US Researchers Develop Non-toxic & Eco-friendly Antifouling Paint for Ships: An Enzyme Coating for Direct Surface Application

Antifouling coatings, which slow the growth of organisms, typically rely on the toxicity of copper and small-molecule additives that act as pesticides in the water near a ship’s hull. US Researchers have identified active proteins, or enzymes, as potential nontoxic antifouling agents

“Many marine animals do not want to be covered in biofouling and have developed enzymes to protect themselves,” said project lead Reid Messersmith, a molecular engineer in APL’s Research and Exploratory Development Department (REDD). “Taking inspiration from animals, we developed an enzyme coating that could be applied directly to surfaces.”

Researchers identified an effective “linker”, an agent capable of bonding an enzyme to a synthetic compound, and developed an enzyme-based polymer coating with an ortho-phthaldialdehyde (oPA)-based linker, which is capable of bonding enzymes onto surfaces, and doing so rapidly, taking less than five minutes to form a layer of material. The oPA-based linker maintained activity for extended periods of time in experiments, compared to no linker and a commercially available linker. For effectiveness and compatibility with the coating system, they settled on xylanase, a naturally occurring enzyme produced by fungi, bacteria, marine algae, and many other organisms, often used in commercial baking, and a mixture of lysing complex enzymes, a molecule extracted from a fungus.

Click Chemistry: The team used a method called click chemistry, which enabled them to attach the coating without any catalyst or heat. After two months submerged in artificial seawater, the xylanase and lysing complex coatings proved highly active, demonstrating the material’s longevity and potential for eco-friendly antifouling. Remarkably, the approach was successful on the first try.

https://www.jhuapl.edu/news/news-releases/230413b-antifouling-paintable-proteins