基于果糖和多巴胺的碳点制备及性能

Preparation and properties of carbon dots based on fructose and dopamine

以果糖为碳源,多巴胺(DA)为氮源,一步水热法制备N掺杂碳点(N-CDs).分别采用X-射线衍射仪(XRD)、高分辨透射电子显微镜(HR-TEM)、X射线光电子能谱仪(XPS)、紫外-可见吸收光谱(UV-Vis)和傅里叶变换红外光谱仪(FT-IR)等表征手段对N-CDs的结构、形貌、表面官能团及光学性质进行分析,用MTT法研究细胞毒性,用共聚焦显微技术研究细胞成像性能.结果表明:N-CDs为平均粒径约1.76 nm的球形颗粒,表面富含羟基、羧基、氨基和羰基等官能团,荧光激发和发射波长分别为440 nm和536 nm.N-CDs水溶性好,低细胞毒性,浓度为0.5 mg‧mL^(-1)时,Hela细胞的存活率高于93%,且N-CDs易通过细胞膜进入细胞质中,在细胞内展现出较亮的荧光信号.该方法简便、绿色环保,N-CDs具有低细胞毒性,可在细胞内荧光成像,有望应用于癌细胞的早期诊断.

Nitrogen doped carbon dots(N-CDs)were synthesized via one-step hydrothermal method using fructose as carbon source and dopamine(DA)as nitrogen source.The structure,morphology,surface functional groups and optical properties of N-CDs were characterized via X-ray diffraction(XRD),high-resolution transmission electron microscopy(HRTEM),X-ray photoelectron spectrometer(XPS),ultraviolet-visible absorption spectrum(UV-vis),Fouriertransform infrared spectroscopy(FT-IR)and other characterization techniques.The cytotoxicity was studied by MTT assay,and cell imaging performance was studied by confocal microscopy.The results showed that the N-CDs were spherical particles with an average particle size of about 1.76 nm.The surface was rich in functional groups,such as hydroxyl,amino,carboxyl and carbonyl groups.The fluorescence excitation and emission wavelengths of the N-CDs were 440 nm and 536 nm,respectively.The N-CDs demonstrated good water solubility and low cytotoxicity.At a concentration of 0.5 mg∙mL^(-1),the survival rate of Hela cells was higher than 93%.N-CDs could easily enter the cytoplasm through the cell membrane and showed bright fluorescence signal in the cell.This method is simple,green and environmentally friendly.The N-CDs have low cytotoxicity and can be used in intracellular fluorescence imaging,which is highly desirable for the early diagnosis of cancer cells.