Nanofunctionalized superhydrophobic antifouling coatings for environmental sensor applications-advancing deployment with answers from nature

In this work, a novel preparation for superhydrophobic nanofunctionalized silver and gold, copper-coated substrates as potential antifouling coatings for environmental monitoring devices are fabricated. The superhydrophobic coating is topographically similar to the design of the Lotus leaf (Nelumbo necifera) and was synthesized by creating an electroless galvanic reaction between copper and the metal salt. In doing so, a nano- and micro-topographical structure was created on the surface of a copper substrate which can be rendered superhydrophobic through the addition of a self-assembled monolayer (SAM) of CF3(CF2)7CH2CH2SH. The work investigates whether the hydrophobicity of such materials affects micro-organism attachment and subsequent biofouling. The materials are deployed in a marine environment in Dublin, Ireland for a 6 week study to determine the overall antifouling capacity. The materials are analyzed for biomass, slime (glycocalyx) production and more specifically protein and carbohydrate adsorption all of which are attributed to the inherent makeup of biofilm and exopolymeric substances (EPS) which are secreted by micro-organisms during the biofouling process. This work highlights the dominance of combinational antifouling approaches rather than single tactics for such a complex problem and one that plagues multiple research areas. This novel approach in developing a new antifouling material for sensors, and indeed, any aquatic platform has shown excellent results throughout. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.