Instituto de Investigaciones en Físico Química de Córdoba (INFIQC), Departamento de Química Orgánica, Universidad Nacional de Córdoba, Ciudad Universitaria, Haya de la Torre y Medina Allende, 5000 Córdoba, Argentina.
Talanta. 2011 Jan 15;83(3):1006-13. doi: 10.1016/j.talanta.2010.11.013. Epub 2010 Nov 11.
Alternative and sensitive spectrofluorimetric methods for the determination of hydroxyindoles, such as serotonin (5HT) and 5-hydroxyindoleacetic acid (5HIA), were developed on the basis of supramolecular interaction with cyclodextrin (CD) nanocavities (βCD and hydroxypropyl-βCD, HPCD) at different pH values. Both substrates and receptors have acidic protons, therefore the interactions produced in different systems were considered. The effects of neutral CD at pH 2.00 and 6.994, and of anionic CD at pH 13.00 on the specific acid-base species of the compounds at each pH were determined. In all the conditions studied, the fluorescence of the substrates in the presence of CD increased. The association constants (K(A), mol(-1)L) between the substrates and CD were determined (30-300) and interpreted. A zero-crossing first-derivative spectrofluorimetric method with and without HPCD was developed for the simultaneous determination of 5HT and 5HIA. The limits of detection (L(D), ng mL(-1)) for the best conditions were 0.37 for 5HT and 0.50 for 5HIA at pH 2.00 with HPCD. These L(D) proved to be better than others reported. The applicability of the direct and derivative spectrofluorimetric methods to urine samples was demonstrated with good recoveries 92-110% and R.S.D. 1-10%.
基于环糊精（CD）纳米腔（β-CD 和羟丙基-β-CD，HPCD）与不同 pH 值下的羟基吲哚（如 5-羟色胺（5-HT）和 5-羟吲哚乙酸（5-HIAA））的超分子相互作用，开发了用于测定羟基吲哚的替代和灵敏的荧光光谱法。由于底物和受体都具有酸性质子，因此考虑了在不同体系中产生的相互作用。在 pH 2.00 和 6.994 时测定了中性 CD 以及在 pH 13.00 时阴离子 CD 对每种 pH 下化合物的特定酸碱物种的影响。在研究的所有条件下，CD 存在时底物的荧光均增强。确定了（30-300）并解释了底物与 CD 之间的结合常数（K（A），mol（-1）L）。开发了具有和不具有 HPCD 的零交叉一阶导数荧光光谱法，用于同时测定 5-HT 和 5-HIAA。在 pH 2.00 下用 HPCD 时，最佳条件下 5-HT 和 5-HIAA 的检测限（L（D），ng mL（-1））分别为 0.37 和 0.50。这些 L（D）被证明优于其他报道的方法。直接和导数荧光光谱法在尿液样品中的适用性通过良好的回收率（92-110%）和 R.S.D.（1-10%）得到证明。
