一种基于BODIPY的Zn^(2+)荧光探针:ICT增强效应

A BODIPY-Derived Zn^(2+) Fluorescent Sensor: the Enhanced ICT Effect

为克服BODIPY类探针Stokes位移小、发射偏短等不足,本文通过在BODIPY引入α-(4-羟基)苯乙烯基增强分子内电荷转移(ICT)效应并结合meso-位Zn2+螯合团的引入构建了一个发射红移到黄色的、有较大Stokes位移(~50 nm)的BODIPY类Zn2+荧光探针。这些特点有利于降低造影中自发荧光、光毒性和激发的干扰。光谱研究显示探针具有良好的Zn2+特异性荧光增强响应,且其他金属和近中性环境pH的干扰较小。该探针对Zn2+的线性响应范围为0.12~1.2μmol·L-1,检测限为0.18μmol·L-1。HeLa细胞内Zn2+共聚焦荧光成像研究表明该探针具有良好的细胞膜透过能力,可对胞浆内"自由"Zn2+实现可逆跟踪。

Modifying BODIPY with a （4-hydroxyl）styryl group and a Zn2＋ chelator respectively at α- and meso- positions resulted in a Zn2＋ fluorescent sensor of yellow emission（580 nm） and large Stokes shift （-50 nm）. The α- （4-hydroxyl）styryl-enhanced ICT effect is responsible for the enlarged Stokes shift and bathoehromic shifted excitation/emission of BODIPY, which favor to reduce the imaging interference of autofluorescence, phototoxicity and excitation. Photospectroscopic study disclosed the specific Zn2＋-amplified fluorescence of this sensor, and the normal metal cations and near neutral pH show very little interference to its Zn2＋ sensing behavior. Its linear response range to Zn2＋ is 0.12-1.2 μmol-L-1, and the LOD is 0.18 μmol.L-1. Confoeal fluorescence imaging of intracellular Zn2＋ in HeLa cells demonstrated the sensor＇s cell membrane permeability and its reversible cytosolic Zn2＋ imaging ability.