Designing CoS 1.035 Nanoparticles Anchored on N-Doped Carbon Dodecahedron as Dual-Enzyme Mimics for the Colorimetric Detection of H 2 O 2 and Glutathione.

In recent years, the exploration of the nanozyme, an artificial enzyme with the structure and function of natural enzymes, has become a hot topic in this field. Although significant progress has been made, it is still a huge challenge to design nanozymes with multiple enzyme-like catalytic activities. In this work, we have successfully fabricated a colorimetric sensing platform to mimic peroxidase-like and oxidase-like activities by the CoS 1.035 nanoparticles decorated N-doped carbon framework porous dodecahedrons (abbreviated to CoS 1.035 /N-C PDHs). And the catalytic mechanism of CoS 1.035 /N-C PDHs toward the peroxidase-like and oxidase-like activities is systematically explored. The results display that CoS 1.035 /N-C PDHs can catalyze the oxidation of the colorless substrate 3,3,'5,5'-tetramethylbenzidine (TMB) into blue oxidized TMB (ox-TMB) by disintegrating H 2 O 2 or the physically/chemically absorbed O 2 into different ROS species (·OH or O 2 ·- ) in the presence or absence of H 2 O 2 . Therefore, on the basis of the dual-enzyme mimic activities of CoS 1.035 /N-C PDHs, the bifunctional colorimetric sensing platform is established for H 2 O 2 detection with a wide linear range of 0.5-120 μM and glutathione detection with a linear range of 1-60 μM, respectively. This work provides an efficient platform for dual-enzyme mimics, expanding the application prospect of Co-based chalcogenides as enzyme mimics in biosensing, medical diagnosis, and environment monitoring.