Applied Microbiology and Biotechnology

, Volume 93, Issue 2, pp 743–751

Antibacterial activity and interaction mechanism of electrospun zinc-doped titania nanofibers

  • Touseef Amna
  • M. Shamshi Hassan
  • Nasser A. M. Barakat
  • Dipendra Raj Pandeya
  • Seong Tshool Hong
  • Myung-Seob Khil
  • Hak Yong Kim
Applied Microbial and Cell Physiology

DOI: 10.1007/s00253-011-3459-0

Cite this article as:
Amna, T., Hassan, M.S., Barakat, N.A.M. et al. Appl Microbiol Biotechnol (2012) 93: 743. doi:10.1007/s00253-011-3459-0

Abstract

In this study, a biological evaluation of the antimicrobial activity of Zn-doped titania nanofibers was carried out using Escherichia coli ATCC 52922 (Gram negative) and Staphylococcus aureus ATCC 29231 (Gram positive) as model organisms. The utilized Zn-doped titania nanofibers were prepared by the electrospinning of a sol–gel composed of zinc nitrate, titanium isopropoxide, and polyvinyl acetate; the obtained electrospun nanofibers were vacuum dried at 80°C and then calcined at 600°C. The physicochemical properties of the synthesized nanofibers were determined by X-ray diffraction pattern, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, electron probe microanalysis, thermogravimetry, and transmission electron microscopy (TEM). The antibacterial activity and the acting mechanism of Zn-doped titania nanofibers against bacteria were investigated by calculation of minimum inhibitory concentration and analyzing the morphology of the bacterial cells following the treatment with nanofibers solution. Our investigations reveal that the lowest concentration of Zn-doped titania nanofibers solution inhibiting the growth of S. aureus ATCC 29231 and E. coli ATCC 52922 strains is found to be 0.4 and 1.6 μg/ml, respectively. Furthermore, Bio-TEM analysis demonstrated that the exposure of the selected microbial strains to the nanofibers led to disruption of the cell membranes and leakage of the cytoplasm. In conclusion, the combined results suggested doping promotes antimicrobial effect; synthesized nanofibers possess a very large surface-to-volume ratio and may damage the structure of the bacterial cell membrane, as well as depress the activity of the membranous enzymes which cause bacteria to die in due course.

Keywords

Pathogenic bacteriaAntibacterial mechanismZn-doped titania nanofibersTransmission electron microscopy (TEM)X-ray diffraction (XRD)

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Touseef Amna
    • 1
  • M. Shamshi Hassan
    • 2
  • Nasser A. M. Barakat
    • 2
    • 3
  • Dipendra Raj Pandeya
    • 4
  • Seong Tshool Hong
    • 4
  • Myung-Seob Khil
    • 2
  • Hak Yong Kim
    • 2
  1. 1.Center for Healthcare Technology DevelopmentChonbuk National UniversityJeonjuRepublic of Korea
  2. 2.Organic Materials and Fiber Engineering DepartmentChonbuk National UniversityJeonjuRepublic of Korea
  3. 3.Chemical Engineering Department, Faculty of EngineeringEl-Minia UniversityEl-MiniaEgypt
  4. 4.Department of Microbiology and Immunology, Institute for Medical ScienceChonbuk National University Medical SchoolJeonjuRepublic of Korea