Functionalizable Antifouling Zwitterionic Self-Assembled Monolayer for Biosensor Application

• Main Authors: Yu-Sin Wang, 王裕昕
• Other Authors: Chun-Jen Huang
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/mk2v4y

碩士 === 國立中央大學 === 生醫科學與工程學系 === 105 === Reducing nonspecific interaction of biomolecules with an electrode is a key issue for increasing sensitivity and specificity for biosensors. Zwitterionic materials, carrying both positively and negatively charged moieties in a molecule, have shown excellent biocompatibility by resisting undesired biomolecules adsorption. In particular, zwitterionic carboxybetaine materials are the most attractive. Besides the high resistance to nonspecific biomolecules adsorption, the carboxylic acid group can be transformed to functionalizable intermediates to create a ligand-functionalized substrate. Self-assembled monolayers (SAMs) are well-established as a means to selectively modify surfaces to achieve desired chemical and physical properties. In this study, we used carboxybetaine and sulfobetaine terminated alkanethiol to form mixed SAMs on gold surface. The zwitterion terminated mixed SAMs can provide functionalizable antifouling properties. X-ray photoelectron spectroscopy showed the molar ratio of carboxybetaine and sulfobetaine terminated alkanethiol molecular mixing in solution was in agreement with the feed-in molecules ratio. It supported that the composition of the surface molecules can be controlled by varying feed-in molar ratio in the solution. Surface plasmon resonance biosensor showed that there were the best ability of anti-fouling when carboxybetaine and sulfobetaine terminated alkanethiol mixed SAM with a molar ratio of 1 : 9. Under this condition, we can successfully attach the antibody on the surface via amino-coupled NHS / EDC chemical modification. Then, the surface was applied to the surface plasmon resonance sensor. The limit of detection was 80 ng/ml. The new type of biosensor interface offers anti-fouling properties and functionalizable capacity. It can meet the needs of the market to facilitate the development of biological sensors