A Hydrogen Peroxide Sensor Based on Silver Nanoparticles Biosynthesized by Bacillus subtilis

In this study, silver nanoparticles (AgNPs) were biosynthesized by Bacillus subtilis and used to construct a nonenzymatic hydrogen peroxide (H2O2) sensor. Scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy confirmed that the AgNPs were prepared successfully with spherical morphology. The electrochemical properties of the resulted sensor were investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. It was found that the sensor exhibited good electrocatalytic activity towards H2O2 reduction with a wider linear range from 0.05 to 120 mmol center dot L-1, a detection limit of 8 mu mol center dot L-1 and a fast response time less than 2 s. The sensor exhibited good selectivity for H2O2 determination in the presence of glucose, acetaminophen, ascorbic acid and uric acid.