▎ 摘　　要

NOVELTY - Preparation of gold-doped nitrogen-reduced graphene oxide-gold-palladium nanocatalyst involves adding chloroauric acid, potassium tetrachloropalladate(II) and graphene oxide to an alkaline solution of xanthine, then adding ascorbic acid, heating at 50-70 degrees C, heat preserving for 30-90 minutes, dripping hydrazine hydrate, continuously heat preserving for 30-90 minutes, washing and separating. USE - The method is useful for preparing gold-doped nitrogen-reduced graphene oxide-gold-palladium nanocatalyst for electrochemical sensor, which is useful for detection of chrysophanol (all claimed). ADVANTAGE - The nanocatalyst has excellent electrochemical activity, and can realize the detection of chrysophanol according to the linear detection range of 1.84-84.5 mu g/ml and detection limit of 0.58 mu g/ml. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) an electrochemical sensor, which comprises the nanocatalyst modified glassy carbon electrode; and (2) an electrochemical detection method of chrysophanol, which involves crushing rhubarb containing medicinal materials to obtain a medicinal material powder, dissolving the medicinal material powder in ethanol and ultrasonically extracting to obtain a medicinal material extraction solution, and detecting the obtained solution by the electrochemical sensor.