Au@Ag nanostructures for the sensitive detection of hydrogen peroxide.

Hydrogen peroxide (HO) is an important molecule in biological and environmental systems. In living systems, HO 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 HO. In this work, we demonstrate the Au@Ag nanocubes for the label- and enzyme-free detection of HO. 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 HO at concentration levels lower than 200 µM with r = 0.904 of the calibration curve and the limit of detection (LOD) of 1.11 µM. In the relatively narrow range of the HO at concentration levels lower than 40 µM, the LOD was calculated to be 0.60 µM with r = 0.941 of the calibration curve of the HO sensor. This facile fabrication strategy of the Au@Ag nanocubes would provide inspiring insights for the label- and enzyme-free detection of HO