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

• Au-PEI/GO/GC electrode was constructed by layer-by-layer method.
• The as-prepared Au-PEI/GO/GC electrode exhibited high elcctrocatalytic activity toward nitrite and hydrogen peroxide.
• The Au-PEI/GO/GC electrode showed good analytical performances for the determination of nitrite and hydrogen peroxide.

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 AuCl4− through electrostatic interaction. The Au-PEI/GO/GC electrode exhibited high electrocatalytic activity toward nitrite oxidation and hydrogen peroxide (H2O2) 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 H2O2, which make it a promising candidate for amperometric nitrite or enzymeless H2O2 sensor.

A novel Au-PEI/GO/GC electrochemical sensor, constructed by layer-by-layer method in four steps including π–π interaction, covalently bonding via EDC/NHS chemistry, electrostatic adsorption, and electro-reduction, was demonstrated for the analysis of nitrite and hydrogen peroxide. The sensor showed high stability due to the strong interaction between each layer.Figure optionsDownload as PowerPoint slide