Highly selective and sensitive peptide-based fluorescent chemosensor for detection of Zinc(II) ions in aqueous medium and living cells

摘要

A novel peptide-based chemosensor (L, Dansyl-Asp-His-NH2) has been successfully designed and synthesized. L displayed excellent selectivity in fluorescence detection of Zn2+ over other essential metal ions, with a binding constant value of 4.09 x 10(10) M-2. Further, a Job's plot confirmed the 2:1 stoichiometry of the complex formation between the L and Zn2+ ions. L exhibited a highly-sensitive strong fluorescence "turn-on" effect for Zn2+ in aqueous solution, with a detection limit for Zn2+ calculated at 36.8 nM. Notably, L served as a recyclable chemosensor, which was cyclically controlled by Zn2+ and Na(2)EDTA. Moreover, L exhibited low toxicity in HK2 normal cells, and was then applied to monitor intracellular Zn2+ and Na(2)EDTA in human prostate cancer cells (LNCaP cells).