A water soluble N-methylpyridinium dye (DABP) was synthesized and investigated as a fluorescence probe for the detection of anionic surfactants. DABP shows strong solvatochromism with emission at 685 nm in water. The probe-surfactant interaction induces distinct color changes and optical properties. In the presence of anionic surfactants such as SDS, AOT and zwitterionic surfactant such as CHAPS, a multi-fold intensity enhancement is observed but not with positively charged surfactant, CTAB indicating the selectivity for negatively charged surfactants. This is ascribed to the electrostatic attraction between the negatively charged surfactant head group and the positively charged pyridinium ring of the diarylbutadiene chromophore. Such distinguishable emission behavior may be of interest for designing fluorogenic sensors for targeted detection.

中文翻译：

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发出红色光的阳离子荧光团作为阴离子表面活性剂的探针

合成了水溶性N-甲基吡啶鎓染料（DABP），并将其用作检测阴离子表面活性剂的荧光探针。DABP表现出很强的溶剂致变色作用，在水中的发射波长为685 nm。探针与表面活性剂的相互作用引起明显的颜色变化和光学性质。在阴离子表面活性剂（例如SDS，AOT和两性离子表面活性剂（例如CHAPS））的存在下，可以观察到强度增强倍数，但带正电荷的表面活性剂CTAB则不能观察到强度增强，这表明带负电荷的表面活性剂具有选择性。这归因于二芳基丁二烯生色团的带负电荷的表面活性剂头基与带正电荷的吡啶鎓环之间的静电吸引。对于设计用于目标检测的荧光传感器，这种可区别的发射行为可能是令人感兴趣的。