School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, P. R. China.
Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101 Qingdao, P.R. China and University of Chinese Academy of Sciences, Beijing 100039, China and Processes Development Department, EPRI, Nasr City 11727, Cairo, Egypt.
Dalton Trans. 2020 Jun 29;49(25):8601-8613. doi: 10.1039/d0dt01689f.
In the current study, γ-AlOOH, γ-MnOOH, and α-Mn2O3 nanorods (NRs) were easily synthesized and applied as advanced antibacterial materials. γ-AlOOH NRs with 20 nm width, [100] crystal plane, and 200 nm length were fabricated through a surfactant-directed solvothermal method. γ-MnOOH NRs with 20 nm width, [101] crystal direction and 500 nm length were fabricated through a hydrothermal method. The prepared γ-MnOOH NRs were calcinated (for 5 h) at 700 °C to produce α-Mn2O3 NRs with 20 nm average width and increased surface area. The NRs' structures were confirmed through FT-IR, XRD, XPS, FESEM, and FETEM. The antibacterial activity of the NRs was studied against different Gram-negative and Gram-positive bacterial strains and yeast. The three NRs exhibited antibacterial activity against all of the used strains. Biological studies indicated that the NRs' antimicrobial activity increased in the order of γ-MnOOH < γ-AlOOH < α-Mn2O3 NRs. The α-Mn2O3 NRs exhibited the lowest MIC value (39 μg mL-1) against B. subtilis, B. pertussis, and P. aeruginosa. The prepared NRs exhibited a higher antimicrobial potential toward Gram-positive bacteria than Gram-negative bacteria. The higher antimicrobial activity of the α-Mn2O3 NRs is highlighted based on their larger surface area and smaller diameter. Consequently, uniform NR architectures, single crystallinity, small nanoscale diameters, and more highly exposed [110] Mn-polar surfaces outwards are promising structures for α-Mn2O3 antibacterial agents. These NRs adhered firmly to the bacterial cells causing cell wrapping and morphology disruption, and microbial death. The designed NRs provide a great platform for microbial growth inhibition.
在本研究中,γ-AlOOH、γ-MnOOH 和 α-Mn2O3 纳米棒(NRs)被轻易合成并应用为先进的抗菌材料。通过表面活性剂导向的溶剂热法制备了具有 20nm 宽度、[100] 晶面和 200nm 长度的 γ-AlOOH NRs。通过水热法制备了具有 20nm 宽度、[101] 晶向和 500nm 长度的 γ-MnOOH NRs。所制备的 γ-MnOOH NRs 在 700°C 下煅烧(5h)以生成具有 20nm 平均宽度和增加的表面积的 α-Mn2O3 NRs。通过 FT-IR、XRD、XPS、FESEM 和 FETEM 确认 NRs 的结构。研究了 NRs 对不同革兰氏阴性和革兰氏阳性细菌菌株和酵母的抗菌活性。三种 NRs 对所有使用的菌株均表现出抗菌活性。生物学研究表明,NRs 的抗菌活性按 γ-MnOOH < γ-AlOOH < α-Mn2O3 NRs 的顺序增加。α-Mn2O3 NRs 对枯草芽孢杆菌、百日咳博德特氏菌和铜绿假单胞菌的最低 MIC 值(39μg mL-1)。所制备的 NRs 对革兰氏阳性菌的抗菌潜力高于革兰氏阴性菌。α-Mn2O3 NRs 具有较高的抗菌活性,这是基于其较大的表面积和较小的直径。因此,具有均匀 NR 结构、单晶性、较小的纳米级直径和更多向外暴露的[110]Mn 极性表面的 NR 结构有望成为 α-Mn2O3 抗菌剂的理想结构。这些 NRs 牢固地附着在细菌细胞上,导致细胞包裹和形态破坏以及微生物死亡。设计的 NRs 为抑制微生物生长提供了一个很好的平台。