Au-Pd alloy nanoparticles catalyze the colorimetric detection of hydrazine with methylene blue

Abstract

A colorimetric detection of hydrazine using Ausingle bondPd alloy nanoparticles (NPs) as catalyst is described, in which methylene blue (methylthioninium chloride) acts as a redox indicator. The sensing system with Ausingle bondPd NPs shows a rapid response at room temperature, leading to a color change within a few minutes, which is not achievable with Au or Pd NPs. A linear change in absorbance versus hydrazine concentration ranging from 0.1 to 5.0 mM can be obtained with a detection limit of ~4 × 10−4 M. The catalytic activity of the Ausingle bondPd NPs in the reaction can be attributed to the electronic inductive effect by Au on Pd in the alloy NPs.