Theoretical studies on force titration of amino-group-terminated self-assembled monolayers

• Main Authors: Wang, Junmei, Zhang, Hua, He, Hui-Xin, Hou, Tingjun, Liu, Zhong-Fan, Xu, Xiaojie
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2012
• Subjects: DRNTU::Science::Biological sciences::Biochemistry
• Online Access: https://hdl.handle.net/10356/95785; http://hdl.handle.net/10220/8322
• Institution: Nanyang Technological University

The structures of (3-aminopropyl)triethoxysilane (APTES), 4-aminothiophenol (4-ATP) and 4-mercaptopyridine (4-MP) self-assembled monolayers (SAMs) are studied by quantum mechanics in order to explain the force titration curves of these amino-group-terminated SAMs. The surface charges and electrostatic surface potentials derived from the ab initio calculations can give satisfactory explanations for the experimental results. We also propose a simple model to simulate the force titration process. The force between the tip and sample can be estimated according to the slope coef®cient of the curve of energy versus distance. This curve can lead to a better understanding of the force titration curves of amino-group-terminated SAMs.