▎ 摘　　要

NOVELTY - A cysteine determination method involves reducing graphene oxide by dopamine as a reducing agent for reducing chloroauric acid to generate nano-gold. Sulfydryl of the cysteine is reacted with nano-gold through a gold-sulfur bond and dopamine on the surface of the graphene through a Michael addition reaction. The cysteine detection is performed according to the change of the current signal after the nano-gold/graphene composite material is modified on the surface of an electrode. USE - Method for determining cysteine based on nanometer gold/graphene nano-composite. ADVANTAGE - The method enables determining cysteine with strong identifying property, high detection sensitivity and better selectivity in a simple and quick manner.