阅读说明：本技术 一种基于铜基纳米复合结构的便携式微型葡萄糖无酶传感电极及其制备方法与应用 (It is a kind of based on the portable minisize glucose of copper-based nano composite construction without enzyme sensing electrode and the preparation method and application thereof ) 是由 奚亚男 胡淑锦 于 2019-08-19 设计创作，主要内容包括：本发明提供了一种基于铜基纳米复合结构的便携式微型葡萄糖无酶传感电极及其制备方法与应用。本专利提供了一种基于多孔铜和氧化铜的复合材料的高效传感电极,可兼具铜的良好导电性能与氧化铜的优异催化性能,电极采用三电极共面体系,电极尺寸与USB尺寸匹配,形成微型传感电极,可直接与电化学工作站连接。本发明提供的NCA/NPC复合电极具有较高的灵敏度,极低的检出限,较宽的检出范围以及优异的稳定性和抗干扰性能,在0.5～5.0mM的检出范围内其灵敏度为1621μA/mM·cm<Sup>2</Sup>,检出限为338nM,响应时间小于3s,可应用于人体血糖的实际检测。(The present invention provides a kind of based on the portable minisize glucose of copper-based nano composite construction without enzyme sensing electrode and the preparation method and application thereof.This patent provides a kind of efficient sensing electrode of composite material based on Porous Cu and copper oxide, the excellent conductive performance of copper and the excellent catalytic performance of copper oxide can be had both, electrode uses the coplanar system of three electrodes, electrode size is matched with USB size, micro sensing electrode is formed, can directly be connect with electrochemical workstation.NCA/NPC combination electrode sensitivity with higher provided by the invention, extremely low detection limit, wider inspection range and excellent stability and interference free performance, its sensitivity is 1621 μ A/mMcm in the inspection range of 0.5~5.0mM 2 , detect and be limited to 338nM, the response time is less than 3s, can be applied to the actually detected of blood sugar for human body.)

1. it is a kind of based on the portable minisize glucose of copper-based nano composite construction without enzyme sensing electrode, which is characterized in that it is described Electrode is made of electrode basement, buffer layer, conversion zone；The electrode base materials can be ceramics, silicon wafer, high molecular material Deng；The electrode basement is equipped with the buffer layer, and the buffer-layer surface is equipped with the conversion zone；The buffer layer is copper Layer；The conversion zone is cupric oxide nano coral array/nano porous copper；The electrode by three electrodes integrate it is coplanar form, Middle working electrode surface modifies cupric oxide nano coral array/nano porous copper, to electrode face finish platinum, reference electrode surface Modify silver-silver chloride；The working electrode and the distance to electrode are 50~100 μm.

2. according to claim 1 a kind of electric without enzyme sensing based on the portable minisize glucose of copper-based nano composite construction Pole, which is characterized in that the nano porous copper has three-dimensional continuous poriferous structure, and reaction bore dia is 100~300nm, ligament Width is 100~500nm, and porosity is 70~80%；The nanoporous copper layer thickness is 3.0~3.3 μm.

3. according to claim 1 a kind of electric without enzyme sensing based on the portable minisize glucose of copper-based nano composite construction Pole, which is characterized in that the cupric oxide nano coral array is evenly distributed on the nano porous copper layer surface, nanometer rods list First diameter is 40~100nm, length is 200~400nm.

4. it is a kind of based on the portable minisize glucose of copper-based nano composite construction without the preparation method of enzyme sensing electrode, feature It is, comprising the following steps:

(1) standard integrate three electrodes to platinum plating on electrode；

(2) silver-silver chloride is modified on the reference electrode that standard integrates three electrodes；

(3) electric deposited copper floor on the working electrode that standard integrates three electrodes；

(4) in working electrode front deposited Au tin alloy, then metallic tin is removed, obtains the electrode of modification nano porous copper；

(5) working electrode is aoxidized in aqueous slkali, obtains the nanoporous of surface modification cupric oxide nano coral array Copper electrode.

5. according to claim 4 a kind of electric without enzyme sensing based on the portable minisize glucose of copper-based nano composite construction The preparation method of pole, it is characterised in that: in the step (1), platinum plating bath group becomes H₂PtCl₆1mM and KCl 0.1M.

6. according to claim 4 a kind of electric without enzyme sensing based on the portable minisize glucose of copper-based nano composite construction The preparation method of pole, it is characterised in that: in the step (2), plate the solution composition of silver-silver chloride are as follows: silver nitrate 40g/L~ It is 45g/L, sodium thiosulfate 200g/L~250g/L, potassium metabisulfite 40g/L~45g/L, ammonium acetate 20g/L~30g/L, thio Semicarbazides 0.6g/L~0.8g/L；Electroplating temperature is 25 DEG C, current density 0.3A/dm², the time is 15~20min.

7. according to claim 4 a kind of electric without enzyme sensing based on the portable minisize glucose of copper-based nano composite construction The preparation method of pole, it is characterised in that: in the step (3), the composition of copper electroplating liquid are as follows: Cu₂P₂O₇·3H₂O 65g/L、 K₄P₂O₇·3H₂O 380g/L、C₆H₅O₇(NH₄)₃ 23g/L、C₆H₈O₇0.5g/L；The temperature of electro-coppering is 35 DEG C, current density For 2.0A/dm², time 300s.

8. according to claim 4 a kind of electric without enzyme sensing based on the portable minisize glucose of copper-based nano composite construction The preparation method of pole, it is characterised in that: in the step (4), the composition of copper-tin alloy plating solution used in electro-deposition are as follows: Cu₂P₂O₇· 3H₂18~20g/L of O, Sn₂P₂O₇15~16g/L, K₄P₂O₇·3H₂250~300g/L of O, K₂HPO₄·3H₂70~90g/L of O, H₃PO₄3.5~4.0g/L.

9. according to claim 4 a kind of electric without enzyme sensing based on the portable minisize glucose of copper-based nano composite construction The preparation method of pole, it is characterised in that: in the step (4), electrodeposition temperature is 20 DEG C~28 DEG C, current density 0.8A/ dm²~1.2A/dm², the time is 800~1000s.

10. it is according to claim 4 it is a kind of based on the portable minisize glucose of copper-based nano composite construction without enzyme sense The preparation method of electrode, it is characterised in that: in the step (4), removal metallic tin is the corrosive liquid used using chemical corrosion method For acid solution, removing alloy temperature is 70 DEG C, time 900min.

11. it is according to claim 4 it is a kind of based on the portable minisize glucose of copper-based nano composite construction without enzyme sense The preparation method of electrode, it is characterised in that: in the step (5), the composition of aqueous slkali are as follows: (NH₄)₂S₂O₈ 0.1M、NaOH 0.3M；Reaction temperature is 10 DEG C, time 600s.

Technical field

The invention belongs to glucose detection sensor field, the copper-based nano for being related to a kind of no enzyme detection glucose is compound The application of the preparation method of structure mini sensing electrode, especially sensing electrode in glucose quickly detects.

Background technique

A kind of simple and important monosaccharide of glucose, it can be recycled in mankind's body in the form of blood glucose, blood appropriate Sugared concentration helps to promote memory and cognitive performance, and blood sugar concentration is too low, will lead to the diseases such as hypoglycemia or insulin shock Shape, blood sugar concentration is excessively high, will lead to fat or diabetes.Diabetes are one of most common diseases in the whole world, in recent decades, The disease incidence of diabetes constantly rises, and has been cited as one of four big non-communicable diseases.Diabetes are a kind of chronic diseases, can be drawn Multiple complications such as hypopsia, renal failure, retinopathy and apoplexy etc. are sent out, the effective detection and treatment to diabetes By society extensive concern, therefore, develop efficient stable glucose sensor be very it is necessary to.

Detecting the main method of glucose at this stage includes electrochemical method, colorimetric method, conductance method, optical means and fluorescence Spectroscopic methodology, wherein electrochemical process has many advantages, such as that detection limit is low, the response time is short, stability is good and cost is relatively low, therefore obtains It is widely used.

It is dense to detect glucose to be generally basede on glucose oxidase (GOD) for electrochemical glucose sensor on the market at present Degree, but this enzyme is easy inactivation in immobilization process, and the sensing electrode based on enzyme is difficult to keep good stability and again Existing property, it is therefore necessary to research and develop a kind of glucose sensing electrodes of no enzyme detection.

Possess at present building enzyme-free glucose sensing electrode material have monometallic (Pt, Au, Cu etc.) and alloy (Pt-Pd, Pt-Au etc.), these noble metal processing costs are high, it is therefore necessary to develop a kind of efficient stable and low-cost material is made For the base material of no enzyme sensing electrode.

Patent CN107991371A discloses a kind of copper oxide non-enzymatic glucose electrochemical sensor, main technical schemes It is to utilize easy preparation method synthesis transition metal oxide copper oxide nano material, highly sensitive with building, wide detection model Enclose and low cost copper oxide non-enzymatic glucose electrochemical sensor.The standby CuO/GCE electrode of patent system has excellent selection Property, glucose can be detected under the interference of the substances such as ascorbic acid.However, this method needs to prepare at high temperature, and process conditions Complexity, preparation cost is higher, is unfavorable for industrialization.

In conclusion this field needs, a kind of preparation process is simple, reusable enzyme-free glucose quickly detects Sensing electrode simplifies detecting step to reduce preparation cost, so that glucose detection is more efficient, stablizes.

Summary of the invention

The object of the present invention is to provide a kind of portable minisize grapes coplanar based on copper-based nano composite construction, three electrodes Sugar is without enzyme sensing electrode.

The electrode is made of electrode basement, buffer layer, conversion zone；Electrode basement is equipped with buffer layer, and buffer-layer surface is set There is conversion zone；Buffer layer is layers of copper；Conversion zone is cupric oxide nano coral array/nano porous copper.Electrode is integrated by three electrodes Coplanar composition, wherein working electrode surface modifies cupric oxide nano coral array/nano porous copper, to electrode face finish platinum, Reference electrode surface modification silver-silver chloride；Working electrode and be 50~100 μm to the distance of electrode.

The electrode solve the problems, such as three-electrode system can not be applied to microsensor, and interdigital electrode obtained due to It working electrode and is closer between electrode, the concentration polarization in Electrochemical Test Procedure can be substantially eliminated.

Nano porous copper prepared by the present invention has three-dimensional continuous structure, and thickness can reach 3.0~3.3 μm, it is possible to increase electricity Ultimate ratio surface area increases electrode active surface site, electrode catalyst performance is substantially improved, it is 100 that nanostructure, which reacts bore dia, ~300nm, ligament width are 100~500nm, and porosity is 70~80%, are evenly distributed, the growth for subsequent oxidation copper provides Enough holes and surface.

For nano porous copper prepared by the present invention after peroxidating, surface can grow that diameter is 40~100nm, length is The coralliform copper oxide array of 200~400nm, each cupric oxide nano-rod surface on each array are all covered with coarse Grain, further enriches the surface texture of material.

NCA/NPC composite electrode layers prepared by the present invention are the composite construction of copper oxide and copper, combine copper oxide to Portugal The high catalytic activity of grape sugar and the high charge transporting of copper, the catalysis suitable for glucose sense.

It is a further object of the present invention to provide a kind of portable minisizes coplanar based on copper-based nano composite construction, three electrodes Preparation method of the glucose without enzyme sensing electrode.

It is provided by the invention based on the portable minisize glucose of copper-based nano composite construction without the preparation of enzyme sensing electrode Method, specifically includes the following steps:

(1) standard integrate three electrodes to platinum plating on electrode；

(2) silver-silver chloride is modified on the reference electrode that standard integrates three electrodes；

(3) electric deposited copper floor on the working electrode that standard integrates three electrodes；

(4) in working electrode front deposited Au tin alloy, then metallic tin is removed, obtains the electricity of modification nano porous copper Pole；

(5) working electrode is aoxidized in aqueous slkali, obtains the nanometer of surface modification cupric oxide nano coral array Porous copper electrode.

Sensing electrode prepared by the present invention uses three-electrode system, therefore to electrode face finish platinum, in reference electrode Surface modification silver-silver chloride.

In step (1) of the present invention, the preferred neutral soluble salt of the supporting electrolyte of plating solution can increase the ionic conductance of plating solution Rate.Platinum plating bath group becomes H₂PtCl₆1mM and KCl 0.1M.

In step (2) of the present invention, the solution composition of silver-silver chloride is plated are as follows: silver nitrate 40g/L~45g/L, sodium thiosulfate 200g/L~250g/L, potassium metabisulfite 40g/L~45g/L, ammonium acetate 20g/L~30g/L, thiosemicarbazide 0.6g/L~ 0.8g/L；Electroplating temperature is 25 DEG C, current density 0.3A/dm², the time is 15~20min.

Sensing electrode prepared by the present invention has multi-layer metal structure, in electrode basement electroplating surface layers of copper as buffering Layer, can effectively promote the binding force of electro-deposition copper and tin and substrate, improve the stability of electrode.

In step (3) of the present invention, the composition of copper electroplating liquid are as follows: Cu₂P₂O₇·3H₂O 65g/L、K₄P₂O₇·3H₂O 380g/ L、C₆H₅O₇(NH₄)₃ 23g/L、C₆H₈O₇0.5g/L；The temperature of electro-coppering is 35 DEG C, current density 2.0A/dm², the time is 300s。

Because of the process characteristic that the electro-deposition of Cu-Sn has speed fast, at low cost, the present invention selects copper-tin alloy as system The presoma of standby nano porous copper.

The nano porous copper of suitable performance in order to obtain needs to carry out a large amount of experiment screening to the electroplate liquid of electro-deposition, The concentration of main salt, the process conditions of electro-deposition and complexing agent, additive can influence the property of copper and tin coating in plating solution.If plating The ratio of stannous pyrophosphate is too low in liquid, then is difficult to form the continuous porous pattern with higher porosity, if its ratio mistake Height, the group branch for forming porous framework is difficult to support three-dimensional porous structure because content is too low, so as to cause material binding force It is too poor.

In step (4) of the present invention, the composition of copper-tin alloy plating solution used in electro-deposition are as follows: Cu₂P₂O₇·3H₂18~20g/ of O L、Sn₂P₂O₇15~16g/L, K₄P₂O₇·3H₂250~300g/L of O, K₂HPO₄·3H₂70~90g/L of O, H₃PO₄3.5~ 4.0g/L；Preferably, Cu₂P₂O₇·3H₂O 19g/L、Sn₂P₂O₇ 15.6g/L、K₄P₂O₇·3H₂O 280g/L、K₂HPO₄·3H₂O 80g/L、H₃PO₄ 3.95g/L。

When acid copper tin alloy, the too high or too low copper and tin coating surface that will lead to of current density is coarse and uneven, Current density reduction causes Theil indices to decline, and causes the hole of Porous Cu small and lacks, current density is excessively high, leads to Theil indices It improves, causes dissolution component excessive, maintain rock-steady structure after being unfavorable for alloy.

In step (4) of the present invention, electrodeposition temperature is 20 DEG C~28 DEG C, preferably 25 DEG C；Current density is 0.8A/dm² ~1.2A/dm², preferably 1.0A/dm²；Time is 8001000s；Preferably 900s.

When copper-tin alloy removes alloy, the present invention uses acid reagent, although also can achieve removal tin using alkaline reagent Purpose, such as use the mixed solution of alkali and hydrogen peroxide, but Cu can be generated in solution simultaneously²⁺, so that hydrogen peroxide decomposes rapidly, make At the uncontrollable of rate of dissolution, while the oxygen for decomposing generation can damage the fine porous structure of generation, so that Decorative layer short texture, and be easy to remove with basal layer.

In step (4) of the present invention, removal metallic tin is using chemical corrosion method, and corrosive liquid used is acid solution, goes alloy temperature Degree is 70 DEG C, time 900min.

After nano porous copper is aoxidized in alkaline solution, the coralloid copper oxide of nanometer can be obtained on its surface Array.The formation of coralloid nano array is related with the reaction time, with the extension of oxidization time, nano porous copper it is smooth tough Band is gradually coarse, and gradually appears Rod-like shape, further extends when the time, and nano porous copper surface will form a large amount of nanometer rods Structure, sustained response then will form coralloid nano array.Nanometer rods are evenly distributed on electrode surface, finally obtain nanoporous The composite construction of copper and surface coralliform array.

However reaction time process, the NCA/NPC decorative layer being prepared will easily fall off from electrode basement, therefore select Select suitable oxidation time.

In step (5) of the present invention, the composition of aqueous slkali are as follows: (NH₄)₂5₂O₈0.1M,NaOH 0.3M；Reaction temperature is 10 DEG C, time 600s.

It is a further object of the present invention to provide a kind of based on the portable minisize glucose of copper-based nano composite construction without enzyme The application method of sensing electrode.

The present invention by high performance nano-porous materials in conjunction with interdigital electrode, by the interdigitated electrode structure of small spacing, Ohmmic drop is reduced, concentration polarization is slowed down, enhances signal-to-noise ratio, greatly improves the performance of enzyme-free glucose sensing electrode.

Nanoporous decorative layer prepared by the present invention is the composite construction of copper oxide and copper, combines copper oxide to glucose High catalytic activity and copper high charge transporting, suitable for glucose catalysis sense.

In alkaline solution, the copper oxide on NCA/NPC combination electrode surface can be oxidized to CuOOH reactive intermediate, to After glucose is added dropwise in electroplate liquid, glucose can be oxidized to gluconic acid by CuOOH reactive intermediate, in NCA/NPC compound electric The pole surface electro-catalysis process glycoxidative to grape is mediated by Cu (II)/Cu (III) redox.Cu (III) can fill When electronics transfer mediator.

Therefore, in alkaline solution, the NCA/NPC combination electrode mechanism glycoxidative to grape are as follows:

CuO+OH^-→CuOOH+e^-

CuOOH+glucose+e^-→CuO+glucose acid

NCA/NPC combination electrode sensitivity with higher provided by the invention, extremely low detection limit, wider detection model It encloses and excellent stability and interference free performance, its sensitivity is 1621 μ A/mM in the inspection range of 0.5~5.0mM cm², detect and be limited to 338nM, the response time is less than 3s.

The beneficial effects of the present invention are:

(1) three electrode coplanar structure: the copolymerization of three electrodes is integrated in same electrode plane, and constant distance, passes through fork Refer to the design of electrode structure, effectively reduces the spacing between electrode, reduce solution itself ohmmic drop, slow down concentration polarization, favorably In the conduction of electronics, the sensitivity of electrode is enhanced；Electrode can directly be connect with electrochemical workstation, convenient to use, can Realize instant data transmission.

(2) without enzyme stable detection: modifying working electrode using NCA/NPC, combine copper oxide and be catalyzed to the height of glucose The high charge transporting of activity and Porous Cu greatly improves electrode detection performance, while equally distributed by nanostructure Hole improves electrode specific surface area and porosity, so that electrode catalyst performance is stronger and performance is stablized, and realizes glucose No enzyme detection, it is with good stability.

Detailed description of the invention

Invention is described further using attached drawing, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention, For those of ordinary skill in the art, without creative efforts, it can also be obtained according to the following drawings Its attached drawing.

Fig. 1 be it is prepared by the present invention based on the portable minisize glucose of copper-based nano composite construction without enzyme sensing electrode Schematic diagram；

The scanning electron microscope (SEM) photograph (a) and the coralliform copper oxide battle array after nano porous copper oxidation 100s that Fig. 2 is nano porous copper Column scan electron microscope (b)；

Fig. 3 is NCA/NPC combination electrode and copper oxide modified electrode prepared by the present invention to 0mM glucose (I) and the Portugal 2mM The cyclic voltammetry curve figure of grape sugar (II)；

Fig. 4 is that 2mM glucose is added in NCA/NPC combination electrode prepared by the present invention in 0.1M KOH buffer, not Cyclic voltammetry curve figure under same sweep speed (10~100mV/s)；

Fig. 5 is the grape that various concentration is added in NCA/NPC combination electrode prepared by the present invention in 0.1M KOH buffer Cyclic voltammetry curve figure after sugared (0.0~5.0mM), scanning speed 100mV/s；

Fig. 6 is that NCA/NPC combination electrode prepared by the present invention is continuously added to glucose (0.5 in 0.1M KOH buffer ~5.0mM) ladder response signal graph figure；

Fig. 7 is that glucose (0.0 is continuously added dropwise in 0.1M KOH buffer in NCA/NPC combination electrode prepared by the present invention ~10.0mM) chronoa mperometric plot figure.

Specific embodiment

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

It is a kind of based on the portable minisize glucose of copper-based nano composite construction without the preparation method of enzyme sensing electrode, specifically The following steps are included:

(1) standard integrate three electrodes to platinum plating on electrode；

(2) silver-silver chloride is modified on the reference electrode that standard integrates three electrodes；

(3) electric deposited copper floor on the working electrode that standard integrates three electrodes；

(4) in working electrode front deposited Au tin alloy, then metallic tin is removed, obtains the electricity of modification nano porous copper Pole；

(5) working electrode is aoxidized in aqueous slkali, obtains the nanometer of surface modification cupric oxide nano coral array Porous copper electrode.

Further, in step (1), platinum plating bath group becomes H₂PtCl₆1mM and KCl 0.1M.

Further, in step (2), the solution composition of silver-silver chloride is plated are as follows: silver nitrate 40g/L~45g/L, thiosulfuric acid Sodium 200g/L~250g/L, potassium metabisulfite 40g/L~45g/L, ammonium acetate 20g/L~30g/L, thiosemicarbazide 0.6g/L~ 0.8g/L；Electroplating temperature is 25 DEG C, current density 0.3A/dm², the time is 15~20min.

Further, in step (3), the composition of copper electroplating liquid are as follows: Cu₂P₂O₇·3H₂O 65g/L、K₄P₂O₇·3H₂O 380g/ L、C₆H₅O₇(NH₄)₃ 23g/L、C₆H₈O₇0.5g/L；The temperature of electro-coppering is 35 DEG C, current density 2.0A/dm², the time is 300s。

Further, in step (4), the composition of copper-tin alloy plating solution used in electro-deposition are as follows: Cu₂P₂O₇·3H₂18~20g/ of O L、Sn₂P₂O₇15~16g/L, K₄P₂O₇·3H₂250~300g/L of O, K₂HPO₄·3H₂70~90g/L of O, H₃PO₄3.5~ 4.0g/L；Preferably, Cu₂P₂O₇·3H₂O 19g/L、Sn₂P₂O₇ 15.6g/L、K₄P₂O₇·3H₂O 280g/L、K₂HPO₄·3H₂O 80g/L、H₃PO₄ 3.95g/L。

Further, in step (4), electrodeposition temperature is 20 DEG C~28 DEG C, preferably 25 DEG C；Current density is 0.8A/dm² ~1.2A/dm², preferably 1.0A/dm²；Time is 8001000s；Preferably 900s.

Further, in step (4), removal metallic tin is using chemical corrosion method, and corrosive liquid used is acid solution, goes alloy temperature Degree is 70 DEG C, time 900min.

Further, in step (5), the composition of aqueous slkali are as follows: (NH₄)₂S₂O₈0.1M,NaOH 0.3M；Reaction temperature is 10 DEG C, time 600s.

The contents of the present invention are described in further detail below by way of specific embodiment.