A novel peptide-based fluorescent probe for sensitive detection of zinc (II) and its applicability in live cell imaging.

In this work, we report SPSS synthesis of a new peptide-based fluorescent probe (L) capable of detecting Zn2+ with little interference in 100% aqueous solutions at physiological pH. Furthermore, L showed excellent sensitivity, with a detection limit of 26.77 nM. The 2:1 binding ratio between L and Zn2+ was determined using fluorometric titration, Job's plot and ESI-MS analyses. The "off-on-off" type fluorescence change of L was demonstrated by alternately adding Zn2+ and EDTA based on a formation-separation process of the complex, indicating that L could serve as a reversible probe. Moreover, MTT studies demonstrated that L has low biotoxicity, and could be successfully used for detection of Zn2+ and EDTA in live cells.