Polymer/silver hybrid thin films forrnanti-pathogenic bacterial applications

摘要

Gold (Au)- and indium-tin-oxide (ITO)-coated glass plates grafted with polymer/silver nanoparticle (Ag NP) hybridrncoatings were prepared and served as biocidal surfaces directed against two biofilm-positive bacteria, namelyrnListeria monocytogenes ATCC 19115 and Staphylococcus aureus ATCC 25923. The polymer films were prepared byrnsurface-initiated radical photopolymerisation of methacrylic acid (MAA) and 2-hydroxyethyl methacrylate (HEMA)rnin the presence of Au or ITO surfaces grafted with photoinitiator groups from diazotised benzophenone or N,Ndimethylaminobenzenediazoniumrntetrafluoroborate (N_2C_6H_4N(CH3)2_BF_4). The Ag NPs were generated in situ on thernpolymer surfaces by reduction of silver nitrate. The degree of biofilm formation by L. monocytogenes ATCC 19115rnand S. aureus ATCC 25923 strains on these surfaces was evaluated. Viable attached cells were quantified using arncolorimetric method based on the ability of viable attached cells to metabolically reduce 3-[4,5-dimethylthiazol-2-yl]-rn2,5-diphenyltetrazolium bromide to a formazan dye. This study shows that diazonium salts permit to anchor robustrnhydrophilic coatings with immobilised Ag NPs of remarkable antifouling properties against pathogenic S. aureus andrnL. monocytogenes bacteria: antifouling due to both hydrophilic MAA and/or HEMA repeat units, and bactericidal duernto the Ag NPs complexed by the COOH groups from MAA repeat units.