【作者】 高昕； 郭祥峰； 贾丽华；

【Author】 Xin Gao;Xiangfeng Guo;Lihua Jia;The Key Laboratory of Fine Chemicals of College of Heilongjiang Province,College of Chemistry and Chemical Engineering,Qiqihar University;

【机构】 黑龙江省高校精细化工重点实验室齐齐哈尔大学化学与化学工程学院；

【摘要】 荧光碳点具有典型的纳米结构、易于表面功能化、光稳定性好、低毒、生物相容性好等优良特性[1],已被深入研究,并广泛应用于生物医学成像、光催化、传感器和能量转换等领域[2]。按照文献[3],以柠檬酸和尿素为原料通过微波法合成了荧光碳点(CDs),作为参比荧光碳点。参照上述方法,在制备荧光碳点的过程中进一步掺杂化合物2-甲基-N-柠檬酰基苯胺作为原位修饰试剂,合成了修饰的荧光碳点(m-CDs)。用透射电子显微镜(TEM)和傅立叶红外光谱(FT-IR)对m-CDs进行了形貌和表面官能团表征。TEM照片显示,m-CDs的直径在1～7nm之间,呈球形,可确定其为纳米碳点。FT-IR表明m-CDs表面含有丰富的-COOH、-OH和-NH等官能团,有利于金属离子与荧光碳点的配位结合。利用紫外-可见吸收光谱和荧光光谱测定了CDs和m-CDs的光谱和识别性能。结果表明,m-CDs的荧光与CDs相似,发射波长具有激发波长依赖性;另外,在常见金属离子中,m-CDs与CDs都选择性荧光猝灭识别Fe3+和Hg2+,但修饰使其荧光猝灭率分别由45%和35%提升至63%和52%。这是由于金属离子与m-CDs表面丰富的官能团结合导致荧光被有效淬灭。更多还原

【Abstract】 Fluorescent carbon dots are widely studied and used for medical bioimaging, photocatalysis, sensors, energy conversion and other fields due to their excellent nanostructure, easy surface functionalization, stable optical properties, low toxicity,good biocompatibility and other excellent characteristics. According to the literature, fluorescent carbon dots(CDs) were synthesized by microwave method using citric acid and urea as raw materials, and it is used as contrast fluorescent carbon dots. Referring to the above method, the modified fluorescent carbon dots(m-CDs) were synthesized by further doping the compound 2-methyl-N-citrylaniline as an in-situ modification reagent in the preparation of fluorescent carbon dot synthesis. The morphology and surface functional groups of m-CDs were characterized by transmission electron microscopy(TEM) and Fourier transform infrared spectroscopy(FT-IR). The TEM photo shows that the diameter of m-CDs is between 1 and 7 nm, and they are spherical, could be determined to be nano-carbon dots. The infrared spectrum shows that there are rich functional groups such as-COOH,-OH,-NH on the surface of the m-CDs, which is more conducive to the coordination of metal ions and carbon dots. The spectra and recognition properties of CDs and m-CDs were determined by UV-Vis absorption spectroscopy and fluorescence spectroscopy. The results show that the fluorescence of m-CDs is similar with CDs, and the emission wavelength has excitation wavelength dependence; In addition, in common metal ions, both m-CDs and CDs selectively fluoresce to identify Fe3+ and Hg2+, but the modification increases respectively the fluorescence quenching rate from 45 % and 35 % to 63 % and 52 %. This is due to the fact that the metal ions combine with the rich functional groups on the surface of m-CDs, resulting in efficient quenching of the fluorescence.更多还原