Rapid coordination-driven Fe-DNA nanonetwork loaded with curcumin for fruit preservation

Every year, a significant amount of fruit and vegetable spoilage caused by microbial contamination leads to substantial food waste and economic losses in the agricultural and food sectors. There is an urgent need to develop highly efficient and safe multifunctional preservation materials. Curcumin (Cur) is known for its excellent antioxidant and antibacterial properties; however, its poor water solubility and low bioavailability severely limit its practical applications. In this study, we synthesized highly stable and water-dispersible metal-biomolecule network nanoparticles by self-assembly of ferrous ions (Fe²⁺) with DNA in an aqueous solution at room temperature. Furthermore, by leveraging the strong coordination interaction between Fe and Cur, we prepared Cur-modified nanoparticles (Fe-DNA-Cur) with dual antioxidant and antibacterial functions. Fe-DNA-Cur not only preserves the biological activity of curcumin, but also effectively addresses its inherent poor water solubility. After further compounding with chitosan (CS), the as-prepared Fe-DNA-Cur@CS composite demonstrates breakthrough antimicrobial performance, thereby providing an innovative solution for developing novel, highly effective and safe fruit/vegetable preservatives. When used as a sustainable food packaging coating for perishable fruits at room temperature, the Fe-DNA-Cur@CS coating can reduce dehydration, prevent nutrient loss, inhibit microbial growth, increase nutraceutical value, maintain strawberry quality, and extend shelf life during storage. This study demonstrates the potential of Fe-DNA-Cur@CS as a multifunctional coating material to reduce food waste and agricultural economic losses caused by microbial contamination.