Highly selective fluorescence probe with peptide backbone for imaging mercury ions in living cells based on...

Mercury is an anthropogenic toxic heavy metal found in the environment. It is highly desirable to develop a fluorescence probe that can selectively and sensitively detect mercury ions using a turn-on response. This paper reports the successful development of a peptide fluorescence probe, TP-2 (TPE-Trp-Pro-Gln-His-Glu-NH₂), which uses aggregation-induced emission effects and high selectivity to detect Hg²⁺. After fluorescence was activated, Hg²⁺ was efficiently detected using the change in fluorescence intensity. The detection limit for Hg²⁺ in the buffer solution was 41 nM (R² = 0.9952). Owing to its high sensitivity, high cell permeability, and low biotoxicity, the probe could perform live cell imaging under biological conditions. This study demonstrated that TP-2 can detect Hg²⁺ in complex biological environments.