Generation of MnO2 nanozyme in spherical polyelectrolyte brush for colorimetric detection of glutathione

Novel MnO2 nanozymes were prepared as nanosheets in situ using spherical poly[(2-methacryloyloxyethyl) trimethyl ammonium chloride] (PDMC) brushes (SPB) as nanoreactors. The prepared MnO2 nanozymes were immobilized in SPB (SPB-MnO2) showing high stability and excellent oxidase-like property which could oxidize 3,30,5,50-tetramethylbenzidine (TMB) into oxidized TMB (oxTMB), accompanied by the change of absorption at 653 nm. The MnO2 nanosheets could be decomposed by trace amount of glutathione (GSH) under acidic environment as validated by small angle X-ray scattering (SAXS). The SPB-MnO2/TMB system, with a detection limit of 450 nM, should be an ideal candidate for colorimetric detection of GSH. This work opens a new way to prepare highly stable nanozymes for the detection of GSH. (C) 2019 Published by Elsevier B.V.