Amino-functionalized HPU-23@Ru@Tb as light-driven oxidase-like nanozyme for colorimetric recognition of Hg2+ and ratiometric fluorescence sensing of ClO− and PO43−.

A HPU-23@Ru@Tb-NH2 sensor array with light-driven oxidase-mimicking activity and triple-emission fluorescence was developed. It was composed of a Tb3+-functionalized metal organic framework and Ru(bpy)32+ and applied to the simultaneous detection of Hg2+, ClO−, and PO43− via differently responsive channels. HPU-23@Ru@Tb-NH2 had a photoresponsive colorimetric response toward Hg2+ with a LOD as low as 4.18 nM. In addition, the three emissions of the HPU-23@Ru@Tb-NH2 sensor array were influenced by ClO− and PO43− to varying degrees, causing remarkably distinguishable responses for the fluorescence channels to discriminate ClO− and PO43− from each other. The detection limits of ClO− and PO43− 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. [ABSTRACT FROM AUTHOR]