Electroless silver plating on fabrics for antimicrobial coating: comparison between cotton and polyester

In the past few years, due to the Covid-19 pandemic, the interest towards textiles with antimicrobial functionalities faced a significant boost. This study proposes a rapid and convenient method, in terms of reactants and equipment, for fabricating antimicrobial coatings on textiles. Through the electroless silver plating reaction, silver coatings were successfully applied on cotton and polyester, rapidly and at room temperature. Functionalized samples were characterized by morphological (optical and scanning electron microscopies) and chemical tests (X-ray photoelectron spectroscopy, XPS) to investigate the nature of the silver coating. Although distinct nanoparticles did not form, XPS analysis detected the presence of silver, which resulted in an increased surface roughness and hydrophobicity of both cotton and polyester textiles. Ag-coated samples exhibited approximately 80% biocompatibility with murine L929 fibroblasts or human HaCaT cells, and strong antibacterial properties against Escherichia coli in direct contact tests. In antiviral experiments with SARS-CoV-2 virus, treated cotton showed a 100% viral reduction in 30 min, while polyester achieved 100% reduction in 1 h. With a human norovirus surrogate, the Feline Calicivirus, both treated textiles have a faster antiviral response, with more than 60% viral reduction after 5 min, while achieving a 100% reduction in 1 h. In conclusion, this study presents a fast, efficient, and low-cost solution for producing antimicrobial textiles with broad applications in medical and healthcare scenarios.