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载银氧化壳聚糖复合物的制备及其抑菌性能的研究
Preparation of silver-loaded oxidized chitosan complex and study on its antibacterial properties
【摘要】 以壳聚糖(CS)为原料,采用漆酶/2,2,6,6-四甲基哌啶-1-氧自由基(TEMPO)体系选择性氧化分子上C6伯羟基形成羧基,得到氧化壳聚糖(C-COS),将C-COS与硝酸银反应制得载银氧化壳聚糖复合物(C-COS-Ag)。采用傅里叶红外光谱(FT-IR)、电导滴定、X射线光电子能谱(XPS)对产物进行表征,并以4种不同细菌作为抑菌模板,利用紫外分光光度计对C-COS-Ag抑菌条件进行优化,最后使用扫描电镜(SEM)观察C-COS-Ag加入前后细菌的形貌变化。结果表明,氧化壳聚糖的羧基含量为1.42%,C-COS-Ag中Ag+结合方式以[Ag(NH3)2]OH和Ag2O(一部分为—COOAg;另一部分为Ag2O)两种形式存在,且存在比例为6∶4。C-COS-Ag的最佳抑菌条件为1 h、26℃,且抑菌圈直径>30 mm,大肠杆菌的最小抑菌浓度(MIC)为7.5μg/mL,金黄色葡萄球菌、沙门氏菌、枯草芽孢杆菌的MIC均为10μg/mL。C-COS-Ag的添加能够使细菌的细胞壁受损影响细菌的繁殖生长,最终起到较好的抑菌作用。
【Abstract】 Chitosan(CS) was used as raw material to oxidize its C6 primary hydroxyl group to carboxyl group by laccase/2,2,6,6-tetramethylpiperidine-1-oxyl radical(TEMPO) system to obtain oxidized chitosan(C-COS), and then reacted with C-COS and silver nitrate to obtain oxidized chitosan-Ag+ complex(C-COS-Ag). Fourier transform infrared spectroscopy(FT-IR), conductometric titration and X-ray photoelectron spectroscopy(XPS) were used to characterize four different bacteria as antibacterial templates, and UV spectrophotometer was used to optimized C-COS-Ag antibacterial conditions. The morphology of the bacteria before and after the addition of C-COS-Ag was observed by scanning electron microscopy(SEM). The results showed that when CS had a carboxyl group content of 1.42%, Ag+ existed in C-COS-Ag were [Ag(NH3)2]OH and Ag2O( one part was —COOAg and the other part was Ag2O) two forms. The optimal antibacterial condition of C-COS-Ag was 1 h and 26 ℃. The diameter of the inhibition zone was greater than 30 mm, and the minimum inhibitory concentration of Escherichia coli was 7.5 μg/mL. The minimum inhibitory concentration of staphylococcus aureus, salmonella and bacillus subtilis was 10 μg/mL. And the cell wall of the bacteria added with C-COS-Ag was damaged, which seriously affected the growth of bacteria.
【Key words】 laccase/TEMPO; chitosan; silver ion; covalent bond; antibacterial;
- 【文献出处】 功能材料 ,Journal of Functional Materials , 编辑部邮箱 ,2019年12期
- 【分类号】TB34
- 【被引频次】4
- 【下载频次】298