基于吲哚菁的新型pH荧光探针的性能与机理  

Properties and Mechanism of Novel pH Fluorescent Probes Based on Indocyanines

作　　者：冯潇炜 何冬琼 王立升 刘旭 Feng Xiaowei;He Dongqiong;Wang Lisheng;Liu Xu(School of Chemistry and Chemical Engineering,Guangxi University,Nanning 530004,China;School of Medicine,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学化学化工学院,广西南宁530004 [2]广西大学医学院,广西南宁530004

出　　处：《山东化工》2022年第23期154-157,161,共5页Shandong Chemical Industry

基　　金：国家自然科学基金(No.22078073);广西重点研发计划资助项目(桂科AB18221121);广西创新驱动发展专项资金资助项目(桂科AA18242040);广西中药质量标准研究重点实验室开放课题资助项目(桂中重开201703)。

摘　　要：基于吲哚菁设计合成了一种pH荧光探针IC-A并对它的光谱性能以及pH敏感机理进行研究。其中IC-A的最大发射波长为500 nm,斯托克斯位移达到140 nm,pKa为2.50。IC-A对pH非常敏感,在pH值1.0~4.0范围内荧光强度增加10倍,并且在一定范围内荧光强度与pH值呈线性变化。同时IC-A有着良好的抗生物离子或分子干扰的能力,在对荧光可逆性、光稳定性和荧光量子产率等测试中它也表现良好。通过1H NMR谱图和TD-DFT计算分析了IC-A对pH响应的机理,确定了它的pH敏感基团为吲哚菁。吲哚菁基团与质子结合后改变了体系的电荷分布,大共轭结构受到破坏,从而导致荧光淬灭。A pH fluorescent probe IC-A was designed and synthesized based on indocyanine.Then,its spectral properties and pH-sensitive mechanism were studied in this paper.The maximum emission wavelength of IC-A is 500 nm.The Stokes shift reaches 140 nm.The pKais 2.50.IC-A is very sensitive to pH,with a 10-fold increase in fluorescence intensity in the pH value 1.0~4.0 range.The fluorescence intensity of IC-A changed linearly with pH value within a certain range.At the same time,IC-A has good resistance to biological ions or molecular interference,and it also performs well in the tests of fluorescence reversibility,photostability and fluorescence quantum yield.The pH responsive mechanism of IC-A was analyzed by~1H NMR spectra and TD-DFT calculations,and its pH sensitive group was identified as indocyanine.The combination of indocyanine groups with protons changed the charge distribution of the system,and the macroconjugated structure was destroyed,resulting in fluorescence quenching.

关 键 词：PH 荧光探针 TD-DFT 吲哚菁 

分 类 号：O657.3[理学—分析化学]