Fabrication of antifouling coating based on chitosan-melanin hybrid nanoparticles as sustainable and antimicrobial surface

In the current research, we have developed a very effective, completely biocompatible, cost-effective and ecofriendly method for antifouling purposes. Melanin nanoparticles and chitosan nanoparticles were isolated from sepia ink (Sepia Pharaonis) and Penaeus merguiensis and chitosan-melanin hybrid nanoparticles complex was synthesized, under reflux circumstances to enhance the anti-biofouling properties. The result of FTIR showed that a new band between chitosan and melanin nanoparticles was in the absorption range of 1633 cm−1. Moreover, TEM and FESEM analysis of chitosan-melanin hybrid nanoparticles indicated that nanoparticles are spherical. Laboratory biological assays that including antibacterial activities, antialgal activity as well as, zooplanktonic reactions in Artemia salina and barnacle Amphibalanus amphitrite to chitosan-melanin hybrid nanoparticles were evaluated. The MIC of chitosan-melanin hybrid nanoparticles was observed against E. coli (1.56 μg/mL) and S. aureus (0.871 μg/mL) and also the median inhibition concentration (IC50) value of exposed Isochrysis galbana to chitosan-melanin hybrid nanoparticles after 48 h was 0.176 mg/mL. The field immersion was evaluated in natural seawater, in different concentration (3, 2, 1 and 0.5 % wt) of chitosan-melanin hybrid nanoparticles, for 3 month. The most successful and effective results were observed for the panel with 3 wt% chitosan-melanin hybrid nanoparticles, which had lowest weight (28 g) of biofouling. According to the findings of this study, chitosan-melanin hybrid nanoparticles have ideal and good potential to antifouling properties.