FeS nanoparticles embedded in 2D carbon nanosheets as novel nanozymes with peroxidase-like activity for colorimetric and fluorescence assay of H2O2 and antioxidant capacity

Nanozymes with high catalytic performance play a vital role in the construction of advanced biosensors for the signal detection and analysis of complicated biological samples. Herein, FeS nanoparticles (NPs) embedded in 2D carbon nanosheets (denoted as [email protected] ) are demonstrated to serve as excellent nanozymes with high catalytic activity . Notably, the introduction of mesoporous carbon substrate could effectively improve the enzymatic peroxidase-like catalytic ability of embedded FeS nanozymes, especially in the fluorescence catalytic system . Based on the high peroxidase-like activity of proposed [email protected] nanozymes, a facile method was then designed for H 2 O 2 assay with detection limit as low as 0.78 μM and 0.86 μM for the colorimetric and fluorescence method , respectively. The oxidation of the colorimetric and fluorescence substrates could be ascribed to the hydroxyl radical (·OH) produced by catalytic reaction of H 2 O 2 with [email protected] nanozymes. Thus, the [email protected] nanozymes-based H 2 O 2 sensing platform was further constructed to evaluate the antioxidant capacity of glutathione (GSH), cysteine (Cys), and gallic acid (GA). Notably, [email protected] nanozymes can keep the functionality in a broad pH range (2.0 ~ 9.0) for catalytic reaction, delivering a great potential in the fabrication of advanced biosensors.