Bispyrene/surfactant assemblies as fluorescent sensor platform: detection and identification of Cu2+ and Co2+ in aqueous solution
作者:Liping Ding、Shihuai Wang、Yuan Liu、Jianhua Cao、Yu Fang
DOI:10.1039/c3ta10453b
日期:——
A cationic bis-pyrene derivative was prepared and its assemblies with anionic surfactant to function as fluorescent sensor platforms for heavy metal ions in aqueous solution were evaluated. Optical spectroscopy measurements illustrated that both UV-vis absorption and fluorescence emission spectra of bis-pyrene could be well enhanced in the assemblies with the anionic surfactant, SDS. Moreover, fluorescence quenching studies revealed that the sensitivity of bis-pyrene/SDS assemblies is highly dependent on the concentration of SDS. The optimized sensor platform exhibited not only a high sensitivity towards both Cu2+ and Co2+ in aqueous solution with detection limits lower than 100 nM but also a high selectivity towards these two metal ions over a series of divalent metal ions including Ba2+, Ca2+, Hg2+, Mg2+, Ni2+, Pb2+, Zn2+, Cd2+, and Fe3+. The high sensitivity was demonstrated to be due to the electrostatic interaction between the metal cations and the anionic surfactants, which dramatically increases the local concentration of metal ions in the near vicinity of pyrene moieties. Moreover, the metal ion target could be identified by addition of glycine to the quenched system, where a dramatic turn-on fluorescence was observed for the Cu2+-quenched system whereas a further turn-off fluorescence was found for the Co2+-quenched system. Furthermore, the recovery of Cu2+-quenched fluorescence could be utilized to provide a turn-on fluorescence sensor for neutral amino acids.
合成了一种阳离子双芘衍生物,并评估其与阴离子表面活性剂的组装,以作为水溶液中重金属离子的荧光传感平台。光学光谱测量表明,双芘的紫外-可见吸收和荧光发射光谱在与阴离子表面活性剂SDS的组装中均得到了良好的增强。此外,荧光猝灭研究揭示,双芘/SDS组装的灵敏度高度依赖于SDS的浓度。经过优化的传感平台不仅对水溶液中的Cu2+和Co2+表现出高灵敏度(检测限低于100 nM),还对这两种金属离子相对于一系列二价金属离子(包括Ba2+、Ca2+、Hg2+、Mg2+、Ni2+、Pb2+、Zn2+、Cd2+和Fe3+)表现出很高的选择性。高灵敏度的原因是金属阳离子与阴离子表面活性剂之间的静电相互作用,这显著提高了金属离子在苯并芘基团附近的局部浓度。此外,通过向猝灭系统中添加甘氨酸,可以识别目标金属离子,其中在Cu2+猝灭的系统中观察到显著的荧光恢复,而在Co2+猝灭的系统中则发现进一步的荧光熄灭。此外,Cu2+猝灭荧光的恢复可用于提供中性氨基酸的开启荧光传感器。