Cold-Adaptive Haloperoxidase-Mimicking Copper-Dipeptide Hybrid Nanoparticle for Antibiofilm Formation

Marine biofouling causes significant economic and environmental challenges. Inspired by marine algae's natural defense through haloperoxidase (HPO) secretion, researchers have developed HPO mimics as effective antifouling agents. However, their application in marine environments is limited by the scarcity of HPO mimics, their preference for acidic conditions, and the complexity of their synthesis. The study introduces a novel HPO mimic, HH-Cu, synthesized through a one-step precipitation reaction by mixing copper ions and dipeptides in phosphate-buffered saline. HH-Cu exhibits exceptional stability under extreme conditions, including varying pH levels, high temperatures, various interfering substances, and long-term storage. It maintains 90% of its activity even after ten uses. Notably, it exhibits high activity under neutral and alkaline conditions, with optimal HPO-like activity at pH 8, which coincides with the pH range of seawater (pH 7.8–8.2). Leveraging its strong HPO-like activity, HH-Cu exhibits significant antibacterial effects and biofilm inhibition. Importantly, HH-Cu is wide-temperature adaptive (0-50 °C), displaying substantial HPO-like activity and antibacterial properties even at temperatures as low as 0 °C. This is the first example of a HPO mimic with low-temperature adaptability. The study not only broadens the range of HPO mimics but also highlights the potential of HH-Cu in biofouling treatment.