A new electrochemical sensor for determination of 2,4,6-trichlorophenol (2,4,6-TCP) was fabricated. The characterization of the sensor was studied by scanning electron microscopy, electrochemical impedance spectroscopy and cyclic voltammetry techniques. The electrochemical behavior of 2,4,6-TCP was investigated using cyclic voltammetry and differential pulse voltammetry at the HS-b-cyclodextrin (HS-beta-CD)/gold nanoparticles (AuNPs) composite modified indium tin oxide (ITO) electrode. The results showed that the current responses of 2,4,6-TCP greatly enhanced due to the high catalytic activity and enrichment capability of composites. The peak current of 2,4,6-TCP increases linearly with the increase of the 2,4,6-TCP concentration from 3.0 x 10(-9) to 2.8 x 10(-8) M, with the limit of detection of 1.0 x 10(-9). Further more, the modified electrode was successfully applied to detect the level of 2,4,6-TCP in tap water samples with excellent sensitivity. (C) 2015 Elsevier Ltd. All rights reserved.