▎ 摘　　要

NOVELTY - Complex modified electrode comprises graphene modified glassy carbon electrode and in situ loaded on the surface of the graphene modified glassy carbon electrode by electrochemical deposition and nano-cobalt oxide modified layer. USE - The complex modified electrode is useful for detecting lead in livestock and poultry drinking water (claimed). DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing electrode comprising (i) ultrasonic cleaning glassy carbon electrode to obtain the glassy carbon electrode substrate, drying, (ii) absorbing 10 mu l graphene oxide dispersion solution, drying, adding 0.1 mol/l potassium chloride olution at room temperature, by cyclic voltammetry, scanning 20 circles in the -1.5 to 0.5V voltage range to 100 mV/s to form reduced graphene, taking out and using distilled water to obtain the graphene modified glassy carbon electrode, (iii) adding the obtained the graphene modified glassy carbon electrode in a three electrode system into cobalt chloride solution containing 1 mmol/l phosphate buffer liquid, scanning 30 circles to form nano cobalt, adding double distilled water and taking out.