Amperometric glucose sensor based on enhanced catalytic reduction of oxygen using glucose oxidase adsorbed onto core-shell Fe3O4@silica@Au magnetic nanoparticles

Monodisperse Fe3O4 magnetic nanoparticles (NPs) were prepared under facile solvothermal conditions and successively functionalized with silica and Au to form core/shell Fe3O4@silica@Au NPs. Furthermore, the samples were used as matrix to construct a glucose sensor based on glucose oxidase (GOD). The immobilized GOD retained its bioactivity with high protein load of 3.92 × 10− 9 mol·cm− 2, and exhibited a surface-controlled quasi-reversible redox reaction, with a fast heterogeneous electron transfer rate of 7.98 ± 0.6 s− 1. The glucose biosensor showed a broad linear range up to 3.97 mM with high sensitivity of 62.45 μA·mM− 1 cm− 2 and fast response (less than 5 s).

Core-shell structured Fe3O4@silica@Au nanoparticles were prepared and used as matrix to construct an amperometric glucose sensor based on glucose oxidase, which showed broad linear range, high sensitivity, and fast response.Figure optionsDownload as PowerPoint slideHighlights
► Synthesis of monodispersed Fe3O4 nanoparticles.
► Fabrication of core/shell Fe3O4@silica@Au nanoparticles.
► Construction of a novel glucose sensor with wide linear range, high sensitivity and fast response.