Ag3PO4 semiconductor exhibits extremely high photooxidative ability for O2 evolution from water as well as organic dye decomposition under visible light irradiation. A much higher quantum efficiency than the previously reported values at wavelengths longer than 420 nm was also achieved with it. Up to now, various methods have been proposed to further enhance and optimize the photoelectric and photocatalytic properties of Ag3PO4 via microstructure control or forming composites with other components to improve its stability, bandgap structure and surface area. Although extensive studies have been made for the photocatalytic applications of various Ag3PO4 micro-/nanoparticles and their composites, the application of Ag3PO4 in biological systems, for example used as biocatalyst, has rarely been studied, while the presence of phosphorus in biological systems is well known. Recently, it was found that Fe3O4 nanoparticles have intrinsic enzyme-like activity similar to peroxidases found in nature, though Fe3O4 are usually thought to be biological and chemical inert. After that, several kinds of micro/nanoparticles with smaller size or special structure were prepared for developing enzyme mimics, including the ferromagnetic nanoparticles with peroxidase-like activity, ceria oxide nanoparticles, and V2O5 nanowires, carbon-based nanomaterials and so on. In contrast to natural enzymes, nanoparticles-based enzyme mimics own prominent advantages. First, they have greater resistance to extremes of pH and temperature, while natural enzymes are usually sensitive to the external conditions and also easily lose their activity. Secondly, nanoparticles-based mimic enzymes have higher stability, while natural enzymes can be digested by proteases. Thirdly, with the extensive development of nanoscience and nanotechnology in the past three decades, the preparation and surface modification of various nanoobjects can be easily carried out, while the synthesis and purification of natural enzymes are still time-consuming, expensive, and also Lomitapide Mesylate difficult. Exploitation of 
new functions of known nanomaterials is one of the most attractive aspects in nanoscience. Inspired by the above pioneering research, we investigated the peroxidase-like activity of Ag3PO4 nanocrystals, considering that some Ag-based metal alloy nanoparticles own intrinsic peroxidase-like activity. Ag3PO4 nanoparticles with smaller size were obtained via a simple colloidal route. It was found that the obtained Ag3PO4 nanoparticles show their ability to catalyze peroxidatic reactions in aqueous media. The kinetic parameters were also tested and compared. The reaction catalyzed by these Ag3PO4 nanoparticles followed a Michaelis-Menten kinetic behavior with an excellent catalytic activity, making it a promising mimic of peroxidase. The new application of Ag3PO4 as peroxidase mimic will add new content to this interesting Taltirelin material. For biomolecular enzymes, the catalytic active center is usually the coordination unsaturated metal sites under the capping of protein networks. For nanoparticles, the surface atoms place in similar situation�Ccoordination unsaturation under the capping of surfactant moleculars. Thus, it is possible that they may share some common points in catalytic process, although the catalysis mechanism of inorganic catalysts and enzymes are usually different. At present stage, the Michaelis-Menten model is widely used for the study of nanoparticle-based enzyme mimetics.