Surface-doped Ru over WO₃ nanocubes for highly selective and ppb-concentration 1-octen-3-ol sensing

The newly-emerged gas sensing detection of 1-octen-3-ol biomarker is expected to indirectly monitor foodborne illnesses caused by Salmonella-contaminated meat, which requires high selectivity and a ppb-concentration detection limit. Here, surface-doped ruthenium over tungsten oxide nanocubes (Ru/WO₃ NCBs) have been synthesized by a wet-chemical approach for highly selective and ppb-concentration 1-octen-3-ol sensing. As-prepared Ru/WO₃ NCBs exhibit a polycrystalline structure and consist of NCBs that have an average side length of ∼131 nm, and the Ru/WO₃ NCBs show a high sensing response toward 5 ppm 1-octen-3-ol (R_a/R_g = 406), excellent selectivity, 50 ppb detection limit, 70 % relative humidity tolerance, and 54 days stability at 220 °C. The excellent sensing performance might be attributed to the electronic and chemical sensitization of Ru, which thickens the electron depletion layer and increases adsorbed oxygen to promote interfacial electron transfer and 1-octen-3-ol oxidation. Practically, Ru/WO₃ NCBs have been integrated into a sensing device to simulate detecting 1-octen-3-ol, which has the potential for Salmonella detection in the future.