A novel fluorescence "turn off-on" nano-sensor for detecting Cu2+ and Cysteine in living cells

作者:Jiang, Weina; Yang, Shilong; Lu, Wen; Gao, Buhong; Xu, Li*; Sun, Xu; Jiang, Dong; Xu, Hai-Jun; Ma, Mengtao*; Cao, Fuliang
来源:Journal of Photochemistry and Photobiology A: Chemistry , 2018, 362: 14-20.
DOI:10.1016/j.jphotochem.2018.05.004

摘要

In this work, a novel fluorescent sensor (quercetin-Pluronic-F127 nano-micelles) was prepared by the facile self-assembly method with natural quercetin (Qc) and Pluronic-F127 (F127). Qc-F127 nano-micelles were characterized by TEM which indicated that Qc have successfully entered into the amphiphilic micelle. The nano micelles with sizes of 25 to 40 nm showed a strong green fluorescence (FL). The sensor exhibits high sensitivity and selectivity towards Cu2+ with a linear range of 5 x 10(-8)-4 x 10(-8) mol L-1, the detection limit of 1 x 10(-8) mol L-1. Moreover, the Qc-F127 nano-micelles can be used to detect Cu2+ in vitro due to their good biocompatibility. Besides Cu2+ sensing, when Cysteine (Cys) were added, the FL intensity of Qc-F127-Cu(II) system could be restored due to the chelation interactions between Cu2+ ions and the sulfydryl and amino groups of Cys. So, Qc-F127-Cu(II) system can used to detect Cys, and the linear range and the limit of detection of the Qc-F127-Cu2+ system were 3 x 10(-7)-3.5 x 10(-5) mol L-1 and 6 x 10(-8) mol L-1. Moreover, Qc-F127-Cu(II) has been used for imaging of Cys in cells, which demonstrates its values for potential application in biological systems.