一种香豆素-吲哚类氰离子荧光探针的理论研究

Theoretical study on a coumarin-indole based fluorescent probe for cyanide ion

为了开发新型氰离子荧光探针,采用量子化学计算方法、密度泛函理论对一种新型香豆素-吲哚类荧光探针M+1及其与CN-的加成物M1-CN的优化构型、吸收光谱、激发光谱进行了研究,并讨论该探针应用于氰离子检测的光物理机制.结果显示:M1^+最大发射光谱为766nm,处于近红外区;M1-CN的最大发射光谱为285nm,该探针与CN-加成后发射光谱发生了非常显著的蓝移;激发态下M1^+和M1-CN的前沿轨道形状差异较大.表明M+1可作为检测CN-的高灵敏荧光探针,并可用于生物医学光学成像剂.

In order to develop new fluorescent probes for cyanide ion,a novel coumarin-indole based fluorescence probe M1^+ was studied theoretically by using quantum chemical calculation and density functional theory.The structures of M1^+ and its adduct with cyanide ion(M1-CN) were optimized;the absorption and fluorescence spectra of M1^+ and M1-CN were simulated;and the photophysical mechanism of M1^+ for the detection of cyanide ion was discussed.The results showed that the maximum emission of M1^+ was 766 nm,which was in the near-infrared region;the maximum emission of M1-CN was 285 nm.It was found that adding cyanide ion to the probe led to a very significant blue-shift in fluorescence spectrum;the frontier orbitals of M1^+ in the excited states were quite different in shapes from those of M 1-CN.It indicated that M1^+ could be used as a highly sensitive fluorescent probe for the detection of cyanide ion as well as an agent in biomedical optical imaging.