Antibacterial effect, structural characterization, and some applications of silver chiral nano-flower sculptured thin films

Abstract

Silver chiral nano-flowers with 3-, 4-, and 5-fold symmetry were produced using oblique angle deposition method in conjunction with the rotation of sample holder with different speeds at different sectors of each revolution. X-ray diffraction, atomic force microscopy, and scanning electron microscopy were employed to obtain the nanostructure and morphology of the films. Their antibacterial, electrical, and hydrophobic properties were investigated. Antibacterial properties were investigated against a range of microorganisms including Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 25923, and Candida albicans PTCC 5027. Electrical conductivity of these films relative to that of bulk sample is reduced by a factor of about 10 3 due to porosity, surface roughness, and anisotropic structure of these films. Hydrophobicity results show dependence on the symmetry of these chiral nano-flowers.

Chiral and Luminescent TiO2 Nanoparticles

“…The major interest to these nanomaterials is driven by the role of chirality being one of the key factors in molecular recognition. Chiral nanomaterials are expected to find applications in enantiomeric separation, antibacterial surfaces, asymmetric catalysis, cellular imaging, and chiroptical applications …”

Detection of overtone and combined peaks using Mn/Cu helical star-shaped (pine-tree-like) sculptured thin films in surface-enhanced Raman spectroscopy

“…The fourfold symmetry sample spectrum is even inferior to that of 4,4′-bipyridine solution. The latter could be the result of higher symmetry order of this sample [30].…”

Applications of Nanoflowers in Biomedicine

“…Antibacterial properties of nanostructures are due to the very small size and also their large surface-to-volume ratio, making it possible to interact directly with biological membranes and destroy microbial membranes [53]. The bactericidal effect of silver nanoflowers with 3, 4, and 5-fold chiral symmetries was investigated against Escherichia coli, Staphylococcus aureus, and Candida albicans [54]. The silver nanoflowers were synthesized by oblique angle deposition method that is a kind of physical vapor deposition [55].…”