Terbium-doped US nanocrystals capped with thiosalicylic acid were characterized by means of optical spectroscopy. The results reveal strong differences between dynamics of terbium-related photoluminescence in thiosalicylic complex and US nanocrystals. Our interpretation is based on the capping acid binding modes towards terbium and cadmium ions on the US nanocrystals surface. (C) 2003 Elsevier B.V. All rights reserved.