Barve Aabha, Lowry Mark, Escobedo Jorge O, Thainashmuthu Josephrajan, Strongin Robert M
Department of Chemistry, Portland State University, 1719 SW 10th Ave, Portland, OR, 97201, USA.
J Fluoresc. 2016 Mar;26(2):731-7. doi: 10.1007/s10895-015-1762-3. Epub 2016 Jan 16.
Elevated homocysteine levels are a well-known independent risk factor for cardiovascular disease. To date, relatively few selective fluorescent probes for homocysteine detection have been reported. The lack of sensing reagents and remaining challenges largely derive from issues of sensitivity and/or selectivity. For example, homocysteine is a structural homologue of the more abundant (ca, 20-25 fold) aminothiol cysteine, differing only by an additional methylene group side chain. Fluorescein tri-aldehyde, described herein, has been designed and synthesized as a sensitive and selective fluorophore for the detection of homocysteine in human plasma samples. It responds to analytes selectively via a photoinduced electron transfer (PET) inhibition process that is modulated by predictable analyte-dye product hybridization and ionization states. Mulliken population analysis of fluorescein tri-aldehyde and its reaction products reveals that the characteristic formation of multiple cationic of homocysteine-derived heterocycles leads to enhanced relative negative charge build up on the proximal phenolate oxygen of the fluorophore as a contributing factor to selective emission enhancement.
同型半胱氨酸水平升高是心血管疾病一个众所周知的独立风险因素。迄今为止，报道的用于检测同型半胱氨酸的选择性荧光探针相对较少。传感试剂的缺乏以及尚存的挑战很大程度上源于灵敏度和/或选择性问题。例如，同型半胱氨酸是含量更为丰富（约20 - 25倍）的氨基硫醇半胱氨酸的结构类似物，两者仅相差一个额外的亚甲基侧链。本文所述的荧光素三醛已被设计并合成，作为一种灵敏且具有选择性的荧光团，用于检测人血浆样本中的同型半胱氨酸。它通过光诱导电子转移（PET）抑制过程对分析物进行选择性响应，该过程由可预测的分析物 - 染料产物杂交和电离状态调节。对荧光素三醛及其反应产物的穆利肯布居分析表明，同型半胱氨酸衍生的杂环多个阳离子的特征形成导致荧光团近端酚氧上相对负电荷积累增强，这是选择性发射增强的一个促成因素。
