基于BODIPY的生物硫醇荧光探针的合成和光物理性质

Synthesis and photophysical properties of biothiols fluorescent probe based on BODIPY

以4,4-二氟-8-(4-羟基苯基)-1,3,5,7-四甲基-4-硼-3a,4a-二氮杂-s-茚烯(BODIPY)和N-丁基咔唑-3-甲醛(Ⅱ)为原料合成了一种具有红光发射的荧光分子Ⅲ,其在二氯甲烷中的最大荧光发射波长为617 nm。荧光分子Ⅲ与作为生物硫醇识别基团的4-氯-7-硝基-1,2,3-苯并氧杂二唑(NBD-Cl)反应得到了一种可用于生物硫醇检测的探针BDP-NBD。由于光诱导电子转移(PET)的荧光猝灭作用,BDP-NBD发射较弱荧光,但在生物硫醇存在的情况下,PET过程受到阻止,其荧光发射强度显著增强约95倍。这种"Turn on"型荧光探针能有效检测生物硫醇,并展现出较低的检出限〔同型半胱氨酸(Hcy)6.51×10–8 mol/L;谷胱甘肽(Gsh)4.25×10–8 mol/L;半胱氨酸(Cys)4.28×10–8 mol/L〕。此外,在多种金属离子及氨基酸存在下,该探针分子仍能高效识别生物硫醇。

A red emitting fluorescent moleculeⅢwas synthesized from 4,4-difluoro-8-(4-hydroxyphenyl)-1,3,5,7-tetramethyl-4-bora-3 a,4 a-diaza-s-indacene(BODIPY)and 9-butyl-9 H-3-carboxaldehyde(compoundⅡ).Its maximum fluorescence emission wavelength was 617 nm in dichloromethane.Then,a novel probe BDP-NBD for biothiol detection was obtained by the reaction of fluorescent moleculeⅢwith 4-chloro-7-nitro-1,2,3-benzoxadiazole(NBD-Cl)as recognition group of biothiols.Probe BDP-NBD showed very weak emission due to the fluorescence quenching effect of photoinduced electron transfer(PET).However,in the presence of biothiols,PET process was blocked,and its fluorescence emission intensity was increased about 95 times.This kind of"Turn on"fluorescent probe could effectively detect biothiols and exhibit low detection limits[6.51×10–8 mol/L for homocysteine(Hcy),4.25×10–8 mol/L for glutataione(Gsh),4.28×10–8 mol/L for cysteine(Cys)].Furthermore,in the presence of a variety of metal ions and amino acid(L-aspartic acid),the probe was still able to efficiently recognize biothiols.