一种检测活细胞内铜离子的“关-开”型近红外荧光探针

An “Off-On” Near-Infrared Fluorescent Probe for Cu^2+ Detection in Living Cells

以2-[6-(N,N-二甲胺基)萘基]-7-羟基-4H-色酮为荧光报告基团,2-吡啶甲酸酯为识别基团,设计合成了一种可识别铜离子的近红外荧光探针(6),并用1H NMR、13C NMR、MS和元素分析进行了结构鉴定.该探针能够快速地与Cu2+发生特异性反应,655 nm处荧光强度明显增加,同时肉眼可见溶液颜色发生改变.在0~2.0×10^-5 mol/L内,荧光强度和Cu^2+浓度呈现良好的线性关系,检测限为3.2×10^-8 mol/L.机制研究表明,Cu^2+可使探针的酯键发生特异性断裂,生成具有强荧光的2-[6-(N,N-二甲胺基)萘基]-7-羟基-4H-色酮(5).此外,该探针可用于活细胞中铜离子荧光成像.

A near-infrared fluorescent probe(6)was designed and synthesized by using 2-(6-(dimethylamino)naphthalen-2-yl)-7hydroxy-4 Hchromen-4-one as report group and 2-picolinate as recognition group.The probe was identified by 1 H NMR,13C NMR,MS and elemental analysis.The probe could react specifically with Cu^2+and its fluorescence intensity increased obviously at 655 nm,at the meantime,the color change of the solution can be seen by naked eyes.A linear relationship was obtained between the fluorescence intensity and concentration of Cu^2+in the range of 0~2.0×10^-5 mol/L,and the detection limit was 3.2 X 10^-8 mol/L.The mechanism study showed that Cu^2+catalyzed the cleavage of the ester bond and strongly fluorescent 2-[6-(N,N-dimethylamno)naphthyl]-7-hydroxy-4 H-chromen-4-one(5)was generated.In addition,the probe 6 could be used for fluorescence imaging of Cu2+in living cells.