▎ 摘　　要

NOVELTY - Electrochemically detecting trace amounts of melamine comprises taking graphite, adding sodium nitrate, cold concentrated sulfuric acid, potassium permanganate and deionized water, heating, adding deionized water, and hydrogen peroxide solution, allowing to stand, washing lower solution, coating on the treated glassy carbon electrode, soaking in dithiothreitol, washing, coating gold nanoparticle solution, naturally drying, soaking in L-cysteine solution and detecting electrical signal of different concentrations melamine. USE - The method is useful for electrochemically detecting trace amounts of melamine (claimed). ADVANTAGE - The method is simple and has high stability. DETAILED DESCRIPTION - Electrochemically detecting trace amounts of melamine comprises (i) taking 0.5-3 g graphite (325 mesh), adding 1-3 g sodium nitrate under ice water bath condition, adding 20-50 ml cold concentrated sulfuric acid, stirring at 350 revolutions/minute for 30-60 minutes, adding 2-5 g potassium permanganate for 2-4 hours, removing ice bath, heating to 30-50 degrees C, stirring for 30-60 minutes, adding 150-300 ml deionized water, heating to 98 degrees C, stirring for 15-30 minutes, and adding 100-200 ml deionized water, and hydrogen peroxide solution, allowing to stand, discarding supernatant and washing lower solution with distilled water until neutral, (ii) taking 1-5 ml 0.01% chloroauric acid solution, adding 50-200 ml deionized water and 1-5 ml 1% sodium citrate aqueous solution and heating at 100 degrees C for 10-60 minutes to obtain red wine gold nanoparticles (AuNPs) solution, (iii) taking glassy carbon electrode, polishing with alumina powder, washing with acetone, ethanol and distilled water for 10 minutes and drying, (iv) coating 1 mg/ml graphene oxide on the treated glassy carbon electrode, soaking in 50 mmol/l dithiothreitol in ethanol for 12 hours, washing with distilled water, coating gold nanoparticle solution, naturally drying at room temperature and soaking in 20 mmol/l L-cysteine solution for 12 hours, and (v) taking different concentrations of melamine in acetic acid solution, adding 0.2 M pH 5.8-8 phosphate or borate buffer solution and detecting electrical signal using electrode as a working electrode.