石墨烯是近年来发现的一种新型碳基单原子层二维晶体材料，具有独特的结构和性 质，以其为基础的功能化改性，进而对其应用领域的不断拓展和完善成为近年来一大研究 热点。石墨烯的改性及在生物医学领域的应用，特别是改性石墨烯作为药物载体的深入研 究尤其值得关注。深入研究和探讨对石墨烯功能化修饰及改性的方法，揭示载药传递、释 放的机理、代谢途径及细胞、分子机制，依然是一项极具价值及挑战性的课题。本文正是 基于这种现状，以氧化石墨烯（GO）为主要的研究对象，对其制备、改性以及载药的可行 性进行了深入探讨。本文的主要工作内容如下， 1. 通过将传统的Hummers法进行改良，增加了1000℃下的高温膨化天然鳞片石墨粉和 预氧化两个步骤，制备得到了含氧量达57.59%的氧化石墨烯。采用傅里叶红外光谱扫描仪 （FTIR）、原子力显微镜（AFM）、拉曼光谱分析仪（Raman）以及X-射线粉末衍射仪（XRD） 对其化学组分、形貌和结构进行表征，结果表明所制备的氧化石墨烯的厚度约为1nm，说 明制备得到单层的氧化石墨烯。其片层大小从几百纳米到几微米不等，片层之间有叠加情 况发生。 2. 利用细胞破碎仪对GO水溶液进行超声破碎，得到了粒径均一，且氧化石墨片层无 叠加状况的稳定分散液，通过反复实验，基本实现了制备粒径在100~500nm粒径可控的氧 化石墨烯分散液。 分别接枝PEG或氨基化PEG实现对GO的官能团修饰。实验结果表明，功能化后能显著 改善GO在磷酸盐缓冲溶液（PBS）以及细胞培养液（MEMɑ）中的溶解性和稳定性。通过 体外细胞实验研究GO-PEG对成骨细胞（MC3T3）的影响。结果表明，在浓度为5ug/mL时， 培养7天，细胞的增长率为93.2%，说明其不具有明显的细胞毒性。 3. 通过酰胺反应将叶酸（FA）接枝于GO，采用FTIR及紫外分光光度仪等表征手段， 证明复合物接枝成功。考察不同浓度的GO - FA、GO溶液对乳腺癌细胞（MCF-7）的细胞 毒性，以空白组做对照，当培养52小时后，大部分细胞生长良好，浓度为5ug/mL的GO-FA 培养液对MCF-7的相对细胞存活率为85.7%，随着时间的延长，GO-FA显示出对细胞的高 亲和性，这说明了复合物载体不仅是低细胞毒性而且具备一定的靶向性。 关键词，氧化石墨烯 功能化修饰 聚乙二醇 叶酸 细胞相容性暨南大学硕士学位报告 IV Abstract Graphene has been discovered in recent years, which is a new kind of carbon based single atomic layer two-dimensional crystal material with unique structure and properties. Modification of graphene has attracted a lot of attentions in many fields. In biomedical field, modified grapheme has been widely used as drug carrier. Intensive study of the modification of graphene and the mechanism of drug delivery, release mechanism, metabolic pathway, cell and molecular mechanism is still a challenging task. Based on this state, this article deeply studied the preparation and modification of graphene oxide (GO) and its feasibility as drug carrier. The main contents are as follows: 1． Traditional Hummers method was improve for the preparation of GO. The natural flake graphite powder is expanded at 1000℃ and pre-oxidized, graphene oxide with content of 57.59% oxygen is obtained. The chemical composition, morphology and structure is characterized by FTIR, AFM, Raman spectroscopy and XRD. The results show that the thickness of graphene oxide is about 1 nm, indicating its single-layer structure. The size spans from a few hundred nanometers to a few micrometres and there is superposition between the layers. 2. The GO aqueous solution is ultrasonicated by cell broken instrument. The GO dispersion is obtained with uniform particle size. Through repeated experiments, the particle size in dispersion can be controlled raging from 100 to 500 nm. The GO is functional modified by grafting PEG or amino PEG. The solubility and stability of modified GO in PBS and MEMα can be significantly improved. In addition, the cytotoxicy of GO-PEG is tested by in-vitro incubation of MC3T3. The result shows when the concentration is 5ug/ml, the cell growth rate is 93.2% with 7 days culture, indicating no obvious cytotoxicity. 3. Grafting FA onto GO by means of amide reaction, which was proved by means of FTIR and UV spectrophotometry. The cytotoxicity of different concentrations of GO-FA of MCF-7 is studied. After incubation of 52h, most cells grow well. When the concentration is 5ug/ml, the cell survival rate is 85.7%. With the extension of time, GO-FA shows high affinity on cell. This indicates the complex carrier is not only low cytotoxicity, but also has a certain biological targeting effect.暨南大学硕士学位报告 V Key words: graphene oxide functional modification Polyethylene glycol folic acid cytocompatibility暨南大学硕士学位报告 VI 目 录 摘要 …..….II Abstract..IV 第一章 绪论 ….…....1 摘要..............................................................................................................................................II 第一章 绪论.................................................................................................................................1 1.1 石墨烯..............................................................................................................................1 1.1.1 石墨烯简介...........................................................................................................1 1.1.2.石墨烯的制备方法................................................................................................1 1.2. 氧化石墨烯.....................................................................................................................4 1.2.1. 氧化石墨烯简介..................................................................................................4 1.2.2 氧化石墨烯的结构...............................................................................................5 1.2.3. 石墨烯的功能化修饰..........................................................................................6 1.3. 石墨烯在生物医药方面的应用.....................................................................................9 1.3.1 石墨烯在药物和基因运输中的应用.................................................................10 1.4. 本文的设计思路、研究方案和创新点.......................................................................12 1.4.1 本文的设计思路.................................................................................................12 1.4.2 本文的创新点.....................................................................................................13 第二章 氧化石墨烯的制备.........................................................................................................15 2.1 前言................................................................................................................................15 2.2主要实验数据及仪器......................................................................................................16 2.2.1 实验试剂.............................................................................................................16 2.2.2 实验仪器...........................................................................................................16 2.3 实验方法........................................................................................................................17 2.4 表征方法........................................................................................................................17 2.4.1 傅立叶变换红外光谱分析（FTIR)...................................................................17 2.4.2 X射线衍射测试 ...................................................................................................17 2.4.3 原子力显微镜.....................................................................................................18 2.4.4 拉曼表征（Raman）..........................................................................................18暨南大学硕士学位报告 VII 2.4.5 元素分析仪.........................................................................................................18 2.5 结果与讨论....................................................................................................................18 2.5.1 氧化石墨烯的含氧量分析.................................................................................18 2.5.2 氧化石墨烯的红外光谱.....................................................................................19 2.5.3 氧化石墨烯的X-射线衍射分析..........