Ultrafine Ir-IrO2 nanoparticles for decoration of cobalt phthalocyanine films as an active component for highly sensitive detection of nitric oxide

https://doi.org/10.1016/j.mseb.2025.118074

Nitric oxide is an important molecule that plays a crucial role in regulating physiological processes in mammals. To develop a sensitive method for detecting NO, new heterostructures based on cobalt phthalocyanine (CoPc) films decorated with Ir-IrO₂ nanoparticles were considered as active layers of chemiresistive sensors for the direct NO detection. Within deposition conditions, Ir-IrO₂ nanoparticles with an Ir concentration of 0.48–1.5 µg/cm², a fraction of IrO₂ phase of 10–20 %, and particles sizes from 1 to 3 to 14 nm were obtained on the surface of CoPc films. The influence of these parameters of Ir-IrO₂ particles on the sensor response of Ir-IrO₂/CoPc heterostructures to NO was investigated using theoretical and practical approaches. Based on DFT calculations, an electronic sensitization mechanism of NO detection by Ir-IrO₂/CoPc heterostructures was proposed. These heterostructures are able to detect of NO gas at the ppb level and show the selectively to NO_x in the presense of other gases.