Bioinspired Serotonin Antagonists as Universal Antifouling Agents against Complex Marine Biofouling

Marine fouling is a burden to the environment and economy.
The
diversity of marine fouling organisms has led to the development of
poisonous antifouling agents. Nevertheless, toxic antifouling agents
pose ecological challenges because they accumulate in the food chain;
consequently, a new environmentally sustainable solution that is nontoxic
to marine organisms yet universally effective against complex biofouling
species is needed. Here, we replace persistent biocides with transient
antagonists as key antifouling materials, with serotonin-receptor
antagonists used to control marine fouling because mussels and barnacles
rely on the serotonin receptor to sense surfaces. Chlorpromazine exhibits
the best antifouling capability among the antagonists tested, preventing
fouling by hard fouling organisms, such as mussels and barnacles,
and by soft fouling organisms, such as algae, exemplified by the series
of antifouling-coating efficacy trials, including a 12-week dynamic
oceanic ship test and an 18-week static ocean environment test. Serotonin
receptor antagonists inhibit the formation of biofilms (microfouling),
thereby suppressing underlying mechanisms that lead to macrofouling.
The antagonists are metabolized and excreted rather than accumulating
in organisms; an antagonist-based antifouling strategy is a sustainable
approach for controlling marine fouling for both static and dynamic
ocean environments.