Siderophores are natural iron chelators that have been evolutionarily selected to bind to Fe ions with very high binding consts. We utilize these unique properties to bind to metal oxide surfaces using a fragment of the cyanobacterial siderophore anachelin. The resulting poly(ethylene glycol) conjugate forms stable adlayers on TiO2 as has been shown by variable angle spectroscopic ellipsometry and XPS. Moreover, these coated surfaces are highly protein-resistant against the adsorption of full human serum.