Electrochemical sensing platform for hydrogen peroxide determination at low reduction potential using silver nanoparticle-incorporated bentonite clay

Abstract

Abstract: The electrocatalytic activity of silver nanoparticle-incorporated bentonite clay (Ag-Bt) for hydrogen peroxide (H2O2) reduction is investigated in 0.1 M pH 7.0 phosphate buffer solution. Ag-Bt material-coated glassy carbon (GC) electrode displays high electrocatalytic activity for H2O2 reduction with increased current response in comparison with GC/Bt electrode. The catalytic current increases linearly with incremental addition of H2O2 from 10 µM to 5.0 mM (based on the amperometric experiments at an applied potential −0.3 V). The apparent diffusion coefficient for H2O2 and catalytic rate constant for H2O2 reduction at the GC/Ag-Bt platform are calculated to be 2.3 × 10−5 cm2 s−1 and 2.20 × 104 M−1 s−1, respectively. The practical application using the Ag-Bt material is shown for the determination of H2O2 in real sample. The GC/Ag-Bt platform exhibits low detection limit (9.1 µM), high selectivity, reproducibility and stability. Graphical abstract: [Figure not available: see fulltext.] © 2015, Springer Science+Business Media Dordrecht.