CN110849953A

CN110849953A - Loaded with Cu2O-CuO nanowire array composite material and preparation method thereof, biosensor and application thereof

Info

Publication number: CN110849953A
Application number: CN201911155065.2A
Authority: CN
Inventors: 渠凤丽; 吴静华
Original assignee: Qufu Normal University
Current assignee: Qufu Normal University
Priority date: 2019-11-22
Filing date: 2019-11-22
Publication date: 2020-02-28
Anticipated expiration: 2039-11-22
Also published as: CN110849953B

Abstract

The invention belongs to the field of new nano materials, and particularly relates to Cu loaded copper₂The invention relates to a composite material of O-CuO nanowire array, a preparation method thereof, a biosensor and application thereof₂Nanowire array, annealing in air by precisely controlling time and temperature to obtain three-dimensional Cu-loaded substrate₂The preparation method of the composite material of the O-CuO nanowire array is simple and easy to operate, and CuO can consume Cu in the composite material under illumination₂Electrons on O conduction band, decrease the rate of photon-generated electron-hole recombination, Cu₂The O-CuO nanowire array is used as a three-dimensional electrode, has large surface area, high active site density and low series resistance, is favorable for generating photoelectric signals, and the prepared composite material biosensor is used for detecting tyrosinase.

Description

Loaded with Cu2O-CuO nanowire array composite material and preparation method thereof, biosensor and application thereof

Technical Field

The invention belongs to the field of new nano materials, and particularly relates to Cu loaded copper₂O-CuO nanowire array composite material, preparation method thereof, biosensor and application thereof.

Background

Cu₂O is a p-type semiconductor with a narrow band gap of 2.0-2.2eV and controllable morphology. Due to its advantages in terms of reasonable price, environmental friendliness, abundant reserves and unique optical and electrical properties, etc., it should be usedUsed in many fields, including lithium ion batteries, supercapacitors, CO₂Photocatalytic reduction, photocatalytic degradation, a photoelectric chemical sensor and the like. However, Cu₂O has the disadvantage of high recombination rate of photo-generated electron-hole pairs.

Tyrosinase is a cupreous enzyme, is derived from embryonic nerve kurtosis cells, and is a key enzyme for melanin metabolism and catecholamine. There are many methods for detecting Tyr, such as immunoblotting for detecting Tyr antibody. However, this method is relatively insensitive and cannot be detected quantitatively. The ELISAF method is sensitive to detecting Tyr antibody, but the Tyr of the mushroom is low in homology with the human Tyr.

Disclosure of Invention

In view of the above technical problems, the present invention aims to provide a Cu-supported alloy₂The invention provides a composite material of an O-CuO nanowire array and a preparation method thereof, and also provides a biosensor and application thereof.

The Cu-supported catalyst of the present invention₂Composite material of O-CuO nanowire array, Cu is loaded on foam copper₂And (3) an O-CuO nanowire array.

The Cu-supported catalyst of the present invention₂The preparation method of the O-CuO nanowire array composite material comprises the steps of putting pretreated foamy copper into a mixed solution of a sodium hydroxide solution and an ammonium persulfate solution, standing for reaction, taking out the foamy copper after the reaction, washing and drying to obtain the composite material loaded with Cu (OH)₂Nanowire array of copper foam to be loaded with Cu (OH)₂Placing the copper foam of the nanowire array in a tube furnace for annealing to obtain the Cu-loaded copper₂O-CuO nanowire array composite material.

The pretreatment process of the foamy copper comprises the steps of carrying out ultrasonic treatment for 1-2min by using dilute hydrochloric acid, wherein the concentration of the dilute hydrochloric acid is 1 mol/mL.

The concentration of the sodium hydroxide solution is 4-6 mol/mL.

The concentration of the ammonium persulfate solution is 0.2-0.3 mol/mL.

The annealing process comprises the following steps: at 2-5 deg.C for min^-1The temperature is raised to 450 ℃ at the temperature raising rate, and the temperature is kept for 10-20 min.

And (3) dropwise adding the chitosan solution to the surface of the composite material, and drying at room temperature to obtain the chitosan composite material, wherein the concentration of the chitosan solution is 0.2-0.5 wt%.

The biosensor is applied to photoelectrochemical detection of tyrosinase, the biosensor is placed in an incubation liquid for incubation for 0.5-2.5 hours, the incubation liquid is a mixed liquid of the tyrosinase, the tyrosine and deionized water, the incubation liquid can enhance a photocurrent signal of the biosensor, and the concentration of the tyrosinase in the incubation liquid during detection has a linear relation with the photocurrent intensity generated by the biosensor.

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

(1) The invention takes foam copper as a substrate and prepares Cu (OH) by a room-temperature solvothermal method₂Nanowire array, annealing in air by precisely controlling time and temperature to obtain three-dimensional Cu-loaded substrate₂The preparation method of the composite material of the O-CuO nanowire array is simple and easy to operate;

(2) cu-loaded prepared by the invention₂In the composite material of O-CuO nanowire array, CuO can consume Cu under illumination₂Electrons on O conduction band, decrease the rate of photon-generated electron-hole recombination, Cu₂The O-CuO nanowire array is used as a three-dimensional electrode, has larger surface area, high active site density and low series resistance, and is beneficial to generating photoelectric signals;

(3) the invention provides a biosensor based on a prepared composite material, which is used for detecting tyrosinase, wherein the photocurrent of the biosensor has a linear relation with the concentration of the tyrosinase, the lower limit of the detection of the tyrosinase is 0.023U/mL when S/N is 3, and the biosensor has good selectivity during detection.

Drawings

FIG. 1 shows Cu-supported catalyst prepared in example 1₂O-CuO nanowire array composite (Cu)₂O/CuO NA/CF) experimental schematic diagram for detecting Tyr;

FIG. 2 shows Cu (OH) prepared in example 1₂Scanning electron microscopy of nanowire arrays;

FIG. 3 shows Cu prepared in example 1₂Scanning electron microscope for O-CuO nanowire arrayA drawing;

FIG. 4A is a curve showing the variation of photocurrent intensity with the concentration of Tyr, and B is a calibration curve corresponding thereto;

FIG. 5 is a graph showing the selectivity of the sensor for Tyr detection prepared in example 2.

Detailed Description

The invention is further illustrated by the following examples and figures of the specification.

Example 1

(1) Taking the foam copper, and cutting the foam copper into 2 x 4cm by using a pair of scissors²Then sonicated with dilute hydrochloric acid for 1-2 minutes. Washing the copper foam sheet with deionized water, weighing 3.204g of sodium hydroxide by using an analytical balance, dissolving in 15mL of water, weighing 0.89g of ammonium persulfate, dissolving in 15mL of water, mixing the dissolved sodium hydroxide solution with the ammonium persulfate solution, putting the copper foam sheet subjected to ultrasonic treatment by using dilute hydrochloric acid into the mixed solution, standing for reaction for 20min, taking out the copper foam sheet after the reaction is finished, washing the copper foam sheet with deionized water, and drying the copper foam sheet by using an oven to obtain the Cu-loaded copper₂A composite of O-CuO nanowire arrays;

(2) loading Cu obtained in the step (1)₂Placing the composite material of the O-CuO nanowire array into a tube furnace for annealing, wherein the annealing process is carried out at 2 ℃ for min^-1Heating to 350 ℃ at the heating rate, and keeping the temperature for 15min to obtain the Cu-loaded₂O-CuO nanowire array composite material.

Example 2

The composite material obtained in example 1 was cut to 0.5 x 1.0cm²The sheet of (1) was fixed with a raw tape to an area of 0.5 x 0.5cm². 0.25 wt% chitosan solution was added dropwise to a fixed area of Cu using a 50 μ L format pipette₂And drying the O-CuO nanowire array at room temperature to obtain an electrode, and putting the electrode into a 2mL centrifugal tube containing 100 muL Tyr, 100 muL tyrosine and 100 muL deionized water for incubation for 1.5h to obtain the signal-enhanced biosensor for detecting Tyr.

FIG. 1 shows the preparation of a composite material (Cu)₂O/CuO NA/CF) for detecting Tyr. As shown in the figure, a three-dimensional Cu is synthesized₂O-CuO nanowire array composite material. Because the chitosan hasGood adhesiveness, after chitosan is dripped, the chitosan can be adhered to Cu₂The surface of the electrode of the O-CuO nanowire array. Cu deposition of chitosan₂And placing the O-CuO nanowire array in an incubation liquid of Tyr and tyrosine for incubation. According to Cu₂Band diagram of O-CuO, Cu under light₂The photo-generated electrons on the Conduction Band (CB) of O can be transferred to CB of CuO. As the chitosan has a plurality of amino structures, 1, 2-benzoquinone or derivatives thereof generated by Tyr catalyzing tyrosine are covalently connected with amino, and the amino is used as an electron acceptor to consume a photogenerated carrier, and a photogenerated hole of CuO is transferred to Cu₂Valence band of O, and then to the substrate, thereby realizing Cu₂And the separation of the O-CuO photo-generated electron-hole pairs enhances the photocurrent signals. And thus can be used to detect Tyr;

FIG. 2 shows Cu (OH)₂Scanning electron micrograph of nanowire array from which Cu (OH) can be observed₂The nano wires cover the whole foam copper;

FIG. 3 is Cu₂Scanning electron microscope image of O-CuO nanowire array, from which Cu can be observed₂The O-CuO nanowire array covers the whole copper foam;

fig. 4A is a graph showing the change in photocurrent intensity with the Tyr concentration, and fig. 4B is a calibration curve corresponding thereto. As shown in the figure, as the Tyr concentration increases from 0U/mL to 10U/mL, the generated photocurrent also linearly increased. Fig. 4B is an interpolation graph corresponding to a calibration curve, and the linear regression equation is that y is 53.793x +170.517 (R)²0.993), where y (μ a) is the photocurrent signal and x (U/mL) is the concentration of Tyr; the lower detection limit is 0.023U/mL when the S/N is 3;

FIG. 5 is a graph showing the selectivity of the sensor for Tyr detection prepared in example 2. By detecting relatively high concentrations of potentially interfering substances, for example: bovine Serum Albumin (BSA), trypsin, alkaline phosphatase (ALP), glucose oxidase (GOx), glucose, thrombin, zinc ion (Zn)²⁺) Potassium ion (K)⁺) We can see this Cu₂The PEC response signal of the O-CuO nanowire array is strongest, which indicates that the PEC enzyme biological analysis method has good selectivity.

Claims

1. Loaded with Cu₂The composite material of the O-CuO nanowire array is characterized in that: cu is loaded on the foam copper₂And (3) an O-CuO nanowire array.

2. The Cu-supported catalyst according to claim 1₂The preparation method of the composite material of the O-CuO nanowire array is characterized by comprising the following steps: putting the pretreated foamy copper into a mixed solution of a sodium hydroxide solution and an ammonium persulfate solution, standing for reaction, taking out the foamy copper after the reaction, washing and drying to obtain the loaded Cu (OH)₂Nanowire array of copper foam to be loaded with Cu (OH)₂Placing the copper foam of the nanowire array in a tube furnace for annealing to obtain the Cu-loaded copper₂O-CuO nanowire array composite material.

3. Cu-loaded according to claim 2₂The preparation method of the composite material of the O-CuO nanowire array is characterized by comprising the following steps: the pretreatment process of the foamy copper comprises the steps of carrying out ultrasonic treatment for 1-2min by using dilute hydrochloric acid, wherein the concentration of the dilute hydrochloric acid is 1 mol/mL.

4. Cu-loaded according to claim 2₂The preparation method of the composite material of the O-CuO nanowire array is characterized by comprising the following steps: the concentration of the sodium hydroxide solution is 4-6 mol/mL.

5. Cu-loaded according to claim 2₂The preparation method of the composite material of the O-CuO nanowire array is characterized by comprising the following steps: the concentration of the ammonium persulfate solution is 0.2-0.3 mol/mL.

6. Cu-loaded according to claim 2₂The preparation method of the composite material of the O-CuO nanowire array is characterized by comprising the following steps: the annealing process comprises the following steps: at 2-5 deg.C for min^-1The temperature is raised to 450 ℃ at the temperature raising rate, and the temperature is kept for 10-20 min.

7. The Cu-supported catalyst according to claim 1₂O-CuO nanowire arrayThe biosensor prepared from the composite material is characterized in that: and (3) dropwise adding the chitosan solution to the surface of the composite material, and drying at room temperature to obtain the chitosan composite material, wherein the concentration of the chitosan solution is 0.2-0.5 wt%.

8. Use of a biosensor as claimed in claim 7, wherein: the method is applied to photoelectrochemical detection of tyrosinase.

9. Use of a biosensor according to claim 8, wherein: and placing the biosensor in an incubation liquid for incubation for 0.5-2.5h, wherein the incubation liquid is a mixed liquid of tyrosinase, tyrosine and deionized water, and the incubation liquid can enhance the photocurrent signal of the biosensor.

10. Use of a biosensor according to claim 9, wherein: the concentration of tyrosinase in the incubation liquid has a linear relationship with the photocurrent intensity generated by the biosensor.