Preparation of M–MnCo2O4 (M = Fe, Al, Bi, Cr) nanoenzymes with different doping ratios and detection of glutathione in serum

Abstract

Monitoring the level of glutathione (GSH) in the blood was of great importance in the diagnosis of diseases and human health. Herein, a series of nanomaterials, M–MnCo₂O₄ (M = Fe, Al, Bi, Cr), were prepared by oxalate co-precipitation and calcination, which were endowed with oxidase activity. The 5% doping ratio of Fe–MnCo₂O₄ materials had the best oxidase activity. The materials could oxidize TMB to form ox-TMB while the color of the solution changed from colorless to blue in the absence of H₂O₂. The oxidase activity of the material was inhibited by the addition of GSH, which was able to reduce the blue ox-TMB to colorless TMB. Based on the above experimental phenomenon, a colorimetric sensing platform for the detection of GSH was constructed, which exhibited an excellent linear relationship of 0–30 μM and a low detection limit of 0.1430 μM. These primary results indicated that the MnCo₂O₄ (M = Fe, Al, Bi, Cr) nanomaterials have great potential for application in detection of the level of GSH in human serum with the advantages of being quick and sensitive.