drop coating 20 μ L are by step（2）The CdS of middle acquisition:The mixing for the NHS compositions that the EDC and concentration that Mn and concentration are 10 mM are 20 mM Liquid, hatches after 2 h at room temperature, and the unreacted reagent of removing is washed with the PBS of pH 7.4, by 10 μ L concentration for 5.0 μM with The aptamers drop coating of carcinomebryonic antigen specific recognition is to electrode surface, and aptamers 3 ' used, which are held, carries amino, and at 4 DEG C Hatch 12 h, washed and removed after unnecessary aptamers with the PBS of pH 7.4, continue the own sulphur of mM 6- hydroxyls -1- of 20 μ L of drop coating 1 Alcohol is used to block nonspecific binding site, hatches at room temperature after 1 h, is washed with the PBS of pH 7.4, then by 20 μ L steps （4）The CdTe@CdSe-DNA drop coatings of middle acquisition hatch 2 h to electrode surface and at 37 DEG C, and removing is washed with the PBS of pH 7.4 After unnecessary CdTe@CdSe-DNA, the carcinomebryonic antigen of the μ L various concentrations of drop coating 10 is hatched at 37 DEG C and pH 7.4 is used after 2 h PBS is washed, and completes the structure of optical electro-chemistry immunosensor；

（6）Photo-signal is detected：By step（5）The ZnO NRs-NSs/FTO electrodes of middle acquisition, platinum are to electrode and Ag/ Photo-signal detection is carried out in the three-electrode system of AgCl reference electrodes composition, detection method used is bent for current-vs-time Collimation method, voltage is 0.0 V, and excitation wavelength range is 200-2500 nm, and an excitation source switch is switched every 10 s, used Detection solution contain the PBS solutions of pH 7.4 of 0.01 M hydrogen peroxide for 5 mL, and to lead to nitrogen using preceding detection solution The min of gas deoxygenation 15, with the increase of carcinomebryonic antigen concentration, photo-signal is gradually decreased, and passes through carcinomebryonic antigen concentration and photoelectricity Relation between stream signal can realize the quantitative detection to carcinomebryonic antigen.

It is of the present invention to prepare concretely comprising the following steps for ZnO NRs-NSs/FTO electrodes：

（1）Electrodeposition process prepares ZnO NRs/FTO electrodes：FTO is cleaned by ultrasonic 10 min with ethanol, acetone, secondary water successively Afterwards, in the zinc acetate seed solution that spin coating concentration in FTO surfaces is 40 mM, rotating speed is 1000 r/min, and the time is 30 s, then By the FTO after spin coating in 120 DEG C of dry 10 min, repeat after above-mentioned " spin coating-drying " process 6 times, by FTO electrodes, The three-electrode system that Ag/AgCl reference electrodes and platinum are constituted to electrode carries out electro-deposition operation, and sedimentation potential is 0.0V, deposition electricity It by zinc nitrate that concentration is 30-60 mM, concentration is that 40-60 mM ammonium acetate and concentration are 50-80 mM ethylenediamine to solve liquid to be The mixed liquor of composition, depositing temperature is 60-80 DEG C, and sedimentation time is 12 h, is washed with secondary water and absolute ethyl alcohol after the completion of deposition Wash and in 60 DEG C of dry 30 min；

（2）Hydro-thermal method prepares ZnO NRs-NSs/FTO electrodes：The insertion of above-mentioned acquisition ZnO NRs/FTO electrodes is mixed containing 10 mL In the 25 mL autoclaves for closing liquid, and conduction is set to place downwards, described mixed liquor is by zinc nitrate, dense of the concentration for 8-12 mM The sodium citrate composition that the hexamethylenetetramine and concentration that degree is 8-12 mM are 0.5-2 mM, 6-9 h are heated at 60-70 DEG C, It is to be cooled to after room temperature, calcine 30 min with secondary water washing and at 350 DEG C, finally obtain ZnO NRs-NSs/FTO electrodes.

It is of the present invention to prepare concretely comprising the following steps for CdTe@CdSe：

（1）Prepare CdTe nanometer crystalline body：0.3-0.6 mmol cadmium nitrates and 0.1-0.3 the g sodium citrate being dehydrated are dissolved in 50 In mL secondary waters, 50-55 μ L 3- mercaptopropionic acids are then added, with the sodium hydrate regulator solution pH to 10.5 that concentration is 1 M Afterwards, 0.1-0.2 mmol sodium tellurites and 45-60 mg sodium borohydrides are added, 1-3 h are heated to reflux at 100 DEG C, finally will Reacted mixed liquor is multiple with normal propyl alcohol centrifuge washing, and being deposited at 60 DEG C for obtaining is dried into 30 min acquisitions CdTe Nanocrystal；

（2）Prepare CdTe@CdSe：Sodium hydrogen selenide solution is prepared first, by 0.2-0.3 mmol selenium powders and 0.8-1.2 mmol boron Sodium hydride is dissolved in the secondary water of 10 mL deoxygenations, under magnetic stirring, 60 DEG C of min of oil bath heating 50, and whole process is in nitrogen Carried out under gas shielded；Then the solution containing divalent cadmium ion is prepared, by 0.2-0.5 mmol cadmium nitrates and 30-35 μ L 3- mercaptos Base propionic acid is dissolved in the secondary water of 10 mL deoxygenations, then with the sodium hydrate regulator solution pH to 10.5 that concentration is 1 M；Finally Prepare after CdTe@CdSe, the secondary water that above-mentioned acquisition CdTe nanometer crystalline body is dissolved in 25 mL deoxygenations, with the hydrogen-oxygen that concentration is 1 M Change sodium and adjust pH value of solution to 10.5, under the protection of nitrogen, first 1-5 mL, which are slowly added dropwise, contains the molten of divalent cadmium ion Liquid, then 1-5 mL sodium hydrogen selenide solution is slowly added dropwise, in 70-90 DEG C of heating response 20-60 min, by the anti-of acquisition Answer mixed liquor normal propyl alcohol centrifuge washing repeatedly, be finally deposited in what is obtained to dry at 60 DEG C and 30 min and be dispersed in again It is standby in the secondary water of 25 mL deoxygenations.

Beneficial effects of the present invention：

（1）ZnO NRs-NSs/FTO electrodes prepared by the present invention, with good electric conductivity, biocompatibility and big ratio table Area, can greatly increase the load capacity of quantum dot and signaling molecule, further amplify signal Analysis, so as to improve detection Sensitivity.

（2）Utilize CdS:Mn and CdTe@CdSe are sensitized ZnO jointly, and the polynary sensitization structure of formation not only can be effectively Suppress the compound of electron-hole pair and the absorption to visible ray can be strengthened, greatly strengthen photo-signal, further carry The sensitivity of high analyte.

（3）The present invention replaces traditional antibody as the recognition element of carcinomebryonic antigen using aptamers, can greatly drop The complexity and cost of harmonic analysis operation, in addition, using the hybridization of carcinomebryonic antigen specific recognition aptamers inducing DNA probe solution Depart from electrode surface, cause CdTe@CdSe sensibilizations disappearances and carcinomebryonic antigen and the biological composite itself of aptamers formation Space steric effect realize that signal amplifies, signal amplification mode is sensitive, efficient, treatment for clinical cancer and diagnosis tool There is important meaning.

Embodiment:

For a better understanding of the present invention, with reference to the embodiment content that the present invention is furture elucidated, but present disclosure It is not limited solely to the following examples.

Embodiment 1:Optical electro-chemistry immunosensor is used for the detection of carcinomebryonic antigen

（1）ZnO NRs-NSs/FTO electrodes are prepared, ZnO NRs/FTO electrodes are prepared first with electrodeposition process：By FTO successively It is cleaned by ultrasonic with ethanol, acetone, secondary water after 10 min, in the zinc acetate seed solution that spin coating concentration in FTO surfaces is 40 mM, Rotating speed is 1000 r/min, and the time is 30 s, then repeats the FTO after spin coating above-mentioned in 120 DEG C of dry 10 min After " spin coating-drying " process 6 times, the three-electrode system that electrode is constituted is entered by FTO electrodes, Ag/AgCl reference electrodes and platinum Row electro-deposition is operated, and sedimentation potential is 0.0V, and deposited electrolyte is by zinc nitrate that concentration is 50 mM, the vinegar that concentration is 50 mM Sour ammonium and concentration are 70 mixed liquor that constitutes of ethylenediamine, and depositing temperature is 70 DEG C, after the completion of sedimentation time is 12 h, deposition Washed with secondary water and absolute ethyl alcohol and in 60 DEG C of dry 30 min；Then ZnO NRs-NSs/FTO electricity is prepared using hydro-thermal method Pole：By in above-mentioned 25 mL autoclaves of the middle acquisition ZnO NRs/FTO electrodes insertion containing 10 mL mixed liquors, and make it is conductive towards Lower to place, the hexamethylenetetramine and concentration that described mixed liquor is 10 mM by zinc nitrate that concentration is 10 mM, concentration are 1 MM sodium citrate composition, 6 h are heated at 70 DEG C, to be cooled to after room temperature, and 30 are calcined with secondary water washing and at 350 DEG C Min, finally obtains ZnO NRs-NSs/FTO electrodes；

（2）Synthesize CdS:Mn：0.6 mmol cadmium nitrates and 0.06 mmol manganese acetates are dissolved in 50 mL secondary waters, in magnetic force It is heated under stirring after 70 DEG C, the sodium sulfide solution that the concentration that 10 mL of addition are newly prepared is 0.05 M, continues to add at 70 DEG C Heat 3 h of backflow, by the precipitation of acquisition respectively with respectively washing 3 times of ethanol and secondary water, are then dissolved in secondary water, collect yellow The supernatant liquor of color obtains CdS:Mn；

（3）CdTe@CdSe are prepared, CdTe nanometer crystalline body is prepared first：The citric acid that 0.5 mmol cadmium nitrates and 0.2 g are dehydrated Sodium is dissolved in 50 mL secondary waters, then adds 52 μ L 3- mercaptopropionic acids, with the sodium hydrate regulator solution pH that concentration is 1 M To after 10.5,0.1 mmol sodium tellurites and 50 mg sodium borohydrides are added, 2 h are heated to reflux at 100 DEG C, finally will reaction Mixed liquor afterwards is multiple with normal propyl alcohol centrifuge washing, and being deposited at 60 DEG C for obtaining is dried into CdTe nanometers of 30 min acquisitions Crystal；Then CdTe@CdSe are prepared：Sodium hydrogen selenide solution is prepared first, by 0.25 mmol selenium powders and 1.0 mmol sodium borohydrides In the secondary water for being dissolved in 10 mL deoxygenations, under magnetic stirring, 60 DEG C of min of oil bath heating 50, whole process is protected in nitrogen It is lower to carry out；Then the solution containing divalent cadmium ion is prepared, 0.3 mmol cadmium nitrates and 32 μ L 3- mercaptopropionic acids are dissolved in 10 In the secondary water of mL deoxygenations, then with the sodium hydrate regulator solution pH to 10.5 that concentration is 1 M；Finally prepare CdTe@CdSe： After the secondary water that above-mentioned acquisition CdTe nanometer crystalline body is dissolved in 25 mL deoxygenations, with the sodium hydrate regulator solution pH that concentration is 1 M To 10.5, under the protection of nitrogen, the solution that 3 mL contain divalent cadmium ion is first slowly added dropwise, then slowly add dropwise Enter 3 mL sodium hydrogen selenide solution, in 80 DEG C of min of heating response 30, reaction mixture is more with normal propyl alcohol centrifuge washing by obtaining It is secondary, finally it is deposited in what is obtained to dry at 60 DEG C and 30 min and is dispersed in again in the secondary water of 25 mL deoxygenations, it is standby；

（4）Mark CdTe@CdSe on DNA probe, take 1 mL by step（3）The CdTe@CdSe and concentration of middle acquisition are 10 mM EDC and concentration for 20 mM NHS constitute mixed liquor be added in the PBS of pH 7.4 that 1 mL contains DNA probe, it is used DNA probe concentration is 10 nmol, and its 5 ' end carries amino, at 37 DEG C after the h of oscillating reactions 2, stands 12 h, utilizes microporous pipe Unreacted DNA probe is removed, finally the CdTe@CdSe-DNA of acquisition are dispersed in the PBS of 1 mL pH 7.4 again；

（5）The structure of optical electro-chemistry immunosensor：By step（1）The ZnO NRs-NSs/FTO electrodes of middle acquisition are immersed in dense Spend in the solution for 2% 3- aminopropyl triethoxysilanes, hatch 1 h, after being washed with the PBS of pH 7.4, in its surface drop coating 20 μ L are by step（2）The CdS of middle acquisition:The mixing for the NHS compositions that the EDC and concentration that Mn and concentration are 10 mM are 20 mM Liquid, hatches after 2 h at room temperature, and the unreacted reagent of removing is washed with the PBS of pH 7.4, by 10 μ L concentration for 5.0 μM with The aptamers drop coating of carcinomebryonic antigen specific recognition is to electrode surface, and aptamers 3 ' used, which are held, carries amino, and at 4 DEG C Hatch 12 h, washed and removed after unnecessary aptamers with the PBS of pH 7.4, continue the own sulphur of mM 6- hydroxyls -1- of 20 μ L of drop coating 1 Alcohol is used to block nonspecific binding site, hatches at room temperature after 1 h, is washed with the PBS of pH 7.4, then by 20 μ L steps （4）The CdTe@CdSe-DNA drop coatings of middle acquisition hatch 2 h to electrode surface and at 37 DEG C, and removing is washed with the PBS of pH 7.4 After unnecessary CdTe@CdSe-DNA, the carcinomebryonic antigen of the μ L various concentrations of drop coating 10 is hatched at 37 DEG C and pH 7.4 is used after 2 h PBS is washed, and completes the structure of optical electro-chemistry immunosensor；

（6）Photo-signal is detected：By step（5）The ZnO NRs-NSs/FTO electrodes of middle acquisition, platinum are to electrode and Ag/ Photo-signal detection is carried out in the three-electrode system of AgCl reference electrodes composition, detection method used is bent for current-vs-time Collimation method, voltage is 0.0 V, and excitation wavelength range is 200-2500 nm, and an excitation source switch is switched every 10 s, used Detection solution contain the PBS solutions of pH 7.4 of 0.01 M hydrogen peroxide for 5 mL, and to lead to nitrogen using preceding detection solution The min of gas deoxygenation 15, with the increase of carcinomebryonic antigen concentration, photo-signal is gradually decreased, and passes through carcinomebryonic antigen concentration and photoelectricity Relation between stream signal can realize the quantitative detection to carcinomebryonic antigen.

SEQUENCE LISTING

<110>University Of Ji'nan

<120>Detect the preparation and application of the optical electro-chemistry immunosensor of carcinomebryonic antigen

<130> 2017

<160> 2

<170> PatentIn version 3.3

<210> 1

<211> 18

<212> DNA

<213>It is artificial synthesized

<400> 1

ataccagctt attcaatt 18

<210> 2

<211> 12

<212> DNA

<213>It is artificial synthesized

<400> 2

aattgaataa gc 12

Claims (3)

1. a kind of preparation method for the optical electro-chemistry immunosensor for detecting carcinomebryonic antigen, it is characterized in that comprising the following steps：

（1）Zinc oxide nano rod-nanometer sheet of hierarchy is grown in the tin dioxide transparent conductive glass surface of doping fluorine, its The tin dioxide transparent conductive glass of middle doping fluorine is abbreviated as FTO, and zinc oxide nano rod-nanometer sheet of hierarchy writes a Chinese character in simplified form ZnO NRs-NSs, obtains ZnO NRs-NSs/FTO electrodes；

（2）Synthesize the cadmiumsulfide quantum dot of additive Mn：0.5-0.8 mmol cadmium nitrates and 0.04-0.07 mmol manganese acetates is molten In 50 mL secondary waters, it is heated under magnetic stirring after 70 DEG C, the concentration that 10 mL of addition are newly prepared is 0.03-0.06 M Sodium sulfide solution, continuation is heated to reflux 2-5 h at 70 DEG C, by the precipitation of acquisition respectively with the respectively washing 3 of ethanol and secondary water It is secondary, it is then dissolved in secondary water, the supernatant liquor for collecting yellow obtains the cadmiumsulfide quantum dot of additive Mn, wherein additive Mn Cadmiumsulfide quantum dot be abbreviated as CdS:Mn；

（3）Cadmium telluride/tellurium/cadmium selenide core shell quantum dot is prepared, it is abbreviated as CdTe@CdSe；

（4）Mark CdTe@CdSe on DNA probe, take 1 mL by step（3）The CdTe@CdSe and concentration of middle acquisition are 10 mM 1- (3- dimethylamino-propyls) -3- ethyl-carbodiimide hydrochlorides and concentration for 20 mM n-hydroxysuccinimide constitute Mixed liquor be added in the phosphate buffer solution for the pH 7.4 that 1 mL contains DNA probe, DNA probe concentration used is 10 Nmol, its 5 ' end carries amino, at 37 DEG C after the h of oscillating reactions 2, stands 12 h, unreacted DNA is removed using microporous pipe Probe, the phosphate-buffered that the DNA probe that the mark of acquisition has CdSe is finally dispersed in into 1 mL pH 7.4 again is molten In liquid, wherein phosphate buffer solution is abbreviated as PBS, and 1- (3- dimethylamino-propyls) -3- ethyl-carbodiimide hydrochlorides are write a Chinese character in simplified form For EDC, n-hydroxysuccinimide is abbreviated as NHS, and the DNA probe for being marked with CdTe@CdSe is abbreviated as CdTe@CdSe-DNA；

（5）The structure of optical electro-chemistry immunosensor：By step（1）The ZnO NRs-NSs/FTO electrodes of middle acquisition are immersed in dense Spend in the solution for 2% 3- aminopropyl triethoxysilanes, hatch 1 h, after being washed with the PBS of pH 7.4, in its surface drop coating 20 μ L are by step（2）The CdS of middle acquisition:The mixing for the NHS compositions that the EDC and concentration that Mn and concentration are 10 mM are 20 mM Liquid, hatches after 2 h at room temperature, and the unreacted reagent of removing is washed with the PBS of pH 7.4, by 10 μ L concentration for 5.0 μM with The aptamers drop coating of carcinomebryonic antigen specific recognition is to electrode surface, and aptamers 3 ' used, which are held, carries amino, and at 4 DEG C Hatch 12 h, washed and removed after unnecessary aptamers with the PBS of pH 7.4, continue the own sulphur of mM 6- hydroxyls -1- of 20 μ L of drop coating 1 Alcohol is used to block nonspecific binding site, hatches at room temperature after 1 h, is washed with the PBS of pH 7.4, then by 20 μ L steps （4）The CdTe@CdSe-DNA drop coatings of middle acquisition hatch 2 h to electrode surface and at 37 DEG C, and removing is washed with the PBS of pH 7.4 After unnecessary CdTe@CdSe-DNA, the carcinomebryonic antigen of the μ L various concentrations of drop coating 10 is hatched at 37 DEG C and pH 7.4 is used after 2 h PBS is washed, and completes the structure of optical electro-chemistry immunosensor；

（6）Photo-signal is detected：By step（5）The ZnO NRs-NSs/FTO electrodes of middle acquisition, platinum are to electrode and Ag/ Photo-signal detection is carried out in the three-electrode system of AgCl reference electrodes composition, detection method used is bent for current-vs-time Collimation method, voltage is 0.0 V, and excitation wavelength range is 200-2500 nm, and an excitation source switch is switched every 10 s, used Detection solution contain the PBS solutions of pH 7.4 of 0.01 M hydrogen peroxide for 5 mL, and to lead to nitrogen using preceding detection solution The min of gas deoxygenation 15, with the increase of carcinomebryonic antigen concentration, photo-signal is gradually decreased, and passes through carcinomebryonic antigen concentration and photoelectricity Relation between stream signal can realize the quantitative detection to carcinomebryonic antigen.

2. a kind of preparation method for the optical electro-chemistry immunosensor for detecting carcinomebryonic antigen according to claims 1, it is special Levying is, described prepares concretely comprising the following steps for ZnO NRs-NSs/FTO electrodes：

（1）Electrodeposition process prepares ZnO NRs/FTO electrodes：FTO is cleaned by ultrasonic 10 min with ethanol, acetone, secondary water successively Afterwards, in the zinc acetate seed solution that spin coating concentration in FTO surfaces is 40 mM, rotating speed is 1000 r/min, and the time is 30 s, then By the FTO after spin coating in 120 DEG C of dry 10 min, repeat after above-mentioned " spin coating-drying " process 6 times, by FTO electrodes, The three-electrode system that Ag/AgCl reference electrodes and platinum are constituted to electrode carries out electro-deposition operation, and sedimentation potential is 0.0V, deposition electricity It by zinc nitrate that concentration is 30-60 mM, concentration is that 40-60 mM ammonium acetate and concentration are 50-80 mM ethylenediamine to solve liquid to be The mixed liquor of composition, depositing temperature is 60-80 DEG C, and sedimentation time is 12 h, is washed with secondary water and absolute ethyl alcohol after the completion of deposition Wash and in 60 DEG C of dry 30 min；

（2）Hydro-thermal method prepares ZnO NRs-NSs/FTO electrodes：The insertion of above-mentioned acquisition ZnO NRs/FTO electrodes is mixed containing 10 mL In the 25 mL autoclaves for closing liquid, and conduction is set to place downwards, described mixed liquor is by zinc nitrate, dense of the concentration for 8-12 mM The sodium citrate composition that the hexamethylenetetramine and concentration that degree is 8-12 mM are 0.5-2 mM, 6-9 h are heated at 60-70 DEG C, It is to be cooled to after room temperature, calcine 30 min with secondary water washing and at 350 DEG C, finally obtain ZnO NRs-NSs/FTO electrodes.

3. a kind of preparation method for the optical electro-chemistry immunosensor for detecting carcinomebryonic antigen according to claims 1, it is special Levying is, described prepares concretely comprising the following steps for CdTe@CdSe：

（1）Prepare CdTe nanometer crystalline body：0.3-0.6 mmol cadmium nitrates and 0.1-0.3 the g sodium citrate being dehydrated are dissolved in 50 In mL secondary waters, 50-55 μ L 3- mercaptopropionic acids are then added, with the sodium hydrate regulator solution pH to 10.5 that concentration is 1 M Afterwards, 0.1-0.2 mmol sodium tellurites and 45-60 mg sodium borohydrides are added, 1-3 h are heated to reflux at 100 DEG C, finally will Reacted mixed liquor is multiple with normal propyl alcohol centrifuge washing, and being deposited at 60 DEG C for obtaining is dried into 30 min acquisitions CdTe Nanocrystal；

（2）Prepare CdTe@CdSe：Sodium hydrogen selenide solution is prepared first, by 0.2-0.3 mmol selenium powders and 0.8-1.2 mmol boron Sodium hydride is dissolved in the secondary water of 10 mL deoxygenations, under magnetic stirring, 60 DEG C of min of oil bath heating 50, and whole process is in nitrogen Carried out under gas shielded；Then the solution containing divalent cadmium ion is prepared, by 0.2-0.5 mmol cadmium nitrates and 30-35 μ L 3- mercaptos Base propionic acid is dissolved in the secondary water of 10 mL deoxygenations, then with the sodium hydrate regulator solution pH to 10.5 that concentration is 1 M；Finally Prepare after CdTe@CdSe, the secondary water that above-mentioned acquisition CdTe nanometer crystalline body is dissolved in 25 mL deoxygenations, with the hydrogen-oxygen that concentration is 1 M Change sodium and adjust pH value of solution to 10.5, under the protection of nitrogen, first 1-5 mL, which are slowly added dropwise, contains the molten of divalent cadmium ion Liquid, then 1-5 mL sodium hydrogen selenide solution is slowly added dropwise, in 70-90 DEG C of heating response 20-60 min, by the anti-of acquisition Answer mixed liquor normal propyl alcohol centrifuge washing repeatedly, be finally deposited in what is obtained to dry at 60 DEG C and 30 min and be dispersed in again It is standby in the secondary water of 25 mL deoxygenations.