Zn(II)-induced aggregation of A beta peptides is a key molecule feature of Alzheimer's disease (AD). Here we study the effect of zinc ion on prefibrillar oligomerization of A beta peptides at nanomolar concentration on highly oriented pyrolytic graphite (HOPG) by atomic force microscope (AFM). The results demonstrate that the introducing of zinc ion promotes the prefibrillar oligomerization of A beta peptides and the initial nanocoins are transformed into nanobelts. The research may facilitate the understanding of pathology of Alzheimer's disease and suggest a rational design of potent inhibitor preventing the fibril growth of A beta peptides. (C) 2014 Elsevier B.V. All rights reserved.