Design and Synthesis of a New Terbium Complex-Based Luminescent Probe for Time-Resolved Luminescence Sensing of Zinc Ions

摘要

Luminescent probes/chemosensors based on lanthanide complexes have shown great potentials in various bioassays due to their unique long-lived luminescence property for eliminating short-lived autofluorescence with timeresolved detection mode. In this work, we designed and synthesized a new dual-chelating ligand {4′-[N,N-bis(2-picolyl)amino]methylene-2,2′:6′,2′-terpyridine-6,6′-diyl} bis(methylenenitrilo) tetrakis(acetic acid) (BPTTA), and investigated the performance of its Tb~(3+) complex (BPTTATb~(3+)) for the time-resolved luminescence sensing of Zn~(2+) ions in aqueous media. Weakly luminescent BPTTA-Tb~(3+) can rapidly react with Zn~(2+) ions to display remarkable luminescence enhancement with high sensitivity and selectivity, and such luminescence response can be realized repeatedly. Laudably, the dose-dependent luminescence enhancement shows a good linear response to the concentration of Zn~(2+) ions with a detection limit of 4.1 nM. To examine the utility of the new probe for detecting intracellular Zn~(2+) ions, the performance of BPTTA-Tb~(3+) in the time-resolved luminescence imaging of Zn~(2+) ions in living HeLa cells was investigated. The results demonstrated the applicability of BPTTA-Tb~(3+) as a probe for the time-resolved luminescence sensing of intracellular Zn~(2+) ions.