Preparation method of glucose sensing device based on MXene-Au compound electrochemistry

Abstract

The invention aims to solve the problems of sensitivity, stability and the like of an existing electrochemical sweat sensor, and provides a preparation method of a glucose sensing device based on MXene-Au compound electrochemistry. The sensor has the main characteristics of simple preparation process, high sensitivity, high stability and the like, and can meet the requirements of real-time sweat monitoring in various occasions. The preparation method of the electrochemical glucose sensing device comprises the following steps: casting an MXene-Au nanocomposite on the surface of a working electrode, modifying the electrode by using glucose oxidase, packaging a layer of Nafion on the surface of the electrode to prepare a glucose sensing electrode, and assembling the glucose sensing electrode with a medical adhesive tape and a cotton fabric to obtain the electrochemical glucose sensing device. The required electrochemical glucose sensing device is obtained. The glucose sensor can be directly attached to the surface of the human skin to continuously monitor the personal glucose level in real time, and the action of a wearer cannot be interrupted or limited. The electrochemical glucose sensing device lays a foundation for noninvasive wearable monitoring of blood glucose of diabetic patients.

Description

Technical Field

[0001] The invention relates to a method for preparing a glucose sensor device based on MXene-Au composite electrochemistry, and belongs to the field of composite materials. Background Art

[0002] Diabetes is a multi-etiology metabolic disease characterized by high blood sugar levels, which can cause many serious complications, including stroke, blindness, and heart disease. The most common way to test blood sugar is with a self-testing blood glucose meter, which relies on painful fingertip blood sampling. Due to the good correlation between blood sugar and sweat glucose, many non-invasive wearable electrochemical sweat sensors have demonstrated their feasibility in continuous monitoring of sweat glucose. Electrochemical detection can convert target analyte information into measurable electrical signals in real time. To this end, biological receptor (such as enzyme) molecules are usually immobilized on the surface of conductive electrode materials to selectively interact with target molecules. At the same time, electrochemical detection methods have the characteristics of low cost, directness, and portability, which are more advantageous than other detection methods (colorimetry, fluorescence). Summary of the invention

[0003] The problem to be solved by the present invention is to provide a method for preparing a glucose sensor device based on MXene-Au composite electrochemistry in view of the problems of sensitivity and stability of existing electrochemical sweat sensors. The main features of the sensor are simple preparation process, high sensitivity, high stability, etc., which can meet the needs of real-time monitoring of sweat in various occasions. The preparation method of the electrochemical glucose sensor device in the present invention is: first, drop-casting MXene-Au nanocomposite on the surface of the working electrode, then modifying the electrode with glucose oxidase, and finally encapsulating a layer of Nafion on the surface of the electrode to prepare a glucose sensing electrode, assembling it with medical tape and cotton fabric to obtain the required electrochemical glucose sensor device. The present invention can be directly attached to the surface of human skin to continuously and in real time monitor personal glucose levels without interrupting or restricting the wearer's movements. The electrochemical glucose sensor device lays the foundation for non-invasive wearable monitoring of blood glucose in diabetic patients.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] (1) Preparation of MXene-Au nanocomposites: In the presence of MXene, gold nanoparticles (AuNPs) were synthesized by directly reducing tetrachloroauric acid (III) trihydrate (HAuCl4·3H2O) to obtain MXene-Au nanocomposites, which were then centrifuged, washed with water, and freeze-dried to obtain MXene-Au powders.

[0006] (2) Preparation of precursor solution: The MXene-Au powder prepared above is dispersed in deionized water and mixed with an appropriate amount of Nafion, and ultrasonically mixed to obtain a suspension containing single-layer or few-layer structured MXene-Au nanosheets;

[0007] (3) Electrode functionalization: Take the MXene-Au suspension prepared in (2) and drop it onto the surface of the working electrode (WE). Then drop the glucose oxidase (GOx) solution onto the WE, and finally encapsulate a layer of Nafion to prevent the effective substance from falling off;

[0008] (4) Assembly of sensor device: A piece of medical tape of a specific size, a sensing electrode and cotton fabric are assembled to make a simple glucose sensor device.

[0009] Preferably, in step (1), the concentration of MXene is 0.1-5 mg / ml, the concentration of HAuCl4·3H2O is 2-20 mM, the reaction time is 10-60 min, and the number of water washings is 2-8 times.

[0010] Preferably, in step (2), the concentration of the MXene-Au suspension is 0.1-10 mg / ml, the concentration of Nafion is 0.1-1 wt%, and the ultrasonic time is 10-60 min.

[0011] Preferably, in step (3), the amount of MXene-Au suspension is 2-20 μL, the concentration of GOx solution is 20-80 mg / ml, the amount is 1-10 μL, the concentration of Nafion solution is 0.1-1 wt%, and the amount is 0.5-5 μL.

[0012] The above technical solution has the following beneficial effects:

[0013] (1) MXene has outstanding characteristics such as large specific surface area, excellent conductivity and hydrophilicity. Embedding gold nanoparticles can significantly regulate MXene and improve its conductivity and electrochemical properties. At the same time, MXene with a unique accordion structure can inhibit irreversible aggregation and improve the chemical stability of AuNPs;

[0014] (2) The present invention uses MXene-Au nanocomposite as the electrode matrix material. The synergistic effect between the two different components enhances the electrochemical signal, and the gold nanostructure allows the enzyme (protein) activity to be maintained during adsorption, so that the sensing interface has a higher sensitivity.

[0015] (3) The electrochemical glucose sensor device based on MXene-Au composite prepared in the present invention has excellent properties such as portability, high sensitivity and good stability, and its preparation method is simple and the cost is low.

[0016] (4) The electrochemical glucose sensor device prepared by the present invention shows broad application prospects in the fields of real-time human motion monitoring, medical health testing, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0018] Figure 1 : It is the result diagram of Example 1 in the present invention.

[0019] Figure 2 : It is the result diagram of Example 2 in the present invention.

[0020] Figure 3 : It is the result diagram of Example 3 in the present invention. DETAILED DESCRIPTION

[0021] The present invention is described below in conjunction with the accompanying drawings and specific embodiments. Unless otherwise specified, the technical means used in the present invention are methods known to those skilled in the art. In addition, the embodiments should be understood as illustrative rather than limiting the scope of the present invention, and the essence and scope of the present invention are limited only by the claims. For those skilled in the art, various changes or modifications to the material composition and dosage in these embodiments, without departing from the essence and scope of the present invention, also belong to the protection scope of the present invention.

[0022] Example 1: Taking advantage of the excellent reducibility and active surface of MXene, HAuCl4·3H2O was directly reduced without adding any reducing agent or stabilizer to synthesize gold nanoparticles and obtain MXene-Au nanocomposites. Figure 1 Shown is the SEM image of MXene-Au nanocomposite.

[0023] Example 2: A suspension containing a single-layer or few-layer structured MXene-Au nanosheet is drop-cast onto a working electrode, and after drying, a layer of GOx solution is drop-cast to obtain MXene-Au / GOx / SPCE. Figure 2 Shown is the SEM image of the MXene-Au / GOx / SPCE working electrode surface.

[0024] Example 3: In order to evaluate the performance of the prepared MXene-Au / SPCE material in electron transfer, the MXene-Au / SPCE was tested in a solution containing 5 mM [Fe(CN)6] 3- / 4- Cyclic voltammetry curves at different scan rates in 0.1M KCl. Figure 3 As shown, it shows a clear reversible redox peak pair, which is consistent with Fe 3+ / Fe 4+The redox probe is associated with the redox peak current, and as the scan rate increases, the redox peak current also increases accordingly.

Claims

1. A method for preparing a glucose sensor device based on MXene-Au composite electrochemistry, comprising the following steps: (1) Preparation of MXene-Au nanocomposites: In the presence of MXene, gold nanoparticles (AuNPs) were synthesized by directly reducing tetrachloroauric acid (III) trihydrate (HAuCl4·3H2O) to obtain MXene-Au nanocomposites, which were then centrifuged, washed with water, and freeze-dried to obtain MXene-Au powders. (2) Preparation of precursor solution: The MXene-Au powder prepared above is dispersed in deionized water and mixed with an appropriate amount of Nafion, and ultrasonically mixed to obtain a suspension containing single-layer or few-layer structured MXene-Au nanosheets; (3) Electrode functionalization: Take the MXene-Au suspension prepared in (2) and drop it onto the surface of the working electrode (WE). Then drop the glucose oxidase (GOx) solution onto the WE, and finally encapsulate a layer of Nafion to prevent the effective substance from falling off; (4) Assembly of sensor device: A piece of medical tape of a specific size, a sensing electrode and cotton fabric are assembled to make a simple glucose sensor device.

2. The method for preparing a glucose sensor device based on MXene-Au composite electrochemistry according to claim 1, characterized in that: In the above step (1), the concentration of MXene is 0.1-5 mg / ml, the concentration of HAuCl4·3H2O is 2-20 mM, the reaction time is 10-60 min, and the number of water washings is 2-8 times.

3. The method for preparing a glucose sensor device based on MXene-Au composite electrochemistry according to claim 1, characterized in that: In the above step (2), the concentration of the MXene-Au suspension is 0.1-10 mg / ml, the concentration of Nafion is 0.1-1 wt%, and the ultrasonic time is 10-60 min.

4. The method for preparing a glucose sensor device based on MXene-Au composite electrochemistry according to claim 1, characterized in that: In the above step (3), the amount of MXene-Au suspension is 2-20 μL, the concentration of GOx solution is 20-80 mg / ml, the amount is 1-10 μL, the concentration of Nafion solution is 0.1-1 wt%, and the amount is 0.5-5 μL.

Images