等离子体改性壳聚糖材料的分子结构变化及其对致泻大肠杆菌O78的抗菌性能研究

Study on the Molecular Structure Change and Antibacterial Properties to Escherichia Coli O78 of Plasma Modified Chitosan Materials

为避免有害食源性微生物所带来的影响,利用等离子体技术,在氮气氛围下对壳聚糖材料表面进行改性,并通过衰减全反射傅立叶红外光谱、X射线光电子能谱等对材料表面的分子结构变化进行表征。同时,以致泻大肠杆菌O78为测试菌,探讨改性壳聚糖材料的抗菌性能。实验结果显示,等离子体改性过程中带电粒子在壳聚糖材料表面碰撞,使得材料表面–NH_(2)的比例增加。而–NH;基团可发生质子化生成–NH_(3)^(+),进而与大肠杆菌质膜结构中带负电荷的脂蛋白和脂多糖发生静电相互作用,改变其细胞膜的通透性,最终导致大肠杆菌死亡。而通过改变等离体子作用时间以及壳聚糖材料分子质量,可调控改性壳聚糖材料表面-NH_(2)的比例,最终影响材料的抗菌性能。该结果可为等离子体改性技术及壳聚糖基抗菌材料定向设计提供一定的参考。

In order to avoid the impact of harmful foodborne microorganisms,with plasma technology in the nitrogen atmosphere,chitosan was modified and characterized in this study.At the same time,the antibacterial properties of modified chitosan materials were researched.The results showed that the surface of chitosan-based materials was collided by the charged particles in the plasma.The percentage of–NH_(2) on the material surface was increased,which would generate–NH_(3)^(+) and connect lipoprotein and lipopolysaccharide on the membrane structure of Escherichia coli O78 by electrostatic interactions.This changed the permeability of its cell membrane and eventually caused the death of Escherichia coli.With different modified time and molecular weight of chitosan,the proportion of surface–NH_(2) of modified chitosan material can be regulated and ultimately affect the antibacterial properties of the material.The research in this paper can provide some reference for plasma modified technology and modification of chitosan-based antibacterial materials.