混合短链 PEG 硫醇自组装膜制备与蛋白质固定

摘要

采用自组装技术制备了一系列在金表面不同摩尔比的 PEG 硫醇混合自组装膜，并将蛋白质共价固定在膜表面。通过 AFM、接触角测试仪和 XPS 技术对混合自组装膜和蛋白质接枝反应后表面的物理和化学性质进行了分析表征。通过抗原-抗体反应实验检验了蛋白质膜表面生物活性的相对大小。结果表明：自组装膜表面的比例组成与溶液中的组成并不完全一致。接枝后蛋白质的形貌及蛋白质膜表面粘附力分布与自组装膜的表面组分有关并会影响其与抗体的反应活性。当反应溶液中 SH-PEG-OCH3/SH-PEG-COOH 摩尔比为1∶6时，所形成的自组装膜的表面羧基含量最大，同时粘附力也达到最高值，蛋白质活性也最大。%A series of mixed PEG self-assembled monolayer (SAM)on gold surface was prepared by varying the ratios of SH-PEG-OCH3 /SH-PEG-COOH in the solution.The protein molecules were immobilized to the surface of the mixed monolayers by covalent reaction.The surface physical and chemical properties of the mixed monolayers were characterized by AFM,contact angle and XPS techniques.The relative bioactivities of the protein film were tested by antigen-antibody reaction experiment.The results show that the ratio of PEG mixed monolayer is different from that in the preparation solution.The morphology and adhesion properties of the immobilized protein surfaces are influenced by the ratios of two PEG molecules and can influence the bioactivities of the protein films.When the molar ratio of SH-PEG-OCH3 /SH-PEG-COOH in the solution is 1 ∶6,the mixed monolayer prepared has not only highest amount of carboxyl groups but also biggest adhesion force.