Novel N-chloramine precursors for antimicrobial application: synthesis and facile covalent immobilization on polyurethane surface based on perfluorophenyl azide (PFPA) chemistry

To control the pathogen cross contaminations on medical material surface, there is a pressing need to develop antimicrobial materials with highly efficacious surface biocidal activity. In this work, N-chloramine precursors containing a quaternary ammonium unit and perfluorophenyl azide unit were synthesized and covalently immobilized on inert polyurethane (PU) film upon UV light irradiation. The surface modification was confirmed by contact angle, Fourier transform infrared (ATR FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) analyses. After bleaching treatment, satisfactory biocidal activity was achieved for the surface-modified PU films. It was found that the introduced surface QA center contributed an even faster surface contact killing behavior and that precursors with a longer structural linker caused higher surface chlorine content and higher antimicrobial efficacy. This approach provides a novel and facile method that enables the covalent immobilization of N-chloramine precursors on inert polymeric surface to produce durable antimicrobial materials