Cao Jianhua, Ding Liping, Hu Wenting, Chen Xiangli, Chen Xiao, Fang Yu
Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University , Xi'an 710062, P. R. China.
Langmuir. 2014 Dec 23;30(50):15364-72. doi: 10.1021/la5039798. Epub 2014 Dec 11.
A new cationic dansyl derivative-based (DIlSD) fluorescence probe was designed and synthesized. Its combination with anionic surfactant SDS assemblies shows enhanced fluorescence intensity and blue-shifted maximum wavelength. Its fluorescence can be slightly quenched by Cu(2+); however, the fluorescence quenching efficiency by Cu(2+) is highly increased upon titration of arginine (Arg). As a result, the ternary system containing the cationic fluorophore, anionic surfactant, and Cu(2+) functions as a highly sensitive and selective sensor to Arg. The optimized sensor system displays a detection limit of 170 nM, representing the highest sensitivity to Arg in total aqueous solution by a fluorescent sensor. Control experiments reveal that the imidazolium groups in the fluorophore, the anionic surfactant, and Cu(2+) all play important roles in the process of sensing Arg. The electrostatic interaction between the cationic fluorophore and anionic surfactants facilitates the binding of imidazolium rings with Cu(2+), the surfactant surface-anchored Cu(2+) is responsible for further binding of Arg, and the electrostatic interaction between anionic surfactants and positively charged amino acids accounts for the selective responses to Arg.
设计并合成了一种基于新型阳离子丹磺酰衍生物（DIlSD）的荧光探针。它与阴离子表面活性剂SDS聚集体结合后，荧光强度增强，最大波长发生蓝移。其荧光可被Cu(2+)轻微猝灭；然而，在加入精氨酸（Arg）进行滴定后，Cu(2+)对荧光的猝灭效率大幅提高。因此，包含阳离子荧光团、阴离子表面活性剂和Cu(2+)的三元体系可作为对Arg高度灵敏且选择性高的传感器。优化后的传感器系统检测限为170 nM，是荧光传感器在全水溶液中对Arg灵敏度最高的。对照实验表明，荧光团中的咪唑鎓基团、阴离子表面活性剂和Cu(2+)在检测Arg的过程中均发挥重要作用。阳离子荧光团与阴离子表面活性剂之间的静电相互作用促进了咪唑鎓环与Cu(2+)的结合，表面活性剂锚定在表面的Cu(2+)负责与Arg进一步结合，而阴离子表面活性剂与带正电荷氨基酸之间的静电相互作用则解释了对Arg的选择性响应。
