高分子水凝胶修饰碳纳米管神经元探针

【作者】 林德盟；

【导师】 车剑飞；

【作者基本信息】 南京理工大学 ， 材料学， 2010， 硕士

【摘要】 本文主要研究了聚乙二醇二丙烯酸酯／单壁碳纳米管(PEGDA/SWNTs)水凝胶膜层对金电极的修饰,考察了水凝胶修饰电极的电化学性能。同时,在PEGDA/SWNTs水凝胶膜层中负载地塞米松,研究了其药物释放规律。采用共价键合法对金电极进行化学修饰,将清洁处理的金电极采用层层组装的方法,分别经过巯乙胺和PEGDA大分子的修饰,在金电极表面制得以乙烯基封端的分子膜。利用接触角、x射线光电子能谱(xPS)和循环伏安曲线(CV)的测试手段证实了巯乙胺的自组装和Michael加成反应的成功进行,为电极的进一步修饰提供了可能。将化学酸化处理的SWNTs超声分散在PEGDA水凝胶的前驱物溶液中,用微量注射器滴加到分子修饰的金电极表面,采用UV紫外光聚合法制得了水凝胶修饰电极。采用循环伏安法(CV)和交流阻抗谱(EIS)表征了水凝胶修饰电极的电化学性能,发现SWNTs能显著提高水凝胶修饰膜层的导电性能；并比较了共价键合法和涂渍法制得的水凝胶修饰电极的膜层粘结强度,结果表明共价键合法优于涂渍法。将地塞米松掺杂于PEGDA水凝胶前驱物溶液中,PEGDA在UV紫外光下照射固化过程中使药物负载在三维网络结构中,表征了水凝胶薄膜的物理化学性质,并研究了水凝胶的药物释放规律,发现SWNTs对地赛米松具有固定吸附的作用,延长了地塞米松在水凝胶中的释放周期。更多还原

【Abstract】 In this paper, gold electrode was modified with polyethylene glycol diacrylate/single-walled carbon nanotubes (PEGDA/SWNTs) hydrogel coating. Electrochemical properties of the hydrogel-modified electrode as well as mechanisms of the drug release from PEGDA/SWNTs hydrogel coating were investigated.The gold substrate was chemically modified by covalent binding. The fabrication was performed in in-situ layer-by-layer assembly method. First the surface of the cleaned and activated gold substrate was chemically modified with cysteamine, followed by Michael addition between PEGDA and cysteamine to introduce pendant vinyl surface functionalities on the surface of gold electrode. The self-assembly of cysteamine and Michael addition were demonstrated by contact angle, X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV).After acid treatment, the shortened SWNTs were dispersed in PEGDA hydrogel precursor mixture by ultrasonication. The mixture was spread evenly onto the molecular-modified gold electrode with a microsyringe, followed by ultraviolet irradiation for photopolymerization. The electrochemical properties of the resulted hydrogel-modified electrode were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It was found that SWNTs enhanced the conductivity of the hydrogel coating. Furthermore, adhesive strength of the hydrogel coating on the hydrogel-modified electrode made by covalent binding and dip-coating was carried out separately. The results showed that covalent binding had a better adhesive strength compared to dip-coating.For doping drug into three-dimensional network structure, dexamethasone was dissolved in PEGDA hydrogel precursor mixture, and the mixture was photopolymerized under ultraviolet irradiation. The physical and chemical properties of the hydrogel coating as well as the mechanisms of the drug release from the hydrogel were investigated. It was found that SWNTs had some sorption on dexamethasone, prolonged the release period of dexamethasone from hydrogel.更多还原