Bactericidal Cotton Fabrics Modified By Silver and Copper Nanoparticles: Optical Spectra, Structures, Electrical Resistance

The bactericidal activity, optical spectra, electron-microscopic images and electrical resistance of cotton textile modified with bimetallic silver/copper nanoparticles (Ag/CuNPs) against the series of the microorganisms (Escherichia coli, Staphylococcus aurous, and Pseudomonas aeruginosa) are studied. NPs’ modified fabrics were produced by the developed by us method of soft heat treatment of tissue impregnated with silver and copper ions and characterized by the Diffusion-Reflectance Spectra (DRS), SEM, electrical resistance and the flame atomic absorption spectroscopy (FAAS) methods. Glucosidal residues of cotton participate in the reduction of silver ions to NPs, besides that fabrics contain Ag/Cu2O (marked as Ag/Cu NPs) nanosized compositions with the size of 20 60 nm. The FAAS method has been used to determine the quantitative Cu:Ag ratio within the Ag/CuNPs/tissue structures. Dried bactericidal fabric does not have electrical conductivity indicating the absence of contact between particles, fixed in the tissue structure. The electrical resistance of fabrics decreases sharply upon wetting in the water or electrolyte solution. The increasing of the conductivity of the modified fabrics suggests the diffusion of corresponding metal ions from the surface of NPs in the tissue which may contribute to the direct interaction of bactericide agents with microbes in biological fluids. Obtained composites demonstrated excellent antimicrobial activity.