Contact-active microbicidal gold surfaces using immobilization of quaternary ammonium thiol derivatives

Contact-active auto-bactericidal surfaces were obtained by grafting of specially designed thiol derivatives containing antimicrobial quaternary ammonium moieties on gold substrates. The formation and quality of the self-assembled monolayers (SAMs) were characterized by X-ray photoelectron spectroscopy, cyclic voltammetry and contact angle measurements. The bactericidal activity of the modified gold surface was evaluated against Staphylococcus aureus using an original procedure. This activity was demonstrated to be dependent on the length of the alkyl chain borne by the charged nitrogen atom of the quaternary ammonium moiety, and on the contact time. Thiol derivatives containing a quaternary ammonium group bearing variable alkyl chains were synthesized and grafted on gold substrates for obtaining contact-active auto-bactericidal surfaces. The bactericidal activities of grafted surfaces were evaluated against Staphylococcus aureus. [Display omitted]