Mussel-Inspired, One-Step Thiol Functionalization of Solid Surfaces

Mussel-inspired surface chemistry, in which catechol derivatives play an important role, has garnered extensive research interest owing to material-independent surface coating capability and easy implementation to a wide range of applications. Generally, sequential reactions comprising catechol oxidation, intramolecular reaction of oxidized catechols with nucleophiles, and intermolecular assembly result in polymers that can adhere to many diverse surfaces. Although amines and thiols have similar reactivity toward oxidized catechols, most studies have been conducted with catechol and amine groups as essentials. Surface coating with catechol-thiol has not been investigated. In this study, we show that 4-(2-mercapto-ethyl)-benzene-1,2-diol (catechol-thiol) can serve as a surface coating agent in the presence of a strong oxidant. A wide range of materials are coated with catechol-thiol, and an additional grafting of the functional molecules onto the surface is also performed through well-established thiol chemistry, Michael addition, and thiol-ene reaction.