Amino-functionalized HPU-23@Ru@Tb as light-driven oxidase-like nanozyme for colorimetric recognition of Hg and ratiometric fluorescence sensing of ClO and PO.

A HPU-23@Ru@Tb-NH sensor array with light-driven oxidase-mimicking activity and triple-emission fluorescence was developed. It was composed of a Tb-functionalized metal organic framework and Ru(bpy) and applied to the simultaneous detection of Hg, ClO, and PO via differently responsive channels. HPU-23@Ru@Tb-NH had a photoresponsive colorimetric response toward Hg with a LOD as low as 4.18 nM. In addition, the three emissions of the HPU-23@Ru@Tb-NH sensor array were influenced by ClO and PO to varying degrees, causing remarkably distinguishable responses for the fluorescence channels to discriminate ClO and PO from each other. The detection limits of ClO and PO were 12.26 µM and 0.197 nM, respectively. Therefore, this work demonstrates the feasibility of multi-emission and multi-mode sensing platform, which is able to combine the advantages of different strategies for solving the problems of various toxic substances coexisting in the environment while meeting the needs of accurate and precise results and no side interferences.