Fabrication of a novel hydrogen peroxide biosensor based on the AuNPs–C@SiO2 composite

The composite of C@SiO2 with gold nanoparticles (AuNPs–C@SiO2) was fabricated by layer-by-layer assembly technique and was used to fabricate a novel hydrogen peroxide (H2O2) biosensor. The composite was composed of a colloidal carbon sphere core with an average diameter of 200 nm and a porous silica shell with a uniform thickness of about 50 nm, and decorated with gold nanoparticles on the surface. The porous silica shell could promote the composite to show high bio-compatibility and chemical stability. The AuNPs–C@SiO2 composite combined with hemoglobin (Hb) was used to construct a novel biosensor for the determination of H2O2, displaying a wide linear range from 5.0 to 80 μM with a detection limit of 0.08 μM at 3σ. The Kmapp value for the biosensor was determined to be 71.49 μM.