A novel electrochemical sensor was constructed for sensitive and selective determination of carbamazepine (CBZ). First trimetallic Au core AgPd shell nanoparticles (Au@AgPdNPs) with dendritic morphology were synthesized by a facile method and then the nanocomposite of Au@AgPdNPs, macrocyclic beta-cyclodextrin and butyl-3-metylimidazolium bis (trifluorometylsulfonyl) imide ionic liquid was prepared to modify a glassy carbon electrode. The formation of Au@AgPdNPs was characterized using transmission electron microscopy (TEM) and energy dispersion spectroscopy (EDS). The surface morphology of the modified electrode was characterized by scanning electron microscopy (SEM). Electrochemical methods including cyclic voltammetry (CV) and square wave voltammetry (SWV) were used to study the electrochemical behavior of CBZ. The effect of several relevant operating parameters was investigated and optimized. Under the optimized experimental conditions, the calibration curve was linear within the concentration ranges of 0.5 mu M to 90 mu M of CBZ with a limit of detection (LOD) of 0.089 mu M. Also, the reproducibility, repeatability and stability of the constructed electrochemical sensor, were all found to be satisfactory. Finally, the proposed sensor was successfully employed for the direct determination of CBZ in in real samples. (C) 2017 The Electrochemical Society. All rights reserved.