Highly selective 1-octen-3-ol gas sensor based on nest-like WO3 decorated by FeCo nanoalloys for monitoring of moldy wheat

1-Octen-3-ol is a characteristic volatile organic compound released from moldy wheat. Therefore, the development of high-performance gas sensors for 1-octen-3-ol detection is of great significance for ensuring grain safety by enabling real-time monitoring of wheat quality. However, substantial challenges remain, including poor selectivity and insufficient stability. To address these limitations, this study designed and successfully synthesized a three-dimensional nest-like Tungsten trioxide (WO 3 ) structure decorated with FeCo nanoalloys. By modulating the loading amount of the iron (Fe) cobalt (Co) alloy, we achieved precise tuning of surface oxygen vacancies and facilitated efficient electron transfer within the nanocomposite, resulting in a significantly enhanced gas response. The optimized 1.5FeCo@WO 3 sensor exhibited a high response value of 12.68 toward 100 ppm 1-octen-3-ol, along with superior selectivity and excellent long-term stability. Systematic material characterizations, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) analyses, confirmed that the composite possesses a high specific surface area, abundant oxygen vacancies, and a robust interfacial electronic interaction between the FeCo alloy and the WO 3 matrix. Furthermore, density functional theory calculations were integrated into the mechanistic analysis. Consequently, this work yields a promising sensor candidate for the early warning of wheat diseases and proposes a material design strategy for developing economical, high-sensitivity gas sensors for agricultural applications.