Detection of label-free H2O2 based on sensitive Au nanorods as sensor

Abstract

A rapid, reproducible, cost-effective approaches for the detection of hydrogen peroxide has been developed based on the change of localized surface plasmon resonance (LSPR) peak of Au nanorods (NRs). Au NRs were prepared by silver ion-assisted seed-mediated method, which are characterized by UV-vis spectroscopy and transmission electron microscopy. The longitudinal plasmon band of Au nanorods is highly sensitive to their aspect ratios so that LSPR peak of Au NRs was shift with change of their aspect ratios. Hydrogen peroxide (H2O2) with high oxidation potential can decompose Au NRs. As a result, Au NRs can be shortened through an oxidation reaction by H2O2. After shortening Au NRs, the LSPR peaks show blue shift. The LSPR peak of Au NRs displays the dependence of spectral shift on concentration of H2O2. It provides a more simple and sensitive method for detecting H2O2.