A liquid-like coating suppresses marine biofouling by interfering with surface motility of fouling organisms

Marine biofouling presents substantial economic and ecological challenges to maritime operations and the broader marine industry, highlighting the urgent need for effective antifouling technologies. In this study, we present a robust and straightforward strategy to fabricate liquid-like antifouling coatings (CAP–PMHS) by grafting natural capsaicin (CAP) onto the surface of poly(methylhydrosiloxane) (PMHS) through a one-step hydrosilylation reaction. The resulting eco-friendly coating significantly reduces bacterial adhesion by 96.3 ± 0.4% within 10 min. Mechanistically, the CAP–PMHS surface inhibits the initial adhesion and biofilm formation of Pseudomonas aeruginosa (microfouling organism) by disrupting bacterial chemosensory system and associated metabolic pathways. Furthermore, CAP–PMHS markedly suppresses the sensory responses of Crassostrea gigas (macrofouling organism) by targeting the sensory organs (foot region). Specifically, it effectively inhibits larval settlement by interfering with the chemosensitive transient receptor potential melastatin subfamily member 8 (TRPM8) channel, which is highly expressed in foot tissues of pediveligers. This simple yet effective design strategy, combined with molecular-level insights into sensing and adhesion mechanisms of fouling organisms, opens new pathways for developing non-lethal multifunctional antifouling materials with cross-species applicability. It further establishes a theoretical foundation for antifouling through bio-behavior modulation, enabling sustainable applications in marine antifouling, drag reduction, and biomedical engineering.