Provided is a nitrided metal surface functionalized with molecules, each molecule comprising at least one binding group and an antimicrobial moiety. The molecules are immobilized on the surface by only covalent interactions between the binding groups of the molecules and nitrogen atoms within the nitrided metal surface. Articles comprising the functionalized nitrided surface find use in inhibiting or reducing the growth of microorganisms on surfaces that are frequently touched. A method for preparing the functionalized nitrided surface comprises contacting a nitrided metal surface with molecules so as to form covalent bonds between the binding groups of the molecules and the nitrogen atoms in the surface, thereby immobilising the molecules on the metal surface.
