基于萘酰亚胺的生物硫醇探针的合成及对含硫醇氨基酸的检测

合成了以4-羟基萘酰亚胺为荧光团,2,4-二硝基苯磺酰氧基为特异性识别基团的生物硫醇探针4-(2,4-二硝基苯磺酰氧基)-正丁基-1,8-萘酰亚胺(DNSBN).吸收光谱和荧光光谱结果表明, DNSBN对半胱氨酸(Cys)、同型半胱氨酸(Hcy)和谷胱甘肽(GSH)3种生物硫醇分子具有高效的检测识别能力,不受其它17种天然氨基酸的干扰.同时,通过荧光滴定实验证实了此探针是一种比率型探针,555 nm处的荧光强度与溶液中的生物硫醇分子浓度在0 ~ 20 μmol/L范围内呈良好的线性关系,对Cys、Hcy和GSH的检出限(3σ)分别为25.9、92.0和77.9 nmol/L.而吸收光谱、荧光光谱和质谱表征数据显示,生物硫醇与2,4-二硝基苯磺酸酯发生亲核取代反应并导致磺酸酯的分解.随着识别基团的解离,探针分子的d-PeT (donor-excited photoinduced electron transfer) 效应被解除,并出现非常明显的比色与荧光变化.HeLa细胞成像实验表明,探针DNSBN具有良好的生物相容性,能够对细胞外源性生物硫醇分子进行检测.

Synthesis of Naphthalimide-based Biothiols Probe and Detection of Amino Acids Containing Sulfhydryl Groups

A novel probe (DNSBN) towards biothiols on the basis of 4-hydroxynaphthalimide as fluorophores and 2, 4-dinitrobenzenesulfonyloxy group as specific recognition site was designed and synthesized.The result of absorption and fluorescence spectral analyses indicated that the probe had high sensitivity and selectivity towards cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), and the detection was not affected by other 17 kinds of natural amino acids.Meanwhile, it was confirmed that DNSBN was a ratiometric probe through the fluorescence titration experiment, and the fluorescent intensity at 555 nm had a high linear relationship with biothiols concentration in the range of 0-20 μmol/L.The detection limits (3σ) of Cys, Hcy and GSH were 25.9, 92.0 and 77.9 nmol/L, respectively.The absorption, emission and mass spectra indicated that biothiols could be engaged in nucleophilic substitution reaction with 2,4-dinitrobenzenesulfonate, which induced the sulfonic esters decomposed.With the departure of receptor unit, the d-PeT progress (donor-excited photoinduced electron transfer) was blocked with an obvious colorimetric and fluorescence change.Finally, HeLa cell imaging experiments verified that DNSBN had good biocompatibility and could be used to detect exogenous biothiols.