PDA@CaCO3/SiO2复合抗菌剂的制备、表征及其在水果贮藏中的应用

Preparation、characterization and application of PDA@CaCO3/SiO2 compound antibacterial agent in fruit storage

摘要:

本文在温和条件下成功制备出PDA@CaCO3/SiO2复合纳米光敏剂。并用X射线衍射、傅里叶变换红外光谱、场发射扫描电子显微镜、Brunauer- Emmett-Teller对样品进行一系列表征。对比了PDA@CaCO3/SiO2复合纳米光敏剂和CaCO3/SiO2对大肠杆菌（Escherichia coli，E. coli）的抑菌效果。实验结果表明，PDA@CaCO3/SiO2复合抗菌剂具备卓越的光热转换性能，并在8 min内实现温度快速上升至47.5 ℃。经1.2 W/cm2功率的近红外光照8 min后，CaCO3@SiO2和PDA@CaCO3/SiO2对大肠杆菌的杀菌率分别达到了90.40%和97.34%。经过3次重复实验后，PDA@CaCO3/SiO2复合抗菌剂抑菌率仍可达90%以上。含有PDA@CaCO3/SiO2复合抗菌剂的保鲜膜抑菌试验表明，PDA@CaCO3/SiO2复合抗菌剂可以有效抑制水果表面的大肠杆菌，水果经贮藏4天后，抑菌率仍为97%。PDA@CaCO3/SiO2复合抗菌剂生物相容性好。该研究证明了PDA@CaCO3/SiO2复合抗菌剂对大肠杆菌的抑菌性能，为水果中可降解光热抗菌剂的研发提供理论支持。

Abstract:

In this work, PDA@CaCO3/SiO2 composite nano photosensitizer was successfully prepared under mild conditions. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and Brunauer Emmett Teller analysis, etc. The bacteriostatic effects of PDA@CaCO3/SiO2 composite nano photosensitizer and CaCO3/SiO2 on Escherichia coli (E. coli) were compared. The experimental results showed that PDA@CaCO3/SiO2 composite antibacterial agent had excellent photothermal conversion performance, and the temperature rapidly rised to 47.5 ℃ within 8 min. After 8 min of NIR irradiation with 1.2 W/cm2 power, the bactericidal effects of CaCO3@SiO2 and PDA@CaCO3/SiO2 on E. coli reached 90.40% and 97.34% respectively. The antibacterial rate of PDA@CaCO3/SiO2 compound antibacterial agent could still reach more than 90% after three repeated experiments. The antibacterial test of plastic wrap containing PDA@CaCO3/SiO2 showed that PDA@CaCO3/SiO2 could effectively inhibit Escherichia coli on the surface of fruits, and the antibacterial rate was 97% after 4 days of storage. PDA@CaCO3/SiO2 composite antibacterial agent has good biocompatibility. This study demonstrated the antibacterial performance of PDA@CaCO3/SiO2 composite antibacterial agent on Escherichia coli, and provided theoretical support for the research and development of biodegradable photothermal antibacterial agents in fruits.