A novel enzyme-free hydrogen peroxide sensor based on polyethylenimine-grafted graphene oxide-Pd particles modified electrode

• Pd-PEI/GO/GC electrode was constructed by layer-by-layer method.
• The as-prepared Pd-PEI/GO/GC electrode exhibited high electrocatalytic activity toward the reduction of H2O2.
• The Pd-PEI/GO/GC electrode demonstrated high stability for the detection of H2O2.

A novel enzyme-free hydrogen peroxide (H2O2) sensor was fabricated by coating graphene oxide (GO), branched polyethylenimine (PEI) and Pd particles in sequence on the surface of glassy carbon (GC) electrode (Pd-PEI/GO/GC). A layer-by-layer method was used, which involved π–π interactions, covalent bonding through 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide/N-hydroxysulfosuccinimide (EDC/NHSS) chemistry, electrostatic adsorption and electroreduction. The Pd-PEI/GO/GC electrode exhibited high electrocatalytic activity, a low detection limit, and good stability for the detection of H2O2. The sensor’s practical application was tested via determination of H2O2 in real water samples.