The composition and antibacterial properties of copper particles synthesized by a very simple reduction method were studied. For the preparation of particles in knitted fabrics, copper(II) sulfate was used as a precursor and ascorbic acid as a reducing natural agent. X-ray diffraction analysis showed the crystalline nature of the obtained particles. The round or oval particles and their agglomerates in knitted fabrics consisted of copper with traces of copper(I) oxide-cuprite. The element maps and energy dispersive X-ray spectra showed a high content of copper in the samples. The samples of wool and cotton knitted fabrics with copper particles had excellent antibacterial activity against gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli) bacterial strains. The maximum zones of inhibition were 19.3 mm for S. aureus and 18.3 mm for E. coli using wool knitted fabric and 14.7 mm and 15.3 mm using cotton knitted fabric, respectively. The obtained results showed that the modified wool and cotton fabrics are suitable for use as inserts in reusable masks due to their noticeable and long-term activity against pathogenic bacteria.
Keywords: E. coli; S. aureus; antibacterial activity; ascorbic acid; copper particles.