Urchin-like trimanganese tetraoxide particles with oxidase-like activity for glutathione detection

Abstract

Urchin-like trimanganese tetroxide (Mn3O4) particles were synthesized through a simple and gentle method, and characterized by XRD, XPS, FTIR, SEM, TEM, and UV–vis absorption. The intrinsic enzyme-like activity of urchin-like Mn3O4 particles was evaluated by 3, 3′, 5, 5′-tetramethylbenzidine (TMB) in the absence of H2O2. The optimization of experiment conditions of urchin-like Mn3O4 particles on the oxidase-like activity was further investigated. It was exhibited that urchin-like Mn3O4 particles were best-performing with a highly oxidase-like catalytic activity in the model reaction. Due to the selective inhibition of glutathione (GSH) on the high oxidase-like activity of urchin-like Mn3O4 particles, a selective and sensitive colorimetric assay for GSH had been established. The method exhibited linear relationship over the GSH concentration range from 0.1 μM to 30 μM, with a low detection limit of 20.0 nM and a rapid response of less than 3 min. Based on high specificity of GSH inhibition, urchin-like Mn3O4 particles could be used to detect GSH concentration in human serum samples.