Graphene oxide functionalized with silver@silica-polyethylene glycol hybrid nanoparticles for direct electrochemical detection of quercetin

A direct electrochemical detection of quercetin based on functionalized graphene oxide modified on gold-printed circuit board chip was demonstrated in this study. Functionalized graphene oxide materials are prepared by the covalent reaction of graphene oxide with silver@silica-polyethylene glycol nanoparticles (~12.35 nm). Functionalized graphene oxide electrode shows a well-defined voltammetric response in phosphate buffered saline and catalyzes the oxidation of quercetin to quinone without the need of an enzyme. Significantly, the functionalized graphene oxide modified electrode exhibited a higher sensitivity than pristine gold-printed circuit board and graphene oxide electrodes, a wide concentration range of 7.5 to 1040 nM and detection limit of 3.57 nM. Developed biosensor platform is selective toward quercetin in the presence of an interferent molecule.