文献：Highly biocompatible graphene quantum dots: green synthesis, toxicity comparison and fluorescence imaging

文献链接：https://link.springer.com/article/10.1007/s10853-019-04079-2

作者：Chaoren Yan , Xiaoling Hu , Ping Guan, Tongtong Hou, Peng Chen, Dewei Wan, Xinli Zhang, Jian Wang , and Chaoli Wang

相关产品：CGQDs 石墨烯量子点

原文摘要：Graphene quantum dots (GQDs) have tremendous potential in biological imaging

due to their bright visible photoluminescence mission. However, the tedious preparation procedures and potential toxicity of GQDs greatly limit their application in biological field. Here, highly biocompatible GQDs (HGQDs) have been successfully prepared only by glucose in aqueous solution. Compared with GQDs prepared from conventional methods (CGQDs), the cytotoxicity of HGQDs reduced by more than 60%, and the flow cytometric analysis of the normal cells

treated with HGQDs showed that the early and late apoptotic rate reduced by more than 72% and 40%, respectively. In vitro fluorescence imaging showed that both cells and bacteria could be imaged by HGQDs, and the morphology of cells and bacteria could be kept to a maximum extent. A long-term in vivo study revealed that no obvious organ (heart, liver, spleen, lung and kidney) damage or lesions were observed, and the blood–brain barrier (BBB) could be overcome,

which provides the possibility for treatment and diagnosis of brain-related diseases. With

adequate studies of biocompatibility, both in vitro and in vivo,HGQDs may be considered for further biological application.

石墨烯量子点是一种纳米材料，通常呈现出纳米级的尺寸，一般在几个到几十个纳米之间。外观上可能为黑色或深色的粉末状或胶体状物质。石墨烯量子点具有良好的光学性能，如强荧光发射，其荧光波长可通过控制量子点的尺寸和化学结构进行调节，可发出从蓝色到近红外的不同颜色的光。它还具有良好的导电性和导热性，以及较高的化学稳定性和机械强度。

石墨烯量子点在生物医学方面可用于生物成像，其荧光特性能够清晰地显示细胞和组织的结构；还能作为药物载体，实现药物的靶向输送和控制释放。在传感器领域，可用于检测各种化学物质和生物分子，具有高灵敏度和选择性。在高生物相容性的葡萄糖在水溶液中制备了GQDs（HGQDs）可以降低有害性。从葡萄糖中合成HGQDs的方法如下：

图：HGQDs的合成路线及其生物成像过程的说明

将纳米石墨粉投入硫酸与硝酸的混合酸中，超声处理后，在微波的照射下，加热进行反应。将反应产物先用微孔膜过滤，收集滤液中和至中性后，再用截留分子量的透析袋透析若干次，收集袋内液体，即可得到石墨烯量子点。将得到的石墨烯量子点的 pH 值调至 13 后，在微波的照射下，加热反应，可得到具有白色荧光发射性能的石墨烯量子点混合物。将葡萄糖分散在去离子水中，在室温搅拌。然后，将混合物倒入不锈钢高压釜中小时。通过过滤和离心得到最终的棕色液体。

图：HGQDs和葡萄糖的原子百分比。

结论：高生物相容性的葡萄糖在水溶液中制备的GQDs（HGQDs）。与常规方法（CGQDs）制备的GQDs相比，HGQDs的细胞有害性降低了60%以上，流式细胞仪分析对HGQDs处理的正常细胞的检测结果显示，早期和晚期Apoptosis 率分别降低了72%和40%以上。体外荧光成像结果显示，HGQDs可以对细胞和bacteria进行成像，并能最大限度地保持细胞和bacteria的形态。长期的体内研究显示，未见明显的器官损伤或病变，可克服BBB。