Electrochemically Switchable Adhesion of a Catechol Functionalized Monolayer

Alexander Michael Imre, Hsiu-Wei Cheng, Markus Valtiner
The adhesion of marine mussels has peaked the interest of many in the scientific community because of their ability to firmly attach to a wide range of substrates in wet and saline conditions. Such environments are generally unfavorable for conventional synthetic adhesives. With the hope of developing better, potentially biocompatible adhesives a lot of work has gone into studying the mechanisms involved in mussel adhesion. The catechol functional group has been found to be crucial in the
more » ... rucial in the attachment process and a large number of studies using the surface force apparatus have looked into catechol mediated adhesion. In addition, the catechol group is also able to undergo a redox reaction and has been well studied using electrochemistry. Yet, so far, these two aspects of catechol chemistry have remained largely disconnected. This work aims to demonstrate a way to connect these two approaches. A catechol functionalized self assembled monolayer was produced and then charac- terized using cyclic voltammetry. It was then put up against different surfaces in the electrochemical surface force apparatus where a potential dependent, switch- able adhesion was measured against mica. Furthermore, adhesion was strongly dependent on the ionic strength of the environment. This observation may help understand which mechanisms mussels use in nature to form adhesive bonds. Altogether, the combination of a functionalized monolayer and the electrochem- ical surface force apparatus provides a promising sample system for future study of the interfacial behavior of catechols and other electrochemically active function- alities. As a side product of this work, a new design for a thin film electrode was developed and improvements were made to an electrochemical cell setup, which will potentially benefit future work in catechol electrochemistry and other research areas.
doi:10.34726/hss.2021.85300 fatcat:td44k2uh7bd77ocikhmzv5vnze