A quantitative colorimetric assay of H2O2 and glucose using silver nanoparticles induced by H2O2 and UV

A simple spectrophotometric assay of H2O2 and glucose using Ag nanoparticles has been carried out. Relying on the synergistic effect of H2O2 reduction and ultraviolet (UV) irradiation, Ag nanoparticles with enhanced absorption signals were synthesized. H2O2 served as a reducing agent in the Ag nanoparticles formation in which Ag+ was reduced to Ag by O-2(-) generated via the decomposition of H2O2 in alkaline media. On the other hand, photoreduction of Ag to Ag under UV irradiations also contributed to the nanoparticles formation. The synthesized nanoparticles were characterized by TEM, XPS, and XRD. The proposed method could determine H2O2 with concentrations ranging from 5.0 x 10(-7) to 6.0 x 10(-5) molt L. The detection limit was estimated to be 2.0 x 10(-7) mol/L. Since the conversion of glucose to gluconic acid catalyzed by glucose oxidase was companied with the formation of H2O2, the sensing protocol has been successfully utilized for the determination of glucose in human blood samples. The results were in good agreement with those determined by a local hospital. This calorimetric sensor thus holds great promises in clinical applications. (C) 2013 Jian-Xiu Wang and Liu Deng. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.