▎ 摘　　要

NOVELTY - An electrochemical sensor preparing method involves dispersing oxidized graphene in water, adding ethylenediamine/ethanol solution into agitated graphene oxide by stirring, washing the mixture with ethanol/water, vacuum drying, and grinding to obtain diamine modified graphene oxide nano material, weighing ethylene diamine modified graphene oxide nano material, adding water by ultrasonic treatment to obtain diamine modified graphene oxide nano material suspension. The ethylenediamine modified graphene nanomaterial suspension is applied on surface of glassy carbon working electrode and dried. USE - Method for preparing electrochemical sensor for detecting maleic hydrazide. ADVANTAGE - The method enables preparing the electrochemical sensor with strong selectivity, in rapid and simple manner. DETAILED DESCRIPTION - An electrochemical sensor preparing method involves dispersing 0.2-0.3 g oxidized graphene in 30 mL ultra pure water, adding 1-2 mL/35 mL ethylenediamine/ethanol solution dropwise into the agitated graphene oxide by stirring at room temperature for 24 hours, after finishing reaction, washing the mixture with ethanol/water, vacuum drying at 60 degrees C for 24 hours, taking out and grinding to obtain diamine modified graphene oxide nano material, weighing 2.5-10 mg ethylene diamine modified graphene oxide nano material, adding 5 mL super-pure water by ultrasonic treatment for 3 minutes to obtain diamine modified graphene oxide nano material suspension. The 4-8 mu L of ethylenediamine modified graphene nanomaterial suspension is applied on the surface of glassy carbon working electrode, and dried to obtain finished product.