单激发双发射近红外荧光碳量子点制备、荧光性能与细胞成像

Preparation,Fluorescent Properties and Cell Imaging of Near Infrared Fluorescent Carbon Quantum Dots with Single Excited Double Emission

探索合成方法简单的近红外比率荧光探针具有重要意义。本文以高山榕树叶为碳源,乙醇、丙酮为提取剂,采用溶剂热法于200℃高压反应釜中反应10 h,一步合成具有近红外双发射荧光特性的碳量子点(CDs)。透射电镜(TEM)表明合成的CDs分散性好、平均尺寸约为4.70 nm,晶格常数为0.32 nm。X射线衍射(XRD)结果显示该碳点在2θ=22°附近有一个较宽的衍射峰,表明该CDs为sp^(2)杂化的无定形碳。傅里叶红外光谱(FT-IR)显示其含有氨基、羰基、醇羟基和甲基。荧光光谱表明,最大激发波长410 nm,最大发射波长为466 nm和676 nm。以硫酸奎宁做参比测得荧光量子产率为26.31%。实验还探讨了CDs的酸碱、光学、抗盐和金属离子的稳定性以及细胞成像效果。以上结果表明,该碳点具有原料廉价易得、制作简便、对酸碱稳定、抗光漂白性良好等优点,具有良好的光学成像应用前景。

It is of significance to explore the simple synthetic method and near-infrared ratio fluorescence probe.In this paper,carbon quantum dots(CDs)with near-infrared double-emission fluorescence properties were synthesized by solvothermal reaction in 200℃high pressure reactor for 10 h using Ficus alba leaves as carbon source,ethanol and acetone as extraction agent.Transmission electron microscopy(TEM)showed that the average size of CDs is about 4.70 nm and the lattice constant is 0.32 nm.X-ray diffraction(XRD)results showed there is a wide diffraction peak at near 2θ=22°.It showed the CDs was amorphous carbon sp^(2) hybridized.Fourier transform infrared spectroscopy(FT-IR)indicated the CDs had amino,carbonyl,alcohol hydroxyl,and methyl.Fluorescence spectra showed that the maximum excitation wavelength was 410 nm,and the maximum emission wavelength was 466 nm and 676 nm.Using quinine sulfate as a reference,the fluorescence quantum yield was 26.31%.The stability of acid-base,optical,salt resistance and metal ion resistance and the effect of cell imaging were also discussed.The above results show the CDs has the advantages of cheap raw materials,easy to produce,stable to acid and alkali,good photobleaching resistance and so on.It has good prospects for optical imaging applications.