Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.
Institute of Nanochemistry and Nanobiology, Shanghai University, Shanghai 200444, China.
J Nanosci Nanotechnol. 2019 Apr 1;19(4):2130-2137. doi: 10.1166/jnn.2019.15807.
Carbon dots (CDots) in a general structure of small carbon nanoparticles with various surface passivation schemes have emerged to represent a new class of carbon nanomaterials in now a rapidly advancing and expanding research field. Among various synthesis methods, the use of pre-processed and selected small carbon nanoparticles for deliberate chemical functionalization of the particle surface with organic molecules have produced high-performance and structurally better defined CDots. Specifically, small organic molecules 2,2'-(ethylenedioxy)bis(ethylamine) and 3-ethoxypropylamine were used for the effective surface passivation of the carbon nanoparticles via chemical functionalization to yield CDots that are brightly fluorescent and also structurally ultra-compact, amenable to various desired cell imaging applications. Thus, a systematic evaluation of these CDots on their cytotoxicity profiles is necessary, and performed in this study by using a diverse selection of cell lines. Also for fluorescence imaging, CDots were modified with their encapsulating selected organic dyes for much enhanced red/near-IR fluorescence emissions. These modified CDots with the dyes as guest were also evaluated for their cytotoxicity profiles. The results suggest that the CDots without and with the guest dyes are generally nontoxic to the selected cell lines, further supporting the notion that CDots can be used as high-performance yet nontoxic bioimaging agents.
碳点（CDots）是一类具有各种表面钝化方案的小碳纳米粒子的通用结构，代表了一个在快速发展和不断扩展的研究领域中的新型碳纳米材料。在各种合成方法中，使用预处理和选择的小碳纳米粒子对粒子表面进行有机分子的故意化学功能化，已经产生了高性能和结构更好定义的 CDots。具体来说，小分子 2,2'-(乙二氧基)双(乙胺)和 3-乙氧基丙胺被用于通过化学功能化对碳纳米粒子进行有效的表面钝化，得到的 CDots 具有明亮的荧光，并且结构超紧凑，适用于各种所需的细胞成像应用。因此，有必要对这些 CDots 进行系统的细胞毒性评估，本研究使用了多种细胞系进行了这项评估。同样，为了荧光成像，CDots 被其包裹的所选有机染料进行了修饰，以增强红色/近红外荧光发射。还对这些带有染料作为客体的修饰 CDots 进行了细胞毒性评估。结果表明，没有和带有客体染料的 CDots 对所选细胞系通常是无毒的，进一步支持了 CDots 可用作高性能但无毒的生物成像剂的观点。
