Preparation of mixed monolayer for biomolecule immobilization

• Main Authors: Mei-Yi Tsai, 蔡美儀
• Other Authors: Yu-Tai Tao
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/64838898703846894948

碩士 === 國立中央大學 === 化學研究所 === 92 === In this study three kinds of binary mixed self-assembled monolayers were prepared on gold：p-mercaptobenzoic acid/4-methoxy-benzenethiol, 4-mercaptomethylbenzoic acid/4-mthoxybenzyl mercaptan, and 4-mercaptomethyl-benzoic acid/benzylmercaptan. The surface structure and distribution of the films were analyzed in order to prepare a randomly distributed carboxyl functional groups on surface. The carboxyl groups were used to immobilize ssDNA through amide linkage via chemical transformation. The ssDNA-attached surface was used to capture a complimentary DNA via hybridization. The compositions of mixed-monolayers and the chemical transformation of the surface functional groups were studied by reflection absorption infrared spectroscopy, ellipsometry, NEXAFS. The mixed SAMs prepared from 4-mercaptomethylbenzoic acid/benzylmercaptan by kinetical trapping method was activated by NHS/EDC to form the NHS-ester, which reacted with an amine-modified probe DNA to attach the single strand DNA in various concentrations on surface. Hybridization with a target DNA was measured by fluorimeter. Maximum loading of the target DNA was observed for a surface prepared from a solution containing 4-mercaptomethylbenzoic acid and benzylmercaptan in 1:9 ratio. II