摘要
The photothermal effect enhances the antibacterial activity by generating localized heat that disrupts microbial cells, leading to increased bacterial inactivation. The objective of this study was to develop and evaluate the antibacterial and photothermal applications of polydopamine-berberine nanoparticles (PDA-BBR-NPs), incorporating them into a sodium alginate matrix for food preservation. The self-assembled PDA-BBR-NPs were synthesized using a solution oxidation method and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and nanoparticle size analysis. The results demonstrated that PDA-BBR-NPs were uniform spheres with an average diameter of 177.1 nm. Drug loading and encapsulation efficiency tests showed that the optimal formulation had a drug loading capacity of 48.4% and an encapsulation efficiency of 84.7%. Antibacterial activity against E. coli and S. aureus was evaluated using the dilution coating plate method, showing an inhibition rate of over 98%. Photothermal testing under 808 nm near-infrared irradiation revealed a maximum photothermal conversion efficiency of 32.65%. To assess the practical application of the nanoparticles, they were incorporated into a sodium alginate-based coating for the preservation of Kyoho grapes. Key parameters such as weight loss, pH, titratable acidity, and soluble solids content were monitored over a 12-day storage period at room temperature. The PDA-BBR-NIR-treated group exhibited significantly reduced weight loss (6.08% lower than the control group) and a slower decrease in pH. The coating effectively inhibited microbial activity and extended the shelf life of the grapes by 3-6 days compared to the control group. These findings demonstrated the potential of PDA-BBR-NPs to enhance the preservation of fresh produce through their combined antibacterial and photothermal effects, offering a promising method for extending fruit shelf life.
危险品化学品经营许可证（带存储）