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. The binding group is a carboxyl and at least some of the molecules consist of antimicrobial moiety. Preferably, the molecule or the antimicrobial moiety is a peptide or fragment thereof. The exemplified peptide is derived from defensin. The metal may be steel, iron, titanium, aluminium, chromium, molybdenum or an alloy thereof. Also claimed are articles comprising the functionalized nitrided surface which find use in inhibiting or reducing the growth of microorganisms on surfaces that are frequently touched. The article may be part of a worktop, chair, desk, table, door, handle, railing, keyboard or medical device. A method for preparing the functionalized nitrided surface is also claimed.
