||Dopamine solution will conduct autoxidation and self-polymerization to form polydopamine particles in alkaline tris-(hydroxymethyl)aminomethane (Tris) buffer solution. At the same time, the ploydopamine deposition onto various substrates via|
covalent bond or non-covalent bond such as hydrogen bond, electrostatic interaction, π-π interaction, van der waal interaction. In this study, we used atomically flat mica to investigate the growth mode and the growth mechanism of polydopamine by atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), and contact angle measurment. On the other hand, we also used polydopamine-modified AFM tip to
detect the interaction with various substrates and designed surface patterning on polydimethylsiloxane (PDMS). The results show that the monolayer of polydopamine film is completed within 300 sec and the roughness had significantly changed compared with bare mica. The polydopamine-modified AFM tip had the strongest interaction with
Highly Oriented Pyrolytic Graphite (HOPG) due to the strong π-π interaction between the aromatic rings structure on polydopamine and the planar structure of sp2 orbital on HOPG. Finally, the surface patterning on PDMS by polydopamine successfully modified Au nanoparticles and Ag nanoparticles on specific area.