Feng Ji, Wang Wen-Jing, Hai Xin, Yu Yong-Liang, Wang Jian-Hua
Research Center for Analytical Sciences, College of Sciences, Northeastern University, Box 332, Shenyang 110819, China.
J Mater Chem B. 2016 Jan 21;4(3):387-393. doi: 10.1039/c5tb01999k. Epub 2015 Dec 10.
Carbon dots (CDs) with a high quantum yield have been synthesized by a facile and green one-pot approach under microwaves with silkworm chrysalis (SC) as the natural carbon source, without using any other chemicals/reagents. The morphology and optical properties of the resultant CDs are characterized by TEM, XRD, FT-IR, XPS, UV-vis and photoluminescence (PL). The SC-CDs have an average size of 19 nm, and contain C, O and N with relative contents of ca. 71.32%, 22.96% and 5.72%, respectively. A significant emission at 420 nm at an excitation wavelength of 350 nm is recorded, resulting in a quantum yield of 46% with quinine sulfate (quantum yield 54%) as a reference. In addition to excellent solubility and stability in aqueous medium, the SC-CDs exhibit excitation-dependent photoluminescence with a large Stokes shift of 70 nm. It is further demonstrated that the SC-CDs exhibit a low cytotoxicity at a higher concentration of 15 mg mL and they are able to display bright blue, green and red colors under an inverted fluorescence microscope during cell imaging experiments, showing their vast potential in bioimaging.
以蚕蛹（SC）为天然碳源，在微波作用下通过简便绿色的一锅法合成了具有高量子产率的碳点（CDs），无需使用任何其他化学物质/试剂。通过透射电子显微镜（TEM）、X射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）、X射线光电子能谱（XPS）、紫外可见光谱（UV-vis）和光致发光（PL）对所得碳点的形貌和光学性质进行了表征。蚕蛹碳点（SC-CDs）的平均尺寸为19 nm，含有C、O和N，相对含量分别约为71.32%、22.96%和5.72%。在350 nm激发波长下，在420 nm处记录到显著发射，以硫酸奎宁（量子产率54%）为参比，量子产率为46%。除了在水介质中具有优异的溶解性和稳定性外，蚕蛹碳点还表现出激发依赖的光致发光，斯托克斯位移为70 nm。进一步证明，蚕蛹碳点在15 mg/mL的较高浓度下表现出低细胞毒性，并且在细胞成像实验中，它们能够在倒置荧光显微镜下呈现明亮的蓝色、绿色和红色，显示出其在生物成像方面的巨大潜力。
