title: Thermoresponsive copolymer containing a coumarin-spiropyran conjugate: reusable fluorescent sensor for cyanide anion detection in water.
abstract: 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.
authors: Research Center for Solar Energy Chemistry and Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan. shiraish@cheng.es.osaka-u.ac.jp
authors: Yasuhiro
authors: Y
authors: Shiraishi
authors: Shigehiro
authors: S
authors: Sumiya
authors: Kenji
authors: K
authors: Manabe
authors: Takayuki
authors: T
authors: Hirai
mesh_terms: D000838:Anions / Q000032:analysis; D001578:Benzopyrans / Q000737:chemistry*; D015374:Biosensing Techniques; D003374:Coumarins / Q000737:chemistry*; D003486:Cyanides / Q000032:analysis*; D005453:Fluorescence; D007211:Indoles / Q000737:chemistry*; D009574:Nitro Compounds / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000838:Anions; D001578:Benzopyrans; D003374:Coumarins; D003486:Cyanides; D007211:Indoles; D009574:Nitro Compounds; D011108:Polymers; D014874:Water Pollutants, Chemical; C088184:spiropyran; C030123:coumarin