Polyethylenimine-bridged graphene oxide-gold film on glassy carbon electrode and its electrocatalytic activity toward nitrite and hydrogen peroxide

摘要

Branched polyethylenimine (PEI) was covalently linked to graphene oxide (GO) pre-modified on glassy carbon (GC) electrode (PEI/GO/GC) via an amide bond with 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide/N-hydroxysulfosuccinimide (EDC/NHS) chemistry, and gold nanoparticles was then assembled on the surface of the PEI/GO/GC electrode (Au-PEI/GO/GC) by the electro-reduction of absorbed AuCl_4~- through electrostatic interaction. The Au-PEI/GO/GC electrode exhibited high electrocatalytic activity toward nitrite oxidation and hydrogen peroxide (H_2O_2) reduction. The analytical performances of the Au-PEI/GO/GC electrode demonstrated low detection limit, wider linear range, and good stability for the determination of nitrite and H_2O_2, which make it a promising candidate for amperometric nitrite or enzymeless H_2O_2 sensor.