▎ 摘　　要

NOVELTY - A photoelectric chemical sensor preparing method involves adding sulfuric acid and fuming nitric acid into a reaction bottle, and preparing oxidized graphene solid. The oxidized graphene solid is added into water to obtain graphene oxide solution, followed by dipping indium titanium oxide glass in poly(diallyldimethyl ammonium chloride) solution containing sodium chloride, coating with graphene oxide solution, and drying to obtain electrode, and preparing enzyme reaction solution. The electrode is immersed in the enzyme reaction solution, and washed. The electrode photocurrent is measured. USE - Method for preparing a photoelectric chemical sensor that is utilized in detecting alkaline phosphatase and tyrosinase. ADVANTAGE - The method enables preparing the photoelectric chemical sensor with increased photocurrent, better selectivity and high sensitivity. DETAILED DESCRIPTION - A photoelectric chemical sensor preparing method involves adding 17.5 mL concentrated sulfuric acid and 5.4 mL fuming nitric acid into a reaction bottle to obtain a mixture. The mixture is cooled at 0 degrees C, and stirred uniformly with 1 g graphite raw material to avoid agglomeration. The resultant mixture is added with a certain amount of potassium chlorate for 0.5 hours. The mixture is stirred at room temperature for a period of time until the reaction is completed. The stirred mixture is added with large amount of de-ionized water to dilute. The diluted mixture is filtered until the filtrate pH is neutral. The filtrate is dried in vacuum to obtain oxidized graphene solid. The oxidized graphene solid is added into deionized water ultrasonically to obtain graphene oxide solution, followed by dipping pre-treated indium titanium oxide glass in 2% poly(diallyldimethyl ammonium chloride) solution containing 0.5 mol/L sodium chloride, washing with de-ionized water for 10 minutes, coating with 25 mu L to 0.5 mg/mL graphene oxide solution, and naturally drying to obtain graphene oxide modified indium titanium oxide electrode, adding 250 mu L of 0.01 mol/L Tris-HCl buffer solution at a constant pH, 30 mu L of 1 mmol/L alkaline phosphatase or tyrosinase substrate, 20 mu L different concentrations of alkaline phosphatase or tyrosinase to 96 well microtiter plate, mixing at room temperature for 20-40 minutes to obtain enzyme reaction solution. The graphene oxide modified indium titanium oxide electrode is immersed in the enzyme reaction solution to react for 5 minutes. The electrode is washed with 0.01 mol/L Tris-HCl buffer solution having the pH of 7.8. The electrode is placed at 7.8 pH in a Tris-HCl buffer solution at an electrode potential of -0.2 V with relative to the silver/silver chloride reference electrode. The electrode photocurrent is measured on a self-made photoelectric chemical apparatus.