▎ 摘　　要

NOVELTY - An aptamer biosensor manufacturing method involves dispersing graphene oxide in ultrapure water and carrying out ultrasonic dispersion. Poly(sodium styrene sulfonate) is reacted with hydrazine hydrate, and the resulting black dispersion is washed and dried to obtain graphene-chitosan complex. Gold nanoparticles are prepared by boiling chlorauric acid and sodium citrate solution. Homogeneous aptamer solution is applied on surface of graphene-chitosan-modified glassy carbon electrode followed by dropping gold nanoparticles, drying, fixing aptamers to electrode surface and drying. USE - Method for manufacturing aptamer biosensor used for detecting malachite green in aquatic product. ADVANTAGE - The method enables manufacturing aptamer biosensor with high sensitivity. The biosensor ensures simple and fast detection of malachite green. DETAILED DESCRIPTION - An aptamer biosensor manufacturing method involves dispersing 0.02 g graphene oxide in 20 ml ultrapure water and carrying out ultrasonic dispersion for 8 hours. Poly(sodium styrene sulfonate) is reacted with 0.5 ml hydrazine hydrate at 90 degrees C with stirring for one day, and the resulting black dispersion is washed and dried to obtain graphene-chitosan complex. Gold nanoparticles are prepared by boiling 100 ml 0.01% chlorauric acid and 2ml 1% sodium citrate solution. An aptamer solution is prepared by dissolving an aptamer in 0.1% sterile diethylpyrocarbonate. 10 mu l homogeneous aptamer solution is applied on surface of graphene-chitosan-modified glassy carbon electrode at room temperature followed by dropping 10 mu l gold nanoparticles, drying at room temperature, fixing aptamers to the electrode surface and drying at room temperature. An INDEPENDENT CLAIM is also included for a method for detecting malachite green, which involves taking silver/silver chloride as electrical reference electrode, platinum as a counter electrode and aptamer biosensor as working electrode, connecting working electrode to electrochemical workstation, providing potassium ferricyanide solution, applying scanning potential of 0.5 V, detecting signal variation using plotted curve and detecting malachite green according to plotted calibration curve.