Design of γ-AlOOH, γ-MnOOH, and α-Mn2O3 nanorods as advanced antibacterial active agents

Dalton Trans. 2020 Jun 29;49(25):8601-8613. doi: 10.1039/d0dt01689f.

Abstract

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.

MeSH terms

  • Aluminum Hydroxide / chemical synthesis
  • Aluminum Hydroxide / chemistry
  • Aluminum Hydroxide / pharmacology*
  • Aluminum Oxide / chemical synthesis
  • Aluminum Oxide / chemistry
  • Aluminum Oxide / pharmacology*
  • Anti-Bacterial Agents / chemical synthesis
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Bacillus subtilis / drug effects
  • Bordetella pertussis / drug effects
  • Drug Design
  • Hydroxides / chemical synthesis
  • Hydroxides / chemistry
  • Hydroxides / pharmacology*
  • Manganese Compounds / chemical synthesis
  • Manganese Compounds / chemistry
  • Manganese Compounds / pharmacology*
  • Metal Nanoparticles / chemistry
  • Microbial Sensitivity Tests
  • Nanotubes / chemistry*
  • Oxides / chemical synthesis
  • Oxides / chemistry
  • Oxides / pharmacology*
  • Particle Size
  • Pseudomonas aeruginosa / drug effects
  • Silver / chemistry
  • Surface Properties

Substances

  • Anti-Bacterial Agents
  • Hydroxides
  • Manganese Compounds
  • Oxides
  • Silver
  • Aluminum Hydroxide
  • aluminum oxide hydroxide
  • manganese oxide
  • Aluminum Oxide