▎ 摘　　要

NOVELTY - Constructing aptamer sensorusing nano-gold/zinc oxide-graphene composite material involves utilizing indium tin oxide as the base electrode, followed by ultrasonic cleaning with acetone, ethanol and ultrapure water for 30 min, and nitrogen purging to dry. The clean indium tin oxide conductive glass is immersed in 0.2 mg/ml graphene oxide. In the solution, the constant current deposition method is used. The current density was 0.25 mA/cm2, and the deposition time is 100 s. An indium tin oxide modified electrode uniformly supported by reduced graphene oxide (rGO) is prepared. The above modified electrode is immersed In a 0.02 mol/l zinc nitrate aqueous solution, in a constant temperature water bath at 80 degrees C, a constant potential of minus 1.4 V is deposited for 30 minutes to prepare a zinc oxide-reduced graphene oxide /indium tin oxide modified electrode. USE - Method for constructing aptamer sensor using nano-gold/zinc oxide-graphene composite material as photoelectric sensitive element. ADVANTAGE - The method improves the signal stability, and have higher sensitivity and lower detection limit. DETAILED DESCRIPTION - Constructing aptamer sensorusing nano-gold/zinc oxide-graphene composite material involves utilizing indium tin oxide as the base electrode, followed by ultrasonic cleaning with acetone, ethanol and ultrapure water for 30 min, and nitrogen purging to dry. The clean indium tin oxide conductive glass is immersed in 0.2 mg/ml graphene oxide. In the solution, the constant current deposition method is used. The current density was 0.25 mA/cm2, and the deposition time is 100 s. An indium tin oxide modified electrode uniformly supported by reduced graphene oxide (rGO) is prepared. The above modified electrode is immersed In a 0.02 mol/l zinc nitrate aqueous solution, in a constant temperature water bath at 80 degrees C, a constant potential of minus 1.4 V is deposited for 30 minutes to prepare a zinc oxide-reduced graphene oxide /indium tin oxide modified electrode. The zinc oxide-reduced graphene oxide /indium tin oxide electrode is immersed in 2.0 mmol/l in a mixed solution of chloroauric acid and 0.5 mol/l potassium chloride, the photoelectrode gold/zinc oxide-reduced graphene oxide/indium tin oxide is prepared by reduction at minus 0.4 V constant potential for 50 s. The aptamer sensor is prepared by taking 20 mu L of 1.0 mu mol/l thiol pre-modified aptamer solution, drop it on the surface of the photoelectrode gold/zinc oxide-reduced graphene oxide/indium tin oxide, incubating at room temperature and humidity for 2 h, self-assembling on the surface of the photoelectrode through the Au-S covalent bond, dropwise adding 20 mu L 0.2 mmol/l mercaptopropionic acid (MPA) as a blocking agent and incubating for 30 minutes to seal the active adsorption sites on the surface of the photoelectrode. The structure of double-stranded deoxyribonucleic acid is formed, and the modified electrode is obtained. 20 mu l of 10.0 mu mol/l methylene blue (MB) solution is taken and applied on the surface of indium tin oxide, methylene blue as photosensitizer is combined with dsDNA through intercalation or electrostatic bonding to obtain aptamer sensor.