The aggregation of amyloid-beta (A beta) is an important pathologic feature of Alzheimer's disease (AD) that leads to the formation of neuronal plaques.. A rapidly growing number of polyphenols have been intensively investigated for AD treatment. In this report, the interaction of a polyphenolic compound, resveratrol, with A beta was studied using electrochemical impedance spectroscopy (EIS). The growth of A beta fibrils was facilitated with the incubation of oligomer-modified electrodes with free A beta in solution. Resveratrol significantly slowed down the formation of A beta aggregates, which was monitored by following the changes in the charge transfer resistance (R-ct) values. The moderating effect of resveratrol on A beta aggregation was also confirmed with Thioflavin T (ThT) fluorescence assay and transmission electron microscopy (TEM) imaging. Results obtained from EIS correlated well with the ThT fluorescence assay and suggested that EIS was a promising method for the analysis of A beta aggregation in the presence of novel A beta-targeting compounds toward AD therapy. (C) 2013 The Electrochemical Society. All rights reserved.