Electrochemical detection of hydrogen peroxide based on silver nanoparticles via amplified electron transfer process

Abstract

A simple electrochemical sensor platform for hydrogen peroxide (H2O2) using silver nanoparticles (Ag NPs) entrenched in silicate matrix (APS(SG)) is reported. The redox molecules such as potassium ferricyanide ([Fe(CN)6]3−), methyl viologen (MV2+) and ruthenium hexamine ([Ru(NH3)6]3+) were utilized to investigate the electron transfer behavior of the APS(SG)–Ag NPs. The glassy carbon (GC) electrode modified with amine-functionalized silicate sol–gel matrix (GC/APS(SG)) exhibited a complete suppression of the electrochemical response toward MV2+ and [Ru(NH3)6]3+. However, GC/APS(SG) electrode displayed a twofold increase in the peak currents and fast electron transfer kinetics toward [Fe(CN)6]3− in comparison with GC electrode, suggesting that GC/APS(SG) electrode demonstrated an excellent anion exchange property. The GC electrode modified with APS(SG)–Ag NPs (GC/APS(SG)–Ag NPs) showed an improved electron transfer kinetics when neither positive nor negative charge of the electroactive species in the electrolyte. The GC/APS(SG)–Ag NP electrode was effectively further applied for the electrocatalytic and sensor applications toward H2O2. The present sensor exhibited the reduction of H2O2 at less negative potential and showed the experimental low detection limit of 25.0 µM with the sensitivity of 0.042 µA/µM. In addition, the developed APS(SG)–Ag NP-based amperometric sensor presented fast response, good stability and reproducibility.