Colorimetric detection of residual hydrogen peroxide in soaked food based on Au@Ag nanorods

Abstract

A simple and selective colorimetric method for H₂O₂ detection in soaked food samples was developed using Au@Ag nanorods (Au@Ag NRs) as the signal conducter. In the presence of H₂O₂, silver atoms on the surface of Au@Ag NRs are oxidized to silver ions, thereby resulting in the red-shift of the longitudinal surface plasmon resonance peak of Au@Ag NRs accompanied by a sharp-contrast multicolor change. The linear range for the detection of H₂O₂ was from 0 to 100 μmol L⁻¹ with a limit of detection of 3.2 μmol L⁻¹. Compared with the commercialized test strip, the proposed colorimetric sensor showed a much higher color resolution by the naked eyes.