Title
A peptide-based multifunctional fluorescent probe for Cu2+, Hg2+ and biothiol
Author
Xuliang Pang, Lei Gao, Huiyun Feng, Yuehao Li, Lianzhi Li, Jinming Kong
Year
2018
Journal
New Journal of Chemistry
Abstract
A peptide-based fluorescent probe (Dansyl-His-Pro-Gly-Trp-NH2, D-P4) bearing dansyl fluorophore and tryptophan residue has been developed for Hg2+, Cu2+ and biothiol (-SH). DP-4 exhibited high selectivity and sensitivity for Cu2+ and Hg2+ among 17 metal ions and 6 anions. D-P4 could differentiate Hg2+ and Cu2+ by ratiometric response toward Hg2+ and quenching response to Cu2+. Upon the addition of Hg2+ or Cu2+ ion, D-P4 solution displayed visible to the naked eye under a UV lamp. The limits of detection (LOD) of DP-4 are 37 nM for Hg2+ and 105 nM for Cu2+, the latter for Cu2+ was much lower than the drinking water maximum contaminant levels of EPA. Additionally, the binding stoichiometry, binding affinity and pH influence of D-P4 for Hg2+ and Cu2+ ions were also studied. Determination of Hg2+ and Cu2+ in river water samples with D-P4 showed satisfactory results. It is noteworthy that D-P4-Hg system could be regenerated by cysteine (Cys), which was confirmed by circular dichroism (CD) and UV-Vis absorption spectra. Moreover, D-P4-Hg system could be used to detect cysteine, homocysteine (Hcy) and glutathione (GSH). Results indicated that D-P4-Hg system can selectively detect cysteine among 20 common amino acids with LOD of 82 nM.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Chemical stability, Sensor, Biochemistry