▎ 摘　　要

NOVELTY - A cadmium and lead dications electrochemically measuring method involves selecting graphene oxide, controlling temperature of the graphene oxide with hydrazine, and reducing graphene oxide chemically to obtain a graphene-modified electrode. The graphene-modified electrode is polymerized with L-cysteine. The cadmium dications and lead dications are measured electrochemically with the L-cysteine-graphene-modified electrode as working electrode, silver-silver chloride electrode as reference electrode and platinum wireas three-electrode system. USE - Method for measuring cadmium dications and lead dications electrochemically in water. ADVANTAGE - The method enables measuring cadmium dications and lead dications electrochemically in water at same time in a real-time and environment-friendly manner with high sensitivity and selectivity. DETAILED DESCRIPTION - A cadmium dications and dications electrochemically measuring method involves selecting graphene oxide as raw material, controlling temperature of the graphene oxide with hydrazine and reaction time, and reducing the graphene oxide chemically to obtain graphene-modified electrode with nanosheet structure. The graphene-modified electrode is polymerized with L-cysteine to obtain L-cysteine-graphene-modified electrode. The cadmium dications and lead dications are measured electrochemically with the L-cysteine-graphene-modified electrode as working electrode, silver-silver chloride electrode as a reference electrode and platinum wireas three-electrode system in CHI660B electrochemical workstation. The graphene-modified electrode is prepared by obtaining graphene oxide, mixing the graphene oxide with chitosan ultrasonically and uniformly in certain volume ratio to obtain stable solution, adding 5-6 drops of the obtained solution on a clean glass carbon electrode surface and drying the electrode naturally to obtain graphene oxide-modified electrode. The graphene oxide-modified electrode is immersed in hydrazine hydrate at 60-70 degrees C and heated in water bath for 8 hours to obtain graphene-modified electrode. The graphene-modified electrode is immersed in 1x 10-3 mol/l L-cysteine and phosphate buffered saline (PBS) with pH of 7 and scanned with cyclic voltammetry at scanning speed of 100 mV/second. The electrode is washed with PBS to obtain L-cysteine-graphene modified electrode.