Preparation of ZIF-90 Manganese Dioxide Nanosheet Composite and Its Application for Glutathione Detection

ZIF-90-MnO2 nanosheet composite was prepared by growing MnO2 nanosheets on ZIF-90 at 55 degrees C with dissolved oxygen. ZIF-90 provided nucleation sites and support for the growth of MnO2 nanosheets and thus improved the dispersion and oxidase activity of MnO2 nanosheets. A colorimetric sensor based on the oxidase-like activity of ZIF-90-MnO2 was constructed to detect glutathione (GSH) colorimetrically. Under the optimized experimental conditions, the detection limit of GSH was 0.30 mu mol/L (3 sigma), the linear range was 1.25-30 mu mol/L, and the whole detection was completed within 15 min. Coexisting substances in the serum samples did not interfere with the detection. The strategy of preparing ZIF-90-MnO2 nanosheet composite under mild conditions was expected to extend the application of MnO2 as an oxidase-like enzyme.