阅读说明：本技术 一种BVO/CN/Co光阳极传感器的制备方法 (Preparation method of BVO/CN/Co photo-anode sensor ) 是由 补钰煜 王琳 敖金平 于 2021-08-26 设计创作，主要内容包括：本发明提供了一种BVO/CN/Co光阳极传感器的制备方法；包括：步骤1,钒酸铋基底的制备：步骤2,在钒酸铋薄膜旋涂50ul氮化碳分散液3次,在250℃下热处理30分钟,得钒酸铋氮化碳光阳极；将Co催化剂配置成0.5mM的溶液,将得到的钒酸铋氮化碳光阳极浸泡2min,退火30min,得BVO/CN/Co光阳极传感器。本发明在BVO/CN/Co光阳极传感器的搭建中,氮化碳和Co助催化剂协同作用,在减少表面态,提高载流子浓度和增加反应活性位点方面都有促进作用,使得光阳极的光电性能得到大幅度的提高；本发明引入Π-rich材料与钒酸铋材料复合后,利用有机共轭材料吸附适配体,降低传感器的制造成本。(The invention provides a preparation method of a BVO/CN/Co photo-anode sensor; the method comprises the following steps: step 1, preparing a bismuth vanadate substrate: step 2, spin-coating 50ul of carbon nitride dispersion liquid on the bismuth vanadate film for 3 times, and carrying out heat treatment at 250 ℃ for 30 minutes to obtain a bismuth vanadate carbon nitride photo-anode; and (3) preparing a Co catalyst into a 0.5mM solution, soaking the obtained bismuth vanadate carbon nitride photo-anode for 2min, and annealing for 30min to obtain the BVO/CN/Co photo-anode sensor. In the construction of the BVO/CN/Co photo-anode sensor, the carbon nitride and the Co cocatalyst have a promoting effect on reducing the surface state, improving the carrier concentration and increasing the reactive active sites under the synergistic effect, so that the photoelectric performance of the photo-anode is greatly improved; after the II-rich material and the bismuth vanadate material are compounded, the aptamer is adsorbed by using the organic conjugated material, so that the manufacturing cost of the sensor is reduced.)

1. A preparation method of a BVO/CN/Co photo-anode sensor is characterized by comprising the following steps:

step 1, preparing a bismuth vanadate substrate:

dissolving 3mmol of bismuth vanadate pentahydrate and 40mmol of sodium iodide in 100ml of ultrapure water, adjusting the pH value of the solution to 1.2 by nitric acid, adding 0.0135mol of ethanol solution of p-benzoquinone, and uniformly stirring to obtain an electrodeposition solution;

a three-electrode system is adopted, a working electrode is cleaned FTO, a counter electrode is a platinum sheet, and a reference electrode is a silver-silver chloride reference electrode; depositing potential is-0.5V, and depositing time is 600 seconds to obtain the bismuth oxyiodide film;

coating 40ul of vanadyl acetylacetonate solution on the bismuth oxyiodide film, drying at 50 ℃, and annealing in a muffle furnace at 450 ℃ for 60 minutes to obtain a bright yellow film;

removing redundant vanadium pentoxide from the bright yellow film in 1M sodium hydroxide solution to obtain a bismuth vanadate film;

step 2, preparation of BVO/CN/Co photo-anode sensor

Ultrasonically dispersing 50mg of carbon nitride powder subjected to two times of thermal oxidation in 150ml of a mixture with a volume ratio of 1: 1, continuously treating for 4 hours with 100 percent of ultrasonic power to obtain milky carbon nitride dispersion liquid;

under the condition of rotating speed of 3000 r/s, 50ul of carbon nitride dispersion liquid is coated on the bismuth vanadate film in a spinning mode for 3 times, and heat treatment is carried out for 30 minutes at 250 ℃ to obtain a bismuth vanadate carbon nitride photo-anode;

and (3) preparing a Co catalyst into a 0.5mM solution, soaking the obtained bismuth vanadate carbon nitride photoanode for 2min, washing the obtained bismuth vanadate carbon nitride photoanode with deionized water, and annealing the obtained bismuth vanadate carbon nitride photoanode for 30min at 350 ℃ in an inert atmosphere to obtain the BVO/CN/Co photoanode sensor.

2. The method of making a BVO/CN/Co photo-anode sensor according to claim 1, wherein the Co catalyst is prepared by: 0.238g of CoCl₂·6H₂O and 0.148g NH₄F was dissolved in 10ml ethanol and 0.234g N- (phosphonomethyl) iminodiacetic acid (H) was added₄PMIDA), stirring with force;

then add 0.6mL [ Me ]₄N]Stirring the OH solution until a uniform reaction mixture is formed; the reaction mixture was crystallized in a 25mL teflon-lined autoclave at 170 ℃ for 5 days, collected by vacuum filtration, washed thoroughly with ethanol, and air-dried.

Technical Field

The invention belongs to the field of sensors; in particular to a preparation method of a BVO/CN/Co photo-anode sensor.

Background

At present, a simple, fast and sensitive method for analyzing biomolecules is one of the most important and popular research topics in analytical chemistry. Especially has great attraction in the fields of disease diagnosis, environmental monitoring, drug analysis, food safety analysis, life analysis, pathogenic microorganism research and the like. The Photoelectrochemical (PEC) analysis method is a new analysis method developed after optical, photochemical, electrochemical methods. The method has the obvious advantages of simplicity, high efficiency, low background signal, high sensitivity, good stability and the like, thereby being highly concerned and widely researched by broad scholars. In the development process of the PEC biosensor, screening of photoelectric materials with excellent performance, incorporation of efficient signal amplification strategies, introduction of molecular recognition elements with strong specificity, development of novel and practical analysis methods, and the like, play an important role in improving various analysis performances of the PEC biosensor and realizing high-sensitivity detection of biomolecules.

Bismuth vanadate (BiVO)₄) Has a proper band gap of 2.4eV, can ensure visible light collection to about 500nm, and the valence band potential of bismuth vanadate is suitable for stable photocatalytic oxidation in a neutral electrolyte solution, so that the bismuth vanadate is an extremely promising PEC photoelectrode material. However, BiVO is due to the high recombination rate of photogenerated electron-hole pairs₄The photocurrent density obtained by the photo-anode is far lower than the theoretical value (7.5 mA/cm) under the irradiation of 1 sunlight²) Therefore, much work can be focused on this study.

In the prior art, a novel photocurrent direction switch system (CdSe QDs// NPC-ZnO polyhedron) is used for a PEC biosensor, and the sensitivity detection is carried out on miRNA-155 (the linear range is 0.1fM-10 nM; the detection limit is 49 aM). In addition, the biosensor has good stability, repeatability and selectivity due to the different directions of the initial photocurrent and the detected photocurrent. The photoelectric direction switch system combined with the strand displacement amplification reaction strategy provides a new idea for photoelectric sensor analysis, and false positive or false negative signals are avoided as far as possible.

In addition, there is a PEC-EC dual-mode biosensor based on multifunctional DNA spheres as signal indicators. The ternary Y structure cleavage cycle associated with the target spot reacts a large amount of output DNA, and can trigger RCA to form a PDA + decoding multifunctional DNA sphere in situ on a TiO2 substrate. Due to the proximity of the DNA spheres to the TiO2 substrate, an efficient PDA + -TiO2 sensitized structure and fast electron transfer can be achieved, resulting in extremely high PEC and EC signals. The method not only avoids complex combination of different signal indexes, but also remarkably improves the sensitivity (PEC linear range is 0.1fM-1 nM; detection limit is 37 aM; EC linear range is 2fM-500 pM; detection limit is 670aM) by utilizing the cleavage cycle amplification and RCA strategy, and provides a new development prospect for accurate, sensitive and convenient future biological analysis.

Mixing pyramid-shaped Cu₂O grows on the fiber network with gold nano particles in situ and then uses BiVO₄-Bi₂S₃And (4) carrying out sensitization on the heterostructure to form a cascade sensitization structure. Then, through the coupling of target recovery reaction induced by Dual Specificity Nuclease (DSN) and multi-branched hybridization chain reaction (MHCR), DNA dendritic molecules are introduced into a photoelectric cathode sensing interface to effectively catalyze H₂O₂The method has the advantages of high selectivity, high stability and good reproducibility, and the cathode PEC sensing platform based on paper has wide application prospect in clinical miRNAs diagnosis.

In summary, the current semiconductor photoelectric biosensor research focuses mainly on the biological recognition unit, such as combining the nucleic acid amplification technology with the photoelectric technology to increase the signal of the detection object, but this results in more complicated operation. And many researches adopt noble metal to bind proper ligands, so that the cost of the sensor is increased, and the actual application is not facilitated. Aiming at the problems, the invention aims at the photoelectric material of the photoelectrode, regulates and controls the electron mobility and the charge separation efficiency of the photoelectric semiconductor, and prepares the ultra-sensitive low-cost semiconductor photoelectric nucleic acid tumor marker detection sensor.

Disclosure of Invention

The invention aims to provide a preparation method of a BVO/CN/Co photo-anode sensor.

The invention is realized by the following technical scheme:

the invention relates to a preparation method of a BVO/CN/Co photo-anode sensor, which comprises the following steps:

step 1, preparing a bismuth vanadate substrate:

preparing a uniform and stable bismuth vanadate film (BVO) by adopting a typical method for converting bismuth vanadate by electro-deposition of bismuth oxyiodide; dissolving 3mmol of bismuth vanadate pentahydrate and 40mmol of sodium iodide in 100ml of ultrapure water, adjusting the pH of the solution to 1.2 by using nitric acid, adding 0.0135mol of ethanol solution of p-benzoquinone, and uniformly stirring to obtain an electrodeposition solution;

a three-electrode system is adopted, a working electrode is cleaned FTO, a counter electrode is a platinum sheet, and a reference electrode is a silver-silver chloride reference electrode. Depositing potential is-0.5V, and depositing time is 600 seconds to obtain the bismuth oxyiodide film;

coating 40ul of vanadyl acetylacetonate solution on the deposited bismuth oxyiodide film, drying at 50 ℃, and annealing at 450 ℃ for 60 minutes in a muffle furnace to obtain a bright yellow film; removing redundant vanadium pentoxide from the obtained film in 1M sodium hydroxide solution to obtain a bismuth vanadate film;

step 2, preparing a BVO/CN/Co photo-anode sensor:

ultrasonically dispersing 50mg of carbon nitride powder subjected to two times of thermal oxidation in a 1: 1 ethanol: in water (total 150ml), continuously processing for 4 hours with 100 percent of ultrasonic power to obtain milky carbon nitride dispersion liquid; spin coat 50ul 3 times on BVO film at 3000 rpm. Heat treating at 250 deg.c for 30min to obtain bismuth vanadate carbon nitride photo anode (BVO/CN);

and (3) preparing a Co catalyst into a 0.5mM solution, soaking the obtained BVO/CN electrode for 2min, washing the electrode with deionized water, and annealing the electrode at 350 ℃ for 30min in an inert atmosphere to obtain the BVO/CN/Co photo-anode sensor.

The preparation method of the molecular cobalt catalyst comprises the following steps: 0.238g of CoCl₂·6H₂O and 0.148g NH₄F was dissolved in 10ml ethanol and 0.234g N- (phosphonomethyl) iminodiacetic acid (H) was added₄PMIDA), stirring with force; then, 0.6mL of [ Me ] was added₄N]The OH solution (15%) was stirred until a homogeneous reaction mixture was formed. The reaction mixture was crystallized in a 25mL Teflon lined autoclave at 170 ℃ for 5 days. The crystallized product Co catalyst is collected by vacuum filtration, washed thoroughly with ethanol and air-dried. And preparing the obtained Co catalyst into a 0.5mM solution, soaking the obtained BVO/CN electrode for 2min, washing with deionized water, and annealing at 350 ℃ for 30min in an inert atmosphere to obtain the BVO/CN/Co photo-anode sensor.

The photoelectric property of the bismuth vanadate photoanode is improved by regulating the carrier transmission process, and the ultrasensitive semiconductor photoelectric nucleic acid tumor marker detection sensor is prepared. In the detection process of the semiconductor photoelectric biosensor, the generation and transfer of photogenerated electrons of the photoelectric material play a main role, and the sensitivity of the photoelectric sensor is determined. The research can improve the photoelectric property of the photoelectric sensor, so that the relation between the generation and transfer of photogenerated electrons and the sensitivity of the semiconductor photoelectric biosensor is explored, and the semiconductor photoelectric biosensor with high sensitivity is obtained. Earlier studies found that the large pi bond can have strong conjugation interaction with the base on single-stranded DNA, so that the large pi bond has strong adsorption capacity on the single-stranded DNA, and has weak binding capacity on the hybridized double-stranded DNA. Therefore, after the II-rich material and the bismuth vanadate material are compounded, the aptamer is adsorbed by using the organic conjugated material, so that the manufacturing cost of the sensor is reduced; the detection limit and sensitivity of the photoelectrochemistry biosensor are researched by further researching different electrochemistry active surface areas, photoelectric properties and the like, and the mechanism of the photoelectrochemistry biosensor is assisted to be researched by a photoelectrochemistry test.

The invention has the following advantages:

(1) in the construction of the BVO/CN/Co photo-anode sensor, the carbon nitride and the Co cocatalyst have a promoting effect on reducing the surface state, improving the carrier concentration and increasing the reactive active sites under the synergistic effect, so that the photoelectric performance of the photo-anode is greatly improved.

(2) The invention uses two II-rich materials to compound BiOV₄The optical anode enables the BVO/CN/Co optical anode to have the best sensing performance.

(3) The invention reduces the manufacturing cost of the sensor by introducing the II-rich material and the bismuth vanadate material for compounding and adsorbing the aptamer by using the organic conjugated material.

Drawings

FIG. 1 is a schematic diagram of the preparation reaction of the present invention;

FIG. 2 is a comparative XRD plot of a series of BVO/CN/Co photoanodes of the present invention;

FIG. 3 is a SEM comparison of a series of BVO/CN/Co photoanodes of the present invention;

FIG. 4 is a comparison of IV of series BVO/CN/Co photoanodes of the present invention;

FIG. 5 is a linear graph of the BVO/CN/Co photoanode sensor of the present invention detecting serotonin.

Detailed Description

The present invention will be described in detail with reference to specific examples. It should be noted that the following examples are only illustrative of the present invention, but the scope of the present invention is not limited to the following examples.

Examples

1. The embodiment relates to a preparation method of a BVO/CN/Co photo-anode sensor, which is shown in a figure 1: the method comprises the following steps:

step 1, preparing a bismuth vanadate substrate:

dissolving 3mmol of bismuth vanadate pentahydrate and 40mmol of sodium iodide in 100ml of ultrapure water, adjusting the pH value of the solution to 1.2 by nitric acid, adding 0.0135mol of ethanol solution of p-benzoquinone, and uniformly stirring to obtain an electrodeposition solution;

a three-electrode system is adopted, a working electrode is cleaned FTO, a counter electrode is a platinum sheet, and a reference electrode is a silver-silver chloride reference electrode; depositing potential is-0.5V, and depositing time is 600 seconds to obtain the bismuth oxyiodide film;

coating 40ul of vanadyl acetylacetonate solution on the bismuth oxyiodide film, drying at 50 ℃, and annealing in a muffle furnace at 450 ℃ for 60 minutes to obtain a bright yellow film;

removing redundant vanadium pentoxide from the bright yellow film in 1M sodium hydroxide solution to obtain a bismuth vanadate film;

step 2, preparation of BVO/CN/Co photo-anode sensor

Ultrasonically dispersing 50mg of carbon nitride powder subjected to two times of thermal oxidation in 150ml of a mixture with a volume ratio of 1: 1, continuously treating for 4 hours with 100 percent of ultrasonic power to obtain milky carbon nitride dispersion liquid;

under the condition of rotating speed of 3000 r/s, 50ul of carbon nitride dispersion liquid is spin-coated on a bismuth vanadate film for 3 times, and heat treatment is carried out for 30 minutes at 250 ℃ to obtain a bismuth vanadate carbon nitride photo-anode (BVO/CN);

and (3) preparing a Co catalyst into a 0.5mM solution, soaking the obtained bismuth vanadate carbon nitride photoanode for 2min, washing the obtained bismuth vanadate carbon nitride photoanode with deionized water, and annealing the obtained bismuth vanadate carbon nitride photoanode for 30min at 350 ℃ in an inert atmosphere to obtain the BVO/CN/Co photoanode sensor.

2. The BVO/CN/Co photo-anode sensor prepared in the example was physically characterized

In order to verify the excellent performance of the BVO/CN/Co photoanode sensor prepared in this example, this example physically characterized the series BVO/CN/Co photoanode sensor in various ways to determine the properties of the prepared photoanode and the changes that occurred therein.

(1) First, the crystal structure of a series BVO/CN/Co photoanode was measured by X-ray diffraction. As can be seen from FIG. 2 (SEM of BVO, BVO/Co, BVO/CN/Co photoanode), the prepared BVO photoanode has a typical monoclinic bismuth vanadate crystal structure, the diffraction peaks of the four samples all correspond to the characteristic peaks of bismuth vanadate and FTO of a conductive substrate, and no new diffraction peak appears after spin coating carbon nitride and self-adsorbing Co promoter. This is because the amount of spin-on carbon nitride and self-adsorbed catalyst is rarely detected.

(2) The crystal structure of a series BVO/CN/Co photoanode was determined by SEM.

FIG. 3 is a SEM comparison of BVO (A), (B) and (C) BVO/Co (C) BVO/CN (D) BVO/CN/Co photoanodes, respectively, and it can be seen from FIG. 3 that the surface of the BVO/Co photoanode is flatter than that of the BVO photoanode, but the introduction of carbon nitride roughens the surface of the BVO/CN and BVO/CN/Co photoanodes.

(3) The crystal structure of the BVO/CN/Co photoanode was determined using a linear sweep voltammetry test.

As can be seen from FIG. 4, the bismuth vanadate photoanode was approximately 1.5mA/cm at 1.23V vs RHE²And the growth of the carbon nitride after spin coating is probably 3mA/cm²After adsorbing the Co catalyst only, the concentration of the catalyst was 3.5mA/cm²The BVO/CN/Co photo-anode can reach 5mA/cm²。

(4) The crystal structure of the BVO/CN/Co photoanode was determined using the linear curve of serotonin.

It can be seen from FIG. 5 that the sensor has a good linear correlation in the range of 0.1fM to 10mM, and the detection of serotonin can be performed by using the sensor.

In the construction of the BVO/CN/Co photo-anode sensor, the carbon nitride and the Co cocatalyst have a promoting effect on reducing the surface state, improving the carrier concentration and increasing the reactive active sites under the synergistic effect, so that the photoelectric performance of the photo-anode is greatly improved; after the II-rich material and the bismuth vanadate material are compounded, the aptamer is adsorbed by using the organic conjugated material, so that the manufacturing cost of the sensor is reduced.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.