Manganese coordination polymer nanoparticles with excellent oxidase-like activity for the rapidly and selectively colorimetric detection of glutathione

Novel kinds of manganese coordination polymer nanoparticles (Mn-IMZs CPNs) were fabricated through selfassemble of imidazole with Mn2+ ions in aqueous solution. The prepared Mn-IMZs CPNs, with remarkable stability, exhibit excellent oxidase-like activity that can effectively catalyze the conversion of the dissolved O2 to O2 center dot , turning the colorless 3,3 ',5,5 '-tetramethylbenzidine (TMB) to blue oxidized TMB (ox-TMB). Based on the inhibitory effect of glutathione (GSH) on the TMB oxidation, a rapid and highly sensitive colorimetric method for the detection of GSH was developed, and the linear ranges are 1.25-50 mu M and 50-112.5 mu M. Besides, the discriminative detection of GSH from cysteine was achieved by using the time lag between N-ethylmaleimide on the destruction of thiol compounds. Finally, the developed method was successfully applied in the quantification of GSH in tablets and rabbit plasma with high accuracy and good recovery.