本研究目的為建立具功能化和低非特異生物分子吸附特性之生物感測器介面。減少非特異性（nonspecific）生物分子與電極之間的相互作用，是提升生物感測器靈敏度和專一性之關鍵因素。而一個分子上同時帶有正電荷及負電荷基團的兩性雙離子材料，因為其具有良好的生物相容性（biocompatibility）以及抵抗非特異性生物分子吸附之特性，所以常被應用於生醫領域上。在雙離子材料內，最特別的就是羧基甜菜鹼（carboxybetaine）材料，除了具備良好抗生物分子吸附的特性之外，羧基甜菜鹼分子上羧酸官能基（carboxylic acid）可被轉化為功能化中間體，以建立配體功能化之表面。自組裝單層（Self-assembled monolayer, SAM）是一種已被確立的表面改質材料，可選擇性地修飾表面以獲得期望的化學和物理性質。本研究是利用羧基甜菜鹼烷烴硫醇（carboxybetaine alkanethiolate）與磺酸甜菜鹼硫醇分子混合共同修飾在金表面上，以同時提供表面良好的抗非特異性吸附和功能化之特性。由高解析電子能譜儀表面分析的實驗結果發現，羧基甜菜鹼硫醇與磺酸甜菜鹼硫醇分子其溶液混合的比例與表面的組成比例相似，可藉由改變溶液的組成比例來控制表面分子的組成。表面電漿共振（Surface plasmon resonance, SPR）生物感測器結果顯示，當羧基甜菜鹼硫醇與磺酸甜菜鹼硫醇分子以1：9的莫爾比例混合修飾時，所表現出的抗沾黏能力最為優異。且在該混和比例下，進行氨基偶聯NHS/EDC化學改質能夠成功的使抗體固定化於表面上。並且將此表面應用於表面電漿共振感測器，測得此系統下的感測器最低檢測濃度為80 ng/ml。此種新型的生物感測器介面，讓生物感測器具有良好的抗非特異性吸附性質以及賦予感測器多功能化的能力，能因應目前市場所需，以利於生物感測器發展。;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
