4-Hydroxythiophenol protected gold nanoclusters supported on a metal surface using a monolayer of 1,9-nonanedithiol as the bridge may transfer charge to the DOPA (3,4-dihydroxyphenylalanine) molecule in solution more efficiently than when the same 4-hydroxythiophenol is assembled in the form of a monolayer directly on the gold substrate. (C) 2003 Elsevier B.V. All rights reserved.