A marine makeover

Nature Nanotech.http://doi.org/h23 (2012)

The build-up of marine microorganisms on surfaces in contact with seawater is not only a problem for the object itself, for example a boat's hull, but there are also knock-on environmental effects. Materials that prevent the adhesion of, but are not toxic to, marine microorganisms are therefore of great commercial interest. Now, Wolfgang Tremel and colleagues report that surfaces coated with vanadium pentoxide (V₂O₅) nanowires show strong antibacterial activity, to both Gram-negative and Gram-positive bacteria, and prevent marine biofouling. The nanowires are less toxic than other chemical compounds already approved for use by the International Maritime Organization. The mechanism behind the biofouling properties of the V₂O₅ nanowires is similar to naturally occurring vanadium haloperoxidases—enzymes that prevent biofilm formation on seaweed. The antibacterial activity of the nanowires is preserved when formulated in paint, and a stainless steel plate covered with the nanowires remains without any biofouling when placed on a boat hull in seawater for 60 days, whereas control plates with commercially available paint become covered with marine life.