Multifunctional composites of zwitterionic resins and silver nanoparticles for point-of-demand antimicrobial applications

Abstract Multifunctional composites prepared by rationally combining the antifouling features of zwitterionic materials and bactericidal properties of silver nanoparticles (AgNPs) represent advanced solutions for many bioapplications. Herein, two zwitterionic resins, synthesized by aminolysis followed by carboxymethylation of a divinylbenzene-ethyl acrylate-acrylonitrile copolymer, were used as scaffolds for the in-situ chemical reduction of loaded Ag ions to AgNPs. FTIR spectroscopy demonstrated that the sorption of Ag ions proceeded by a combination of ion exchange and complexation with the zwitterionic beads functional groups. STEM evidenced that the size of the AgNPs formed inside the resins was polydisperse, with irregular shapes. X-ray diffraction analysis demonstrates that crystalline AgNPs are present inside both composite microparticles irrespective of the chemical structure of supporting resin. The AgNPs loaded composite resins presented improved antimicrobial activity against E. coli, S. aureus and C. albicans strains compared to the parent resins and could find potential applications in biomedical field or in water disinfection.