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Abstract As a result of frequent outbreaks occurring due to poor hygiene and improper sanitation of processing environments, there has been an increasing demand for the development of food-contact surface materials that intrinsically inhibit and reduce likelihood of potential microbial adherence and biofilm formation. Herein, we report the synergistic utilization of surface nanotexturing and chemical modifications with nonpolar functional groups on aluminum surfaces to produce coatings having bacterial super-repellant and mud anti-fouling characteristics. Using these coatings, the attachment of Salmonella Typhimurium LT2 and Listeria innocua as pathogen surrogates was reduced more than 99.0%, compared to the bare aluminum surfaces. In addition, the coating strongly resisted the adhesion of mud, showing a 10-fold reduction in the area of mud adhesion upon submerging in mud solution. Moreover, this method is both versatile and scalable, involving inert and biocompatible building blocks. Overall, this study contributes to the field of food safety through the design and development of novel coatings for achieving improved food safety and hygiene. Highlights • Biocompatible silica-based superhydrophobically-modified aluminum surfaces were developed. • Attachment of Salmonella Typhimurium LT2 and Listeria innocua was reduced by >99.0%. • Superhydrophobically-modified aluminum surfaces exhibited excellent mud-repelling activity. • Bacterial anti-adhesion properties are attributed to weak intermolecular interactions. • The proposed surface modification method can be applied to metal food-contact surfaces. [ABSTRACT FROM AUTHOR]

Foodborne illness outbreaks caused by bacterial pathogens may take place on a large scale and result in millions of hospitalizations and thousands of deaths every year throughout the world. One key strategy for dealing with this global issue is the design of smart surfaces and coatings which inhibit and reduce bacterial attachment. This can mitigate contamination and cross-contamination during farm-to-table food processing, promoting food safety, and hygiene. Herein, we reported a durable superhydrophobic coating on aluminum surfaces fabricated by sequential deposition of ultrahard nanodiamond, self-assembly of l-3,4-dihydroxyphenylalanine (l -dopamine), and chemical modification with an organoflurosilane. This coating achieved static, advancing, and receding water contact angles of 159.0 ± 2.5°,154.0 ± 2.4°; and 153.7 ± 1.7°, respectively, representing water super-repellency with a low overall root mean square (rms) roughness of 173.5 ± 69.6 nm. In comparison to the bare, unmodified aluminum, the coated aluminum surfaces prevented the attachment of 99.5% of applied Escherichia coli O157:H7 (E.coli O157:H7) and 99.0% of Staphylococcus aureus (S. aureus) cells. In addition, due to the presence of nanodiamond building blocks, the coated surfaces demonstrated a high mechanical resistance against scratching and endured at least 10,000 shearing/rubbing cycles with a nylon surface. Overall, we anticipate that implementation of this coating could improve safety and hygiene of food-contact surfaces that require harsher mechanical operational conditions. • Development of biocompatible nanodiamond-based superhydrophobic coating on aluminum surfaces. • Attachment of Escherichia coli O157:H7 and Staphylococcus aureus was reduced by >99.0%. • Superhydrophobic aluminum surfaces exhibited excellent mechanical resistance against polymer scratching. • Bacterial antiadhesion properties are based on the minimized contact area and weak intermolecular interactions. • The proposed superhydrophobic coating can be applied on metal food-contact surfaces. [ABSTRACT FROM AUTHOR]