Synthesis of sericin-coated silver nanoparticles and their applications for the anti-bacterial finishing of cotton fabric

Abstract Cotton fiber is a commonly used and highly compatible natural cellulose fiber. However, bacterial growth always affects people’s health. In this study, natural sericin extract, obtained from degumming treatment on silk cocoons, was proposed as a reducing agent and dispersant to prepare well-dispersed Ag nanoparticles (NPs), which showed strong adsorption capacity on amino cotton fabric to complete anti-bacterial modification. A series of characterizations, including ultraviolet-visible spectroscopy, transmission electron microscopy, ZETA potential, field emission scanning electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy, and inductively coupled plasma atomic emission spectrometry, were used. The results showed that Ag + could be reduced to Ag 0 by sericin extract and formed a stable sol-like product in situ with a particle size of 12 nm. After soaking in the system, Ag NPs could successfully coat on amino cotton fabric. Significantly, sericin Ag NP-coated amino cotton fabric showed an anti-bacterial rate of more than 98% against Escherichia coli and Staphylococcus aureus , and there was no significant change after washing 20 times. We believe that the prepared anti-bacterial fabric has great potential for scalable production and practical applications.