▎ 摘　　要

NOVELTY - The method for producing a graphene-polypyrrole electrochemical sensor for detecting a trace amount of lead ions involves (a) dripping concentrated sulfuric acid to graphite powder, dripping potassium permanganate to ice-water bath, dripping dark brown solution to high-purity water, boiling, washing, subjecting purified graphite oxide to dialysis and then freeze-drying, (b) adding pyrrole monomer and sulfuric acid to graphene oxide dispersion, and (c) subjecting the graphene-polypyrrole uniform electrolyte solution to electrochemical reduction. USE - Method is for producing a graphene-polypyrrole electrochemical sensor for detecting a trace amount of lead ions (claimed) in water. ADVANTAGE - The graphene-polypyrrole electrochemical sensor can efficiently detect the trace amount of lead ions with high sensitivity by increasing the spatial binding site and interface electron transport rate of the composite, and can be manufactured by simple and controllable method. DETAILED DESCRIPTION - The method for producing a graphene-polypyrrole electrochemical sensor for detecting a trace amount of lead ions involves (a) preparing solid graphene oxide using improved Hummers chemical method by dripping 98% concentrated sulfuric acid to graphite powder in a mass ratio of 23:1, stirring, dripping potassium permanganate to ice-water bath at 0 degrees C, where the mass ratio of potassium permanganate to graphite powder is 3:1, stirring the resulting mixture, ultrasonically processing the resulting mixture for 5-7 hours to obtain a dark brown solution, dripping the dark brown solution to high-purity water, boiling for 5-15 minutes, adding high-purity water and 30% hydrogen peroxide to terminate the reaction to obtain an aqueous bright yellow graphene oxide solution, centrifuging, carrying out centrifugal washing with dilute hydrochloric acid and high purity water at 8000-1000 rpm to remove impurities, taking out purified graphite oxide, subjecting the purified graphite oxide to dialysis into a dialysis bag for 5-7 days to remove impurities and then freeze-drying to obtain solid graphene oxide, (b) uniformly dispersing the solid graphene oxide in ultrapure water, adding 0.1 M pyrrole monomer and 0.1 M sulfuric acid to 2 mg/ml graphene oxide dispersion, magnetically stirring the mixed solution at room temperature for 3 hours to obtain a graphene-polypyrrole uniform electrolyte solution and then selecting the current time method in the electrochemical workstation using a three electrode system, applying voltage of 0.5 V for 300 seconds, (c) subjecting the graphene oxide-polypyrrole uniform electrolyte solution to electrochemical reduction, performing CV scanning in phosphate-buffered saline buffer at pH of 5.7, a scanning voltage of 0.1 V, a scanning rate of 50 mV/second, an initial voltage of 0 V and a scanning ring number of 20 to obtain graphene-polypyrrole-modified glassy carbon electrode, washing the graphene-polypyrrole-modified glassy carbon electrode with deionized water and then drying at a room temperature to obtain obtaining graphene-polypyrrole electrochemical sensors, and (d) adding lead nitrate having series configuration of 0-750 nM to an acetic acid-sodium acetate buffer solution and then detecting square-wave stripping voltammetry using graphene-polypyrrole electrochemical sensor.