School of Chemical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk 38541, Republic of Korea.
School of Chemical Engineering, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk 38541, Republic of Korea.
Food Chem. 2021 Apr 16;342:128385. doi: 10.1016/j.foodchem.2020.128385. Epub 2020 Oct 15.
Graphene-based nanocomposites with superior antibacterial activity are highly sought after by the food packaging industries. Here, we report for the first time a method that utilizes soluble starch biopolymer as a functionalizing and reducing agent for the preparation of starch-reduced graphene oxide (SRGO), whereby polyiodide binds to the helical structures of amylose units of the starch (chromophore) to form a SRGO-polyiodide nanocomposite (SRGO-PI NC). UV-visible spectroscopy, X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and energy-dispersive spectroscopy confirmed the presence of polyiodide in SRGO. SRGO-PI NC exhibited good antibacterial activities against pathogenic Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) microbes with minimum inhibitory concentrations (MICs) and minimum bactericidal concentration (MBC) values (as determined by a broth-dilution method) of 2.5 and 5 mg/ml, respectively, for both E. coli and S. aureus. PrestoBlue viability assays showed half-maximal inhibitory concentration (IC) values of 0.45 and 0.41 mg/ml for E. coli and S. aureus, respectively. Time-kill kinetic and live/dead bacterial viability assays revealed the antimicrobial activities of SRGO-PI NC against both E. coli and S. aureus. The study provides new insights regarding the utilization of graphene-polyiodide NCs as high-efficacy antibacterial starch-based nanomaterials for food packaging applications.
具有优异抗菌活性的基于石墨烯的纳米复合材料受到食品包装行业的高度追捧。在这里，我们首次报道了一种利用可溶性淀粉生物聚合物作为功能化和还原剂来制备淀粉还原氧化石墨烯（SRGO）的方法，其中多碘化物与淀粉（生色团）的直链结构结合形成 SRGO-多碘化物纳米复合材料（SRGO-PI NC）。紫外-可见光谱、X 射线衍射、拉曼光谱、扫描电子显微镜和能谱分析证实了 SRGO 中多碘化物的存在。SRGO-PI NC 对致病性革兰氏阴性（大肠杆菌）和革兰氏阳性（金黄色葡萄球菌）微生物表现出良好的抗菌活性，最小抑菌浓度（MIC）和最小杀菌浓度（MBC）值（通过肉汤稀释法确定）分别为 2.5 和 5 mg/ml，对大肠杆菌和金黄色葡萄球菌均有效。PrestoBlue 活力测定显示，大肠杆菌和金黄色葡萄球菌的半最大抑制浓度（IC）值分别为 0.45 和 0.41 mg/ml。时间杀伤动力学和活菌/死菌活力测定显示了 SRGO-PI NC 对大肠杆菌和金黄色葡萄球菌的抗菌活性。该研究为利用石墨烯-多碘化物 NC 作为高效抗菌淀粉基纳米材料在食品包装应用中提供了新的见解。
