Probing carboxylic acid groups in replaced and mixed self-assembled monolayers by individual ionized dendrimer molecules : an atomic force microscopy study

• Main Authors: Wiesler, U. M., Grim, P. C. M., Vosch, T., Berresheim, A. J., Müllen, K., Van Haesendonck, C., Vandamme, N., De Schryver, F. C., Zhang, Hua, Liu, Daojun, De Feyter, Steven
• Other Authors: School of Materials Science & Engineering
• Format: Article
• Language: English
• Published: 2012
• Subjects: DRNTU::Engineering::Materials
• Online Access: https://hdl.handle.net/10356/95392; http://hdl.handle.net/10220/8549
• Institution: Nanyang Technological University

Polyphenylene dendrimer molecules, G2Td(COOH)16, were ionized (G2 ions) and then adsorbed on a carboxylic acid (COOH) group terminated self-assembled monolayer (SAM) on a Au substrate through the linkage with Cu2+ ions. The individual G2 ions were observed by noncontact atomic force microscopy (NCAFM). The strong interaction between the G2 and Cu2+ ions, the latter of which are preadsorbed on the COOH SAM, led to a compression or deformation of the SAM and resulted in a decreased height of the G2 ions measured by NCAFM as compared to a theoretical model of the dendrimer molecules. The present method offers an approach to bind dendrimer molecules to a solid substrate and to study the nanoscale behavior of two kinds of thiol molecules in replaced and mixed SAMs.