Nitric oxide sensing properties of a surface acoustic wave sensor with copper-ion-doped polyaniline/tungsten oxide nanocomposite film

•Cu2+/PANI/WO3 films were used as sensitive layer for nitric oxide sensing.•A Cu2+/PANI/WO3 coated SAW sensor could detect of NO at ppb levels in air at room temperature.•This work provides a promising approach for sensitive, selective and stable NO gas sensing applications. Copper-ion-doped (Cu2+) PANI/WO3 films with various Cu2+ concentrations were coated onto surface acoustic wave resonators to function as room temperature nitric oxide sensors. Morphological characterization and functionalization of the sensing material were explored using scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. The optimal film was discovered to be a 0.2wt% Cu2+/PANI/WO3 film. The sensor response toward the detection of 1ppb NO at room temperature in dry air was 165Hz and presented a signal-to-noise ratio of approximately 37. The response and recovery times were 59 and 17s when detecting 80ppb NO, respectively. The frequency response was discovered to be linear in the NO concentration range 1–116ppb. The sensor’s sensitivity, reversibility, repeatability, selectivity, and stability were studied for ppb-level NO gas sensing at room temperature in dry air.