Research Center for Solar Energy Chemistry and Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan.
ACS Appl Mater Interfaces. 2011 Dec;3(12):4649-56. doi: 10.1021/am201069n. Epub 2011 Nov 11.
A simple copolymer consisting of N-isopropylacrylamide and coumarin-conjugated spiropyran (CS) units, poly(NIPAM-co-CS), has been synthesized. This polymer enables selective fluorometric detection of cyanide anion (CN(-)) in water at room temperature. The polymer itself shows almost no fluorescence, but shows a strong blue fluorescence in the presence of CN(-) under irradiation of UV light. The fluorescence enhancement occurs via a nucleophilic interaction between CN(-) and the photoformed merocyanine form of the CS unit, leading to a localization of π-electrons on the coumarin moiety. The polymer enables accurate determination of very low levels of CN(-) (>0.5 μM). The polymer can be recovered from water by simple centrifugation at high temperature (>40 °C), due to the heat-induced aggregation of the polymer. In addition, the polymer is regenerated by simple acid treatment, and the resulting polymer is successfully reused for further CN(-) sensing without loss of sensitivity.
一种由 N-异丙基丙烯酰胺和香豆素偶联螺吡喃（CS）单元组成的简单共聚物，聚（NIPAM-co-CS），已经被合成。该聚合物能够在室温下选择性地在水中荧光检测氰根阴离子（CN(-)）。聚合物本身几乎没有荧光，但在存在 CN(-)的情况下，在紫外光照射下显示出很强的蓝色荧光。荧光增强是通过 CN(-)与 CS 单元的光致变色的内酰胺形式之间的亲核相互作用发生的，导致电子在香豆素部分的局部化。该聚合物能够准确地检测非常低浓度的 CN(-)(>0.5 μM)。由于聚合物的热诱导聚集，聚合物可以通过在高温（>40°C）下简单离心回收。此外，聚合物可以通过简单的酸处理再生，所得聚合物可以成功地重复用于进一步的 CN(-)传感，而不会降低灵敏度。
