S-doping regulated cerium active sites in CeN nanozyme for enhanced peroxidase-like activity toward GSH detection and antibacterial applications.

Abnormal expression of glutathione (GSH) disrupts the redox equilibrium in organisms, while conventional detection methods are often cumbersome and time-consuming. Herein, a Ce-based graphene-like carbon material (S@Ce-N-C) with excellent POD-like activity was developed using an S-doping pyrolysis strategy. S@Ce-N-C can oxidize colorless TMB to blue oxTMB, while changes in GSH concentration can inhibit its degree of oxidation, resulting in distinct colorimetric response variations. Accordingly, a four-channel colorimetric sensor array for GSH detection was developed, displaying a linear range of 5-100 μM and a detection limit of 0.49 μM. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) demonstrated that the four-channel colorimetric sensor array exhibited excellent discrimination between tumor cells and normal cells, overcoming the limitations of the single-channel colorimetric sensor array. Moreover, given that the POD-like activity of S@Ce-N-C could catalyze H2O2 to generate toxic hydroxyl radicals (•OH), S@Ce-N-C also exhibited unique antibacterial properties.