Microchimica Acta | 2019
Ultrathin films of a metal-organic framework prepared from 2-methylimidazole, manganese(II) and cobalt(II) with strong oxidase-mimicking activity for colorimetric determination of glutathione and glutathione reductase activity
Abstract
AbstractNanosheets (NSs; type ZIF-67) of a metal organic framework (MOF) that was prepared from 2-methylimidazole, manganese(II) and cobalt(II) were obtained by an ultrasonic hydrothermal method. Their Mn(II) doping reached as much as 11.3%. The NSs inherit high porosity, a large specific surface, and a large number of active sites. They display superior oxidase-mimicking activity and can catalyze the oxidation of tetramethylbenzidine (TMB) by molecular oxygen to form blue oxTMB. Glutathione (GSH) can reduce oxTMB, so that less blue oxTMB will be present. A simple and rapid method was established for the colorimetric determination of GSH and of the activity of GSH reductase (GR), best at a wavelength of 652\xa0nm. The response to GSH drops linearly in the 0.1–25\xa0μM concentration range. The activity of GR can be quantified in the 0.1 –\xa03\xa0mU⋅mL-1 activity range. The respective detection limits are 0.07\xa0μM and 0.18\xa0mU⋅mL-1.\n Graphical abstractSchematic presentation of colorimetric detection of glutathione and glutathione reductase activity by the\xa0oxidase-mimicking activity of Mn-Co nanosheets in a metal organic framework.