High-sensitivity non-enzymatic glucose sensor and preparation method thereof

[0027] The preparation of embodiment 1 gold @ bovine serum albumin

[0028] A. Slowly drop 10 ml of chloroauric acid solution with a concentration of 10 mmol/L into the stirring 10 ml of bovine serum albumin solution with a concentration of 5 mg/mL, and stir for 5 min.

[0029] B. Slowly add sodium hydroxide solution with a concentration of 0.2 mol/L dropwise, adjust the pH value to 12, and stir for 1 min.

[0030] C. Quickly add 50 mg of ascorbic acid and stir for 5 min.

[0031] D. Centrifuge the fully reacted solution at 8000r/min for 10min, wash the precipitate with deionized water and centrifuge, repeat the washing and centrifugation twice, finally prepare 10ml of deionized water, disperse the centrifuged sediment and seal it, As for aging at about 4°C low temperature for 24h, for use, gold@bovine serum albumin solution was obtained.

[0032] Example 2 Preparation of high-sensitivity non-enzymatic glucose sensor

[0033] A. Using fluorine-doped tin oxide conductive glass as the base, the size is 25×8×1.1mm. Take 10 μL of the prepared gold@bovine serum albumin solution and drop it on the fluorine-doped tin oxide glass to form a circular droplet with a diameter of about 5 mm.

[0034] B. Dry the fluorine-doped tin oxide conductive glass with droplets at 50°C until the droplets are completely dried, forming a dark blue circular film.

[0035]C. The fluorine-doped tin oxide conductive glass dried in the previous step is calcined at a high temperature of 400° C. for 2 hours, and after cooling to room temperature, the film exhibits an obvious golden yellow color. So far, the preparation of a high-sensitivity non-enzymatic glucose sensor of the present invention is completed.

[0036] Embodiment 3 Detection experiment

[0037] The detection experiment was carried out on a CHI600E electrochemical workstation and a three-electrode system. The working electrode was the high-sensitivity non-enzymatic glucose sensor of the present invention, the counter electrode was a platinum wire electrode, and the reference electrode was a saturated calomel electrode. First, activate the sensor in sulfuric acid with a concentration of 0.1mol/L, that is, scan the cyclic voltammetry curve. The starting and ending voltages are 0V and 1.5V, respectively, and the cycle is repeated for more than 20 cycles, so that the adjacent two curves almost overlap. activation. Then, the performance of the sensor of the present invention was characterized by the single-potential step chronoamperometry. Under the action potential of 0.15V, glucose was continuously added to the test bottom solution, and the current time curves at different concentrations were measured, as shown in the following figure: figure 1 , figure 2 and image 3 shown. Finally, according to the above three time-current time curves, it can be found that the high-sensitivity non-enzymatic glucose sensor of the present invention has three different linear ranges, such as Figure 4 shown. The standard curves of glucose concentration and response current in the three linear ranges are as follows: Figure 5 0.1~1mmol/L shown, the sensitivity is 330.002μA/mmol/cm 2; Image 6 1~8mmol/L shown, the sensitivity is 103.786μA/mmol/cm 2; Figure 7 8~34mmol/L shown, the sensitivity is 53.738μA/mmol/cm 2. The goodness of fit R of the three-segment regression equation 2 were 0.998, 0.997, and 0.998, respectively, and the detection limit was 3.6 μmol/L.