物理化学学报2023，Vol.39Issue(12)：155-167,13.DOI:10.3866/PKU.WHXB202212039
可见光激发的BiOl/ZnO纳米复合抗菌剂制备及其抗菌活性与机制
Performance Improvement and Antibacterial Mechanism of BiOl/ZnO Nanocomposites as Antibacterial Agent under Visible Light
摘要
Abstract
Bacterial infections cause various serious diseases including tuberculosis,meningitis,and cellulitis.Moreover,there is an increase in the number of drug-resistant bacterial strains,which has caused a global health issue.Thus,it is highly essential to develop more effective antibacterial agents.Currently,zinc oxide(ZnO)is commonly used as an inorganic antibacterial agent,but with a notable limit in efficiency.In this work,to improve ZnO antibacterial activity under visible light,bismuth oxyiodide(BiOl)with a narrow bandgap of 1.8 eV was used as a suitable refinement to ZnO.Four different BiOl/ZnO nanocomposites were designed and synthesized via a simple mechanical stirring method in an atmospheric environment;these were denoted as BiOl/ZnO-2.5％,BiOl/ZnO-5％,BiOl/ZnO-10％,and BiOl/ZnO-20％.The successful synthesis of the BiOl/ZnO nanocomposites was verified through X-ray powder diffraction,energy-dispersive X-ray analysis,scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).A unique BiOl/ZnO heterojunction was also observed for the nanocomposites through high-resolution TEM,XPS,and selected area electron diffraction.Ultraviolet-visible diffuse reflectance spectroscopy revealed that all four BiOl/ZnO nanocomposites exhibited improved visible light absorption and possessed narrower bandgaps than the ZnO nanoparticles(nano-ZnO).Furthermore,the antibacterial activities of all BiOl/ZnO nanocomposites were investigated under visible light against both gram-positive and gram-negative bacteria strains.The results indicated a significant improvement in the antibacterial activities of BiOl/ZnO-10％and BiOl/ZnO-20％against both Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).Strong light exposure was found to be attributable to an increase in the antibacterial activity against S.aureus.In addition,the antibacterial mechanistic investigation was conducted upon visible light activation.The SEM images showed completely broken bacterial cell walls for both bacteria strains after treatment with the BiOl/ZnO nanocomposites.Hydroxyl radicals(·OH),which are strong reactive oxygen species,generated by the BiOl/ZnO nanocomposites under visible light,were also trapped by 5,5-dimethyl-1-pyrroline-N-oxide.Furthermore,zeta potential analysis revealed the presence of more positively charged BiOl/ZnO nanocomposite surfaces than the surfaces of nano-ZnO.The metal ions released from the BiOl/ZnO nanocomposites under visible light were also studied through inductively coupled plasma mass spectrometry.Based on the above results,BiOl/ZnO nanocomposites were found to exhibit antibacterial mechanism similar to that of nano-ZnO.In the dark,E.coli growth was only inhibited by Zn2+released from both BiOl/ZnO nanocomposites and pure nano-ZnO.After visible light activation,·OH generated from the BiOl/ZnO nanocomposites mainly contributed to the bacterial cell death of both E.coli and S.aureus.This study proposes an effective strategy to enhance the antibacterial activity of nano-ZnO under visible light upon the formation of nanocomposites with BiOl.Besides,this study indicates that the ZnO-based nanocomposites can be used as a more effective antibacterial agent in clinical applications.关键词
BiOl/ZnO纳米复合材料/光催化/抗菌活性/可见光激发/活性氧Key words
BiOl/ZnO nanocomposites/Photocatalysis/Antibacterial activity/Visible light activation/Reactive oxygen species分类
化学引用本文复制引用
孔菁,张金贵,张素芬,奚菊群,沈明..可见光激发的BiOl/ZnO纳米复合抗菌剂制备及其抗菌活性与机制[J].物理化学学报,2023,39(12):155-167,13.基金项目
The project was supported by the National Natural Science Foundation of China(21673201),the Yangzhou Guangling District Science and Technology Plan Industry Foresight and Key Common Technology Key Project(GL202206),the Top-notch Academic Programs Project of Jiangsu Higher Education Institutions,China(TAPP),and the Priority Academic Program Development of Jiangsu Higher Education Institutions,China.国家自然科学基金(21673201),扬州市广陵区科技计划产业前瞻性与共性关键技术重点项目(GL202206),江苏高校品牌专业建设工程项目和江苏高校优势学科建设工程项目资助 （21673201）
