DOI: 10.1002/adem.201180037 Nanofunctionalized Superhydrophobic Antifouling Coatings for Environmental Sensor Applications----Advancing Deployment with Answers from Nature** By James Chapman and Fiona Regan* 1. Introduction Biofouling and biofilms exist as an impossible limiting factor to be overcome in ocean, marine, and freshwater in situ monitoring. Many potential solutions to this ‘‘age-old’’ problem have been introduced, [1–5] none of which seem to exhibit any plausible solution. Recently, marine monitoring took a new approach looking to obtain data in real-time, constantly and online. [6] These types of systems are often accompanied by sophisticated sensor equipment, telemetry units, and sensor sondes. The sensors themselves (all encompassed with housing and support structures) can often undergo intense fouling. The aim is to achieve long-term deployment times with good quality data measurements without the need for expensive cleaning regimes for the user i.e., reducing the cost of ownership for its owner. When a substrate is immersed into an aquatic medium it rapidly becomes colonized in a process where biofilms and subsequent biofouling accumulate, a process which is still not fully understood. [7] There are generally three stages of the biofouling process (i) the adsorption of organic and inorganic particulate matter, (ii) the colonization of micro-organisms and primary fouling organisms to the surface of the substrate, and (iii) the attachment and growth of higher fouling organisms known commonly as macrofoulers. The presence of fouling causes a range of deleterious effects for anyone faced tackling the problem, which can be financially testing. Generally the initial biofouling stage is stochastic and the attachment of micro-organisms held fast in the biofilm matrix is irreversible. Permanency occurs when exopolymeric RESEARCH ARTICLE [*] Dr. J. Chapman, Prof. F. Regan Marine & Environmental Sensing Technology Hub (MESTECH), National Centre for Sensor Research, School of Chemical Sciences, Dublin City University, Glasnevin, Dublin, (Ireland) E-mail: fiona.regan@dcu.ie [**] This work was supported by The QUESTOR Centre, Belfast, UK. 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 CF 3 (CF 2 )7CH 2 CH 2 SH. 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 combina- tional 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. ADVANCED ENGINEERING MATERIALS 2012, 14, No. 4 ß 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim wileyonlinelibrary.com B175