Au@Ag nanostructures for the sensitive detection of hydrogen peroxide

Abstract

Hydrogen peroxide (H2O2) is an important molecule in biological and environmental systems. In living systems, H2O2 plays essential functions in physical signaling pathways, cell growth, differentiation, and proliferation. Plasmonic nanostructures have attracted significant research attention in the fields of catalysis, imaging, and sensing applications because of their unique properties. Owing to the difference in the reduction potential, silver nanostructures have been proposed for the detection of H2O2. In this work, we demonstrate the Au@Ag nanocubes for the label- and enzyme-free detection of H2O2. Seed-mediated synthesis method was employed to realize the Au@Ag nanocubes with high uniformity. The Au@Ag nanocubes were demonstrated to exhibit the ability to monitor the H2O2 at concentration levels lower than 200 µM with r2 = 0.904 of the calibration curve and the limit of detection (LOD) of 1.11 µM. In the relatively narrow range of the H2O2 at concentration levels lower than 40 µM, the LOD was calculated to be 0.60 µM with r2 = 0.941 of the calibration curve of the H2O2 sensor. This facile fabrication strategy of the Au@Ag nanocubes would provide inspiring insights for the label- and enzyme-free detection of H2O2.