Antimicrobial treatment for textiles based on flavonoid-mediated silver nanoparticles dispersions

Abstract

The use of “green” reagents for silver nanoparticles (AgNPs) synthesis represents an attractive alternative to conventional methods, due to the abundance of available biomass with reducing properties. Herein, a flavonoid compound, hesperidin, was used to produce AgNPs, and the resulting dispersion was applied to textile fabrics and tested for its antimicrobial properties. Different ratios of flavonoid to the silver precursor (v:v) were prepared. The formation of the nanoparticles was indicated by the presence of the SPR specific band in the UV–Vis spectra. For the synthesis optimization, the DLS technique was used to determine the size and polydispersity of the AgNPs, while zeta potential measurements were performed to assess their physical stability. For the dispersion with the optimal ratio, particles with the average size (Zav ) of 93.55±3.51 nm were obtained, with a polydispersity index (PdI) of 0.259. For this ratio, the value of the zeta potential (ξ.) was –28.80±1.54 mV, indicating that the dispersion is physically stable. The nanoparticles were further characterized using SEM-EDS techniques to confirm the particles' nature and evaluate their morphology. The AgNPs were deposited on textile samples, by direct soaking into the dispersion. The distribution of the AgNPs on the textile samples fibres was evaluated by SEM and the chromatic parameters L*a*b* were determined compared to the untreated samples. Antimicrobial tests were conducted against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis strains, according to the ISO 20743:2013 standard, and percentages of bacterial reduction up to 99.99% were obtained.