Synthesis of au nanoparticles supported on functionalized silica gel for amperometric determination of hydrogen peroxide in contact lens solution

In this study, a new nanocomposite based on (3-aminopropyl)triethoxysilane (APTES) functionalized SiO2 supported Au nanoparticles (Au@SiO2-APTES) was achieved for electroanalytical determintion of H2O2 in contact lens solution. Nafion (Nf) was performed as a protective membrane. The electrochemical properties of GCE modified with Au@SiO2-APTES and SiO2-APTES were evaluated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and amperometry. X-ray diffraction (XRD), transmission electron microscopy (TEM), and fourier transform infrared spectroscopy (FTIR) were used for characterization of the nanocomposites. The obtained Nf/Au@SiO2-APTES/GCE sensor exhibited two linear determination ranges for H2O2. The first one was 14-180 µM and the second one was 0.18-7.15 mM. The limit of detection (LOD) and sensitivities of the sensor were calculated to be 4.25 µM, 2514.6 µA mM-1 cm-2 and 894.2 µA mM-1 cm-2, respectively. The sensor showed excellent selectivity for H2O2. Also, H2O2 was successfully detected in contact lens solution using Nf/Au@SiO2-APTES/GCE.