An ultra-sensitive non-enzymatic hydrogen peroxide sensor based on SiO2-APTES supported Au nanoparticles modified glassy carbon electrode

Abstract A novel electrochemical sensor based on (3-aminopropyl)triethoxysilane (APTES) functionalized SiO2 supported Au nanoparticles and Nafion (Nf) as the protective membrane was fabricated for the electrochemical determination of H2O2 in contact lens-cleaning solution. The modification steps of glassy carbon working electrode (GCE) were evaluated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The amperometric results showed that Nf/Au@SiO2-APTES/GCE sensor can be used to determine H2O2 in contact lens solutions with the linear ranges of 14–180 μM and 0.18–7.15 mM, excellent sensitivities of 2514.6 and 894.2 μA mM cm−2, and a low limit of detection (LOD) of 4.25 μM depending upon signal-to-noise ratio of 3. Nf/Au@SiO2-APTES/GCE exhibited excellent repeatability with relative standard deviation (RDS) of 2.66% and acceptable reproducibility with RSD of 3.35%. The sensor displayed reasonable selectivity in the presence of uric acid, dopamine, ascorbic acid, glucose, mannose, glycine, fructose, histidine, and arginine with RSD less than 2.5%. The fabricated Nf/Au@SiO2-APTES/GCE sensor has been successfully applied to detect H2O2 in contact lens cleaning solutions.