Dual enzyme-like properties of silver nanoparticles decorated Ag2WO4 nanorods and its application for H2O2 and glucose sensing

Abstract

The facile one-pot hydrothermal synthesis of silver nanoparticles decorated silver tungstate nanorods (Ag@Ag2WO4 NRs) and their catalytic activities similar to those of natural enzymes catalase and peroxidase were reported. The Ag@Ag2WO4 NRs could catalyze the decomposition reaction of H2O2 into water and oxygen besides catalyzing the reduction of H2O2 into water in the presence of peroxidase substrates. Spectrophotometric and electrochemical methods were used to investigate the pH-dependent dual enzyme mimics exhibited by Ag@Ag2WO4 NRs. The Ag@Ag2WO4 NRs showed a lower Km value when compared to the natural horseradish peroxidase enzyme showing the stronger affinity for hydrogen peroxide and TMB. The peroxidase-like property of the synthesized Ag@Ag2WO4 NRs was exploited to develop a H2O2 sensor with a broad linear range and low detection limit. Thus, a wide linear range of 45.4 μM- 2.38 mM and a low detection limit of 5.4 μM was obtained by spectrophotometry while a wide linear range of 62.34 μM- 2.4 mM and a low detection limit of 6.25 μM was obtained by amperometry for H2O2. Further, the detection method was extended for the detection of glucose with a wide linear range of 27.7 μM- 0.33 mM and a low detection limit of 2.6 μM. © 2020 Elsevier B.V.