高生物相容性氮掺杂碳点的合成及其在生物成像中的应用

以柠檬酸为碳源且以不同氨基酸为氮源，在无任何催化剂的条件下通过一步水热合成法合成氮掺杂碳点。预实验表明，以精氨酸为氮源的荧光碳点(CDs-Arg)以相对较高的荧光量子产率(33.25%)被选为进一步的研究对象。进一步通过一系列光谱、电位、粒径、电镜、X射线、元素分析等实验对其理化性质进行表征。同时也考察了CDs-Arg纳米颗粒在不同激发光、温度、pH或氧化还原条件下的稳定性。并通过MTT实验和体内分布实验考察了其细胞毒性和体内代谢分布情况。上述实验证明，该氮掺杂碳点具有较高的荧光效率和较好的稳定性及极低的毒性，这些对其生物成像应用提供了基础。最后，对于这种水溶性小颗粒CDs-Arg纳米粒的生物分布研究表明，该纳米粒可通过肾小球排出体外。这些结果表明CDs-Arg纳米颗粒是一种高生物相容性的纳米粒，并具有生物成像和监测药物代谢的应用潜力。

Synthesis of high biocompatible nitrogen-doped carbon dots for staining in bio-imaging

With citric acid as carbon source and different amino acids as nitrogen source, the nitrogen-doped carbon was synthesized by one-step hydrothermal method under the condition of no catalyst. The pre-experiments show that arginine-doped carbon dots(CDs-Arg)with relatively high fluorescence quantum yield(33. 25%)were picked out for further study. Furthermore, we studied the physical and chemical properties of CDs-Arg through a series of spectral, electric potential, particle size, X ray and elemental analysis experiments. At the same time, the stabilities of the nanoparticles towards different pH, temperatures, excitation lasers or redox conditions were studied. And the MTT and in vivo distribution experiments were also conducted for the toxicity and metabolism studies. The experimental results showed that the arginine doped carbon dots has high fluorescence efficiency, good stability, and extremely low toxicity. And the water-soluble small particles of CDs-Arg nanoparticles showed that the nanoparticles can be excreted through the glomerulus. These results show that the CDs-Arg Nanoparticles are biocompatible nanoparticles and have potential applications in biological imaging and can serve as a monitor of drug metabolism.