The graphene nanosheets/manganese oxide nanoparticles modified glassy carbon electrode (GC/GNSs/MnOx) was simply prepared by casting a thin film of GNSs on the GC electrode surface, followed by performing electrodeposition of MnOx at applied constant potential. The GC/GNSs/MnOx modified electrode shows high catalytic activity toward oxidation of l-cysteine. Hydrodynamic amperometry determination of l-cysteine gave linear responses over a concentration range up to 120 mM with a detection limit of 75 nM and sensitivity of 27 nAmM_1. The GC/GNSs/ MnOx electrode appears to be a highly efficient platform for the development of sensitive, stable and reproducible l-cysteine electrochemical sensors.
