In situ synthesis of gold nanoparticles on cotton fabric for multifunctional applications

Gold nanoparticles (AuNPs) were synthesized in situ on cotton, one of the most popular cellulose materials, to achieve functionalization. The localized surface plasmon resonance of the AuNPs imparted the cotton fabric with colors, showing good colorfastness to washing and rubbing. Characterization of the surface morphology and chemical composition of the modified cotton fabric confirmed synthesis and coating of the AuNPs on cotton fibers. The relationship between the morphology of the AuNPs and the optical properties of the cotton fabric was analyzed. Acid condition enabled in situ synthesis of AuNPs on cotton. Cotton with AuNPs exhibited significant catalytic activity for reduction of 4-nitrophenol by sodium borohydride, and could be reused in this reaction. Treatment with AuNPs substantially improved the ultraviolet (UV)-blocking ability of the fabric and resulted in cotton with remarkable antibacterial activity. Traditional reactive dyes were applied to the cotton with AuNPs to enhance its color features. The catalytic properties of the AuNPs on the fabric were not influenced by dyeing with traditional dyes. AuNP-treated cotton fabric used as a flexible active substrate showed improved Raman signals of dyes on the fabric.