A Highly Stable 3D Luminescent Indium–Polycarboxylic Framework for the Turn-off Detection of UO₂²⁺, Ru³⁺, and Biomolecule Thiamines

Hydrothermal reaction of the multidentate organic ligand (H 6 TTHA) with indium chloride (InCl 3 ) produced a highly stable 3D luminescent indium-organic framework [In 2 (OH) 2 (H 2 TTHA)(H 2 O) 2 ] n ( 1 ). Complex 1 exhibits remarkable luminescent properties, especially the multifunction sensitivity and selectivity for detecting Ru 3+, UO 2 2+; as well as small biomolecules thiamines (TPP, TMP, and TCl) based on a “turn-off” manner. In particular, the pyrophosphate groups of TPP and the phosphate groups of TMP could further affect the quenching rate, leading to different luminescent responds. In addition, we also discussed and proved the luminescence quenching mechanism in detail through comparative test and PXRD characterization. Therefore, complex 1 could be used as a kind of excellent luminescence sensor to detect Ru 3+, UO 2 2+, and thiamines (TPP, TMP, and TCl).