Scalable and Rechargeable Antimicrobial Coating for Food Safety Applications.

Environmental surfaces are common avenues for microbial contamination and transmission in food-processing establishments. We recently synthesized a polymer that combines both N-halamine and dopamine functional groups to form a novel antimicrobial coating material. A series of chemical (titration) and biological ("sandwich" and anti-inhabitation) tests were designed to prove the stability and functionality of as-developed coating material. Halamine-dopamine polymer-coated stainless-steel surface inactivated 6 log CFU of both Staphylococcus aureus and Escherichia coli O157:H7 under experimental detection limit within 10 min of contact time. After three "discharge-recharge" cycles, the surface maintained the same antimicrobial effectiveness; 60% of the surface chlorine remained after 10 "discharge-recharge" cycles. In addition, the coating thickness and chlorine content could be further tuned through adjusting the formulation of the coating. We also demonstrated that this coating material could be easily scaled up to apply on real food equipment parts through a spray-coating method. Thus our polymer material has great potential to produce a high-performance, low-cost, and easy-to-apply coating on food-associated environmental surfaces for food safety preventive-control applications.