A series of biomimetic electronic nose nanomaterials of WO3, WO3@PDA, WO3@PDA@CuO, WO3@CuO and CuO were prepared by a facile method and their microstructures, surface chemical composition and sensing ability for acetone odor were investigated systematically by a variety of technologies. The WO3@PDA@CuO and WO3@CuO particles are in nano-sized shape, about 20 nm. The sensing ability to different concentrations acetone odor (50, 100 and 200 ppm) is addressed. The effect of different sensitivity definitions (R-g/R-a or vertical bar R-a - R-g vertical bar/R-a x 100%) on the comparison of experiment results is discussed. The WO3@CuO sensing material shows the best sensing performance of all the sensors, being independent of concentration or sensitivity definitions. These results provide novel insights into the design and preparation of composite electronic nose sensing nanomaterials. (C) 2018 Elsevier Inc. All rights reserved.