Highly selective and sensitive fluorescent probe possessing AIEE and ICT properties for rapid detection of Pb2+ in aqueous medium and its applications in living cells

In this paper, a novel rapid, highly selective and sensitive Pb²⁺ fluorescent probe (E)-N'-((2-(4'-(diphenylamino)-[1,1'-biphenyl]-4-yl)-2H-1,2,3-triazol-4-yl)methylene) (DBTBH) was synthesized. The probe DBTBH not only exhibited more excellent selectivity and sensitivity to Pb²⁺ detection compared with other analytes (include metal ions and anions) in H₂ O:THF solution (v:v = 9:1, 10 mM Tris-HCl, 1 mM KI, pH 7.4), but also had excellent optical properties such as aggregation-induced emission enhancement (AIEE) and intramolecular charge transfer (ICT). Detection limit of the probe DBTBH towards Pb²⁺ was 4.49 × 10^-8 M. The possible mechanism was verified by ¹ H NMR titration and HR-MS. Furthermore, the successful detection of Pb²⁺ by DBTBH in real water samples and HeLa cells indicated that DBTBH has great potential for selective recognition of Pb²⁺ in the natural environment and biological systems. These findings will provide a promising new idea for designing better Pb²⁺ fluorescent probes in the future.