化学学报 ›› 2009, Vol. 67 ›› Issue (5): 381-386. 上一篇    下一篇

研究论文

尼罗红在离子表面活性剂水溶液中的荧光特性

林翠英 赵剑曦* 宋 利

  

  1. (福州大学化学化工学院 应用化学系 福州 350002)

  • 投稿日期:2008-03-28 修回日期:2008-09-25 发布日期:2009-03-14
  • 通讯作者: 赵剑曦

Fluorescence Properties of Nile Red in Ionic Surfactant Aqueous Micellar Solutions

Lin, Cuiying Zhao, Jianxi* Song, Li   

  1. (Department of Applied Chemistry, College of Chemistry and Chemical Engineering,
    Fuzhou University, Fuzhou 350002, China)
  • Received:2008-03-28 Revised:2008-09-25 Published:2009-03-14
  • Contact: Zhao, Jianxi

尼罗红(NR)分子具有大的芳香环和基态时可与水分子形成氢键的吸电子基, 它对增溶在表面活性剂胶束栅栏层的环境尤其敏感, 在十二烷基三甲基溴化铵(C12TABr)胶束水溶液中表现为双重荧光, 最大发射波长分别位于578和630 nm. 十二烷基硫酸钠(SDS)胶束的反离子解离度大于C12TABr胶束, 这不仅增大了NR周边环境的极性, 也增多了溶剂化水, 导致与NR氢键作用增强, 荧光强度低于C12TABr, 但有效促进了分子内扭转电荷转移(TICT)激发态形成, 其布居甚至可达到98%以上, 表观上仅出现了在634 nm的单重荧光峰. NR对环境的敏感特性很好地反映了Gemini表面活性剂初始形成胶束的残缺结构信息, 是检测这类具有强烈相互作用两亲分子聚集行为的良好探针.

关键词: TICT探针, 尼罗红, 环境敏感, 胶束栅栏层信息

The molecule of nile red (NR) contains a big aromatic ring and a carbonyl oxygen (electron acceptor) that can hydrogen-bond with a water molecule, resulting in high sensitivity to the microenvironments of the micellar palisade layer in which NR is solubilized. In the aqueous micellar solution of dodecyltrimethylammonium bromide (C12TABr), the dual fluorescence of NR appeared and the maximum emission wave lengths were at 578 and 630 nm, respectively. The dissociation degree of the counterion from sodium dodecyl sulfate (SDS) micelle was found to be larger than that of C12TABr. This increased both the microenvironment polarity around NR and the hydrated water for the heads resulting in the enhancement of the hydrogen bonds with water. As a result, the fluorescent intensity of SDS solution was reduced compared with that of C12TABr but the TICT state was effectively promoted to form, which produced the high population of the TICT state over 98% and thus apparent single fluorescent peak at 634 nm. By the high sensitivity of NR to microenvironment, the information about uncompleted structure of the micelles formed initially was also obtained, which indicates that NR can be used as the probe to determine the aggregates formed by the amphiphilies with strong intermolecular synergism.

Key words: TICT probe, nile red, environment-sensitivity, the information about the micellar palisade layer