Applications of mild-condition synthesized metal complexes with enzyme-like activity in the colorimetric and fluorescence analysis

The metal complexes, which are prepared through the coordination of metal ions with organic ligands, have various characteristics such as high porosity and specific surface area. In recent years, the metal complexes with enzyme-like activities have been widely used in colorimetric and fluorescence analysis. The synthesis process of metal complexes under mild conditions is particularly significant as it is not only easy to operate but also safe. In this article, the synthesis processes, catalytic mechanisms, activity regulation methods, and recent research progress of metal-complex nanozymes in the past years (2018 to present) have been summarized. Furthermore, the applications of metal-complex nanozymes-based biosensors in colorimetric and fluorescence detection of various analytes, such as antibiotics, metal ions, mycotoxins, pathogens, pesticides, and proteins, have been summarized and discussed. This review is prospective to promote the further applications of metal complexes with enzyme-like activity synthesized under mild conditions.