Pawar Shweta, Akula Mahesh, Labala Suman, Venuganti Venkata Vamsi Krishna, Bhattacharya Anupam, Nag Amit
Department of Chemistry, BITS Pilani Hyderabad Campus, Hyderabad, 500078, India.
Department of Pharmacy, BITS Pilani Hyderabad Campus, Hyderabad, 500078, India.
Chempluschem. 2016 Dec;81(12):1339-1348. doi: 10.1002/cplu.201600382. Epub 2016 Oct 13.
The bipyridine-based constructs 4-(pyridine-2-yl)-3H-pyrrolo[2,3-c]quinoline (PPQ) and [6-(3H-pyrrolo[2,3-c]quinolin-4-yl)pyridin-2-yl]methanol (PPQ-OH) and their assemblies with surfactants are evaluated as turn-on fluorescent sensors for Zn ions in aqueous solution. This study strives to overcome the problem of low water solubility of the hydrophobic PPQ and PPQ-OH by using micelles. Whereas the ligands show selective sensing behavior for Zn over important biological cations including Na , K , Ca , Mg in anionic sodium dodecyl sulfate and non-ionic Tween 80 micelles, no Zn sensing is observed in cationic cetyltrimethylammonium bromide micelles. Unlike in DMF, Cd interference is observed in aqueous conditions, which can be avoided either by performing the study at pH≥9 or by carrying out a time-resolved fluorescence study. Analysis of the Job plot data, the fluorescence lifetimes, and experiments on varying micellar shape and pH, confirms that the coordination volume of the resulting octahedral metal complex and formation of a five-membered chelate ring are critical factors for Cd interference. The described sensing systems are capable of detecting Zn ions at the micromolar level. Additionally, it is shown that PPQ and PPQ-OH can be used to detect Zn in HeLa cells under physiological conditions in bioimaging studies.
对基于联吡啶的化合物4-(吡啶-2-基)-3H-吡咯并[2,3-c]喹啉(PPQ)和[6-(3H-吡咯并[2,3-c]喹啉-4-基)吡啶-2-基]甲醇(PPQ-OH)及其与表面活性剂的组装体作为水溶液中锌离子的开启型荧光传感器进行了评估。本研究致力于通过使用胶束来克服疏水性PPQ和PPQ-OH水溶性低的问题。虽然在阴离子十二烷基硫酸钠和非离子吐温80胶束中，这些配体对锌表现出比对包括Na⁺、K⁺、Ca²⁺、Mg²⁺在内的重要生物阳离子的选择性传感行为，但在阳离子十六烷基三甲基溴化铵胶束中未观察到锌传感。与在N,N-二甲基甲酰胺中不同，在水性条件下观察到镉的干扰，这可以通过在pH≥9时进行研究或通过进行时间分辨荧光研究来避免。对Job曲线数据、荧光寿命的分析以及对不同胶束形状和pH的实验证实，所得八面体金属配合物的配位体积和五元螯合环的形成是镉干扰的关键因素。所描述的传感系统能够检测微摩尔水平的锌离子。此外，结果表明，在生物成像研究的生理条件下PPQ和PPQ-OH可用于检测HeLa细胞中的锌。
