Speaker: Associated Professor Tomohiro Hayashi, Tokyo Institute of Technology, Japan

Title: Mechanism underlying anti-biofouling: behavior of molecules at bio interfaces

Abstract: Although surfaces rejecting adsorption of biomolecules and adhesion of cells and microorganisms (anti-fouling surfaces) are highly demanded, designs of these surfaces still involve difficulties because of the lack of understanding of the underlying mechanism. We first discuss the mechanism underlying the bio inertness of oligo (ethylene glycol)-, zwitterionic-, DNA, and peptide-terminated self-assembled monolayers (SAMs) by investigating the interfacial behavior of water molecules by surface force and surface-sensitive vibrational spectroscopic techniques. Our surface force measurements evaluating the interaction between SAMs in a physiological condition revealed that all investigated bioinert SAMs exhibited water-induced repulsion. In contrast, bio adhering SAMs do not show repulsion. Surface-enhanced infrared absorption spectroscopy unveiled the characteristic hydrogen bonding state of water molecules near the nonfouling monolayers. These results exhibit that interfacial water plays the role of a physical barrier to prevent bioadhesion.