Covalent layer-by-layer fabrication of single polyelectrolyte multilayers with embedded silver nanoparticles for antibacterial applications.

• Main Author: Toh, Joel Nathaniel Zhi Hao.
• Other Authors: Chan Vincent
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Chemical engineering::Biotechnological production
• Online Access: http://hdl.handle.net/10356/39028
• Institution: Nanyang Technological University

Polyelectrolyte multilayer (PEM) films are typically fabricated by the layer-by- layer (LBL) deposition of a pair of oppositely charged polyelectrolytes on a substrate via electrostatic attractions. Despite the promising potential of PEMs in biomaterials, the lack of long-term stability of such PEMs in face of changes in physiological conditions limits its application as an effective antibacterial coating in medical devices.In this study, a PEM containing only a single polyelectrolyte, polyethyleneimine (PEI), was constructed by covalent LBL deposition with the use of terephthalaldehyde (TA) as the chemical cross-linker. Firstly, the specific buildup of TA and PEI layers during covalent LBL assembly was validated by UV-Vis absorbance spectroscopy and atomic force microscopy. Next, silver (Ag) nanoparticles were incorporated into TA/PEI multilayers via the in situ reduction of Ag+ ions with the prior adsorption of sodium borohydride (NaBH4) into the PEM.