A novel peptide-based fluorescent chemosensor (DGC) based on dansyl-appended dipeptide (Gly-Cys-NH2) was synthesized using SPPS technology. DGC exhibited highly sensitive detection of Cadmium (II) ions in 100% aqueous solutions through fluorescent "turn on" response and the detection limits of 14.5 nM. On the other hand, the fluorescence of DGC was almost completely quenched with fast response time when the addition of Cu2+ ions to DGC solutions, the detection limits for Cu2+ was 26.3 nM. In addition, the 2:1 binding stoichiometry of DGC with Cd2+ and Cu2+ were confirmed by Job's plot, fluorescent titration and HR-MS data. More importantly, MTT assays and fluorescence imaging experiments suggested that DGC has outstanding membrane permeability and hypotoxicity, and could be an efficient fluorescent chemosensor for Cd2+ and Cu2+ detection by two different response modes in living LNcap cells.
Keywords: Cd(2+) ions; Cells imaging; Cu(2+) ions; Fluorescent chemosensor; Peptide.
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