Bio-inspired multifunctional smooth lubricant-infused surface for residue-free, antimicrobial, and real-time freshness-monitoring food packaging.

Residual contamination, microbial growth, and the inability to monitor freshness in real-time are critical challenges in food packaging that affect safety and increase waste. Herein, we propose a novel multifunctional smooth lubricant-infused surface (SLIS) designed to address these issues. The SLIS was fabricated by infusing a porous carnauba wax coating with a functional water-in-oil (W/O) emulsion containing carvacrol (dissolved in oleic acid) and anthocyanin (dissolved in water). This SLIS exhibited excellent residue-free properties against common food liquids, and the addition of carvacrol effectively inhibited the adhesion and proliferation of foodborne pathogens (E. coli and S. aureus). Furthermore, leveraging the protective effect of the emulsion on anthocyanin, the SLIS generated a sensitive and visual color response to spoilage volatiles (ammonia and trimethylamine) released from perishable aquatic products (e.g., large yellow croaker and whiteleg shrimp), providing real-time, non-destructive freshness monitoring. This work demonstrated the feasibility of achieving multifunctional SLIS through W/O emulsion loading of functional ingredients, offering a promising strategy for advanced food packaging applications.