Department of Chemistry, Bowling Green State University , Bowling Green, Ohio 43403, United States.
J Am Chem Soc. 2014 Aug 13;136(32):11396-401. doi: 10.1021/ja504535q. Epub 2014 Jul 29.
One of the well-known strategies for anion sensing is an indicator (dye) displacement assay. However, the disadvantage of the dye displacement assays is the low sensitivity due to the excess of the dye used. To overcome this setback, we have developed an "Intramolecular Indicator Displacement Assay (IIDA)". The IIDAs comprise a receptor and a spacer with an attached anionic chromophore in a single-molecule assembly. In the resting state, the environment-sensitive anionic chromophore is bound by the receptor, while the anionic substrate competes for binding into the receptor. The photophysical properties of the dye exhibit change in fluorescence when displaced by anions, which results in cross-reactive response. To illustrate the concept, we have prepared IID sensors 1 and 2. Here, the characterization of sensors and microtiter arrays comprising the IIDA are reported. The microtiter array including IID sensors 1 and 2 is capable of recognizing biological phosphates in water. The utility of the IIDA approach is demonstrated on sensing of a phosphonate herbicide glyphosate and other biologically important anions such as pyrophosphate in the presence of interferent sodium chloride.
阴离子传感的一种知名策略是指示剂（染料）置换分析。然而，由于染料用量过多，染料置换分析的缺点是灵敏度低。为了克服这一障碍，我们开发了一种“分子内指示剂置换分析（IIDA）”。IIDAs 由受体和间隔子组成，在单个分子组装中带有附着的阴离子生色团。在静止状态下，环境敏感的阴离子生色团与受体结合，而阴离子底物则竞争与受体结合。当被阴离子置换时，染料的光物理性质会发生荧光变化，从而产生交叉反应性响应。为了说明这一概念，我们制备了 IIDA 传感器 1 和 2。这里报告了包括 IIDA 的传感器和微量滴定板的表征。包含 IIDA 传感器 1 和 2 的微量滴定板能够在水中识别生物磷酸盐。在存在干扰物氯化钠的情况下，IIDA 方法在检测膦酸除草剂草甘膦和其他生物重要阴离子（如焦磷酸盐）方面的应用得到了证明。
