Carbon Dots as Multifunctional Nanofillers in Sustainable Food Packaging: A Comprehensive Review.

Food packaging systems play a critical role in reducing resource wastage, extending shelf-life, and enhancing supply chain sustainability. Carbon dots (CDs) have emerged as promising nanofillers for sustainable active and smart packaging due to their exceptional optical properties, biocompatibility, and antimicrobial activity. This review synthesizes recent advances in CD-based food packaging technologies, focusing on their multifunctional applications and performance enhancements. We systematically analyze how CDs improve packaging materials' mechanical strength, gas barrier properties, and functional performance (antioxidant, antimicrobial, and smart sensing capabilities). Current research demonstrates CDs' ability to enable intelligent functions such as pH responsiveness and freshness monitoring while maintaining excellent biocompatibility. However, challenges remain in scaling up production, long-term toxicological evaluation, and matrix compatibility. Future research directions should address these limitations while exploring the full potential of CD-based multifunctional films as sustainable alternatives for next-generation food packaging systems.