Self-assembled AuNPs for ingrain pigmentation of silk fabrics with antibacterial potency

Nanogold was self-assembled for ingrain pigmentation of silk fabric with antibacterial properties. The functional groups of silk macromolecular polymeric chains were exploited for generation and stabilization of nanogold. Hydrogen peroxide was used for activation of silk molecular chains through increasing their reactivity and accessibility to be functionalized as manufacturer of nanogold without using any external agents. Effect of procedure sequencing was studied through addition of peroxide firstly (group A) and with Au salt (group B). Self-assembly of nanogold inside fabric was confirmed by electron microscope, X-ray diffraction and absorbance spectra. The particle size of the nanogold within fabric was estimated to be in range of 22-66 nm (group A) and 18-49 nm (group B). Due to LSPR of nanogold, silk fabrics were acquired violet color with good fastness properties. In distilled water and artificial sweat, 33.5-41.0% and 46.2-50.4% of Au was leached out from silk fabric, respectively after 24 h. Very good antibacterial properties were estimated for ingrain colored fabric against E. coli and S. aureus via using the optical density measurements. Quite simplicity, timelessness and energy saving are advantages which were realized in the current work for silk functionalization.