Meng Qingtao, Shi Yu, Wang Cuiping, Jia Hongmin, Gao Xue, Zhang Run, Wang Yongfei, Zhang Zhiqiang
School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114044, China.
Org Biomol Chem. 2015 Mar 14;13(10):2918-26. doi: 10.1039/c4ob02178a.
Chemosensors play important roles in cation and anion recognition in biological, industrial, and environmental processes. Although many efforts have been made to develop artificial fluorescent receptors for Cu(2+) and S(2-), their applications in the detection in bulk solutions are limited. In this work, we report a novel fluorescence chemosensor (NL) based on the 7-nitrobenz-2-oxa-1,3-diazole (NBD) fluorophore for the quantification of Cu(2+) and S(2-) in single intact cells. NL specifically binds to Cu(2+) in the presence of other competing cations, and evident changes in UV-vis and fluorescence spectra in HEPES buffer are noticed. Based on the displacement approach, the selective sense S(2-) with the in situ generated NL-Cu(2+) ensemble gives a remarkable recovery of fluorescence and UV-vis absorption spectra. The detection limits of NL for Cu(2+) and NL-Cu(2+) for S(2-) were estimated to be 1.6 nM and 0.17 μM, respectively. NL and the resultant complex NL-Cu(2+) exhibit low cytotoxicity and cell-membrane permeability, which makes them capable of Cu(2+) and S(2-) imaging and quantification in living MDA-MB-231 cells.
化学传感器在生物、工业和环境过程中的阳离子和阴离子识别方面发挥着重要作用。尽管人们已经做出了许多努力来开发用于铜离子（Cu(2+)）和硫离子（S(2-)）的人工荧光受体，但它们在本体溶液检测中的应用仍然有限。在这项工作中，我们报道了一种基于7-硝基苯并-2-恶唑-1,3-二唑（NBD）荧光团的新型荧光化学传感器（NL），用于定量单个完整细胞中的Cu(2+)和S(2-)。在存在其他竞争性阳离子的情况下，NL能特异性结合Cu(2+)，并且在HEPES缓冲液中紫外可见光谱和荧光光谱会出现明显变化。基于置换法，原位生成的NL-Cu(2+)组合能选择性地识别S(2-)，使荧光和紫外可见吸收光谱有显著恢复。NL对Cu(2+)的检测限和NL-Cu(2+)对S(2-)的检测限分别估计为1.6 nM和0.17 μM。NL以及生成的复合物NL-Cu(2+)表现出低细胞毒性和细胞膜通透性，这使得它们能够对活的MDA-MB-231细胞中的Cu(2+)和S(2-)进行成像和定量分析。
