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

摘要

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 A mu M 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 x 10(-5) cm(2) s(-1) and 2.20 x 10(4) 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 A mu M), high selectivity, reproducibility and stability.