一种新型的α-氨基酸荧光传感器及其在酶活性检测中的应用

A Novel Fluorescent Chemosensor forα-Amino Acids and Its Application for the Detection of Protease

利用香豆素衍生物与铜离子形成配合物C1-Cu(Ⅱ),其可通过置换法检测α-氨基酸。在配合物C1-Cu(Ⅱ)的溶液中加入α-氨基酸后,表现出明显的荧光增强响应。其中,配合物C1-Cu(Ⅱ)对组氨酸的响应最灵敏,加入过量的组氨酸之后,体系在490nm处的荧光强度增强了约135倍,而且荧光强度的变化与组氨酸浓度在一定范围内呈现较好的线性关系,通过计算可知,该配合物可实现对组氨酸的定量检测。由于胰蛋白酶可催化牛血清白蛋白水解生成α-氨基酸,因此,以牛血清白蛋白为酶基底,配合物C1-Cu(Ⅱ)亦可作为胰蛋白酶的荧光传感器,从而实现无需标记即可对胰蛋白酶进行特异性检测。

Complex C1-Cu（Ⅱ）could act as a new displacement-based fluorescent probe forα-amino acids detection.Upon the addition ofα-amino acids,it displayed marked changes from non-fluorescence to strongly green fluorescence which could be observed by naked-eyes under a normal UV lamp.Especially,histidine exhibited the highest sensitivity：the fluorescent intensity increased to^135-fold of the original one with the addition of excess histidine.Moreover,the intensity change at 490 nm was almost linear with the concentrations of histidine.Furthermore,as the hydrolysis of bovine serum albumin（BSA）with the aid of trypsin producesα-amino acids,the complex of C1-Cu（Ⅱ）with BSA could serve as a label-free,selective,fluorescent sensor toward trypsin with＂turn-on＂fluorescent methods.