Acetylcholine detection at micromolar concentrations with the use of an artificial receptor-based fluorescence switch

作者：Korbakov Nina; Timmerman Peter^*; Lidich Nina; Urbach Benayahu; Sa'ar Amir; Yitzchaik Shlomo

来源：Langmuir, 2008, 24(6): 2580-2587.

DOI：10.1021/la703010z

An inclusion complex between water-soluble p-sulfocalix[n]arene (C(n), n = 4, 6, 8) and the chromophore trans4-[4-(dimethylamino)styryl]-1-methylpyridinium-p-toluenesulfonate (D) formed the basis for a highly sensitive sensor for the selective detection of neurotransmitter acetylcholine (ACh). Formation of the [C(n)center dot D] complex (K(a) = similar to 10(5) M(-1)) was accompanied by a drastic increase (up to 20-60-fold) in the chromophore relative quantum yield and by a large hypsochromic shift of the emission band maximum. The observed optical effects are fully reversible: ACh displaces the chromophore molecules from the calixarene cavity as shown by the reappearance of the free chromophore emission band. Formation and dissociation of the complex were studied by fluorescence, (1)H NMR, and UV-vis absorption spectroscopies. The [C(n)center dot D] complex is capable of sensing ACh selectively in solution at sub-micromolar concentrations. Immobilization of monocarboxyl p-sulfocalix[4]arene (C(4m)) on an oxide-containing silicon surface is in keeping with its properties, such as chromophore binding and the ability of the immobilized inclusion complex to detect ACh. The unique [C(m)center dot D] complex optical, switching paves the way for application in ACh imaging and optoelectronic sensing.

• 出版日期2008-3-18