Selectivity towards methyl mercaptan of Pt-PtO functionalized WO3 nanostructures made by flame spray pyrolysis

• 0–1 wt% Pt-PtO functionalized WO 3 nanostructures were synthesized by flame spray pyrolysis (FSP). • 1–3 nm Pt-PtO core-shell nanoparticles were decorated on 5–20 nm WO 3 nanoparticles. • The CH 3 SH response of 204 to 500 ppb CH 3 SH at the best sensing temperature of 250°C with a low detection limit of 26 ppb. • The sensor exhibited high CH 3 SH selectivity relative to volatile sulfur compounds (VSCs), volatile organic compound (VOCs), volatile organic acids (VOAs) or short-chain fatty acids (SCFAs), toxic and flammable gases . • The flame-synthesized Pt-PtO functionalized WO 3 nanosensors could be potential for CH 3 SH detection at ppb levels in the medical applications . This work presented 0–1 wt% Pt-PtO functionalized WO 3 nanostructures synthesized by flame spray pyrolysis (FSP) for methyl mercaptan (CH 3 SH)-sensing applications. According to electron microscopic and X-ray spectroscopic analysis, 1–3 nm Pt-PtO core-shell nanoparticles were decorated on 5–20 nm primary monoclinic WO 3 nanoparticles. The gas-sensing data revealed that Pt-PtO loading with an optimum Pt content of 0.5 wt% provided a remarkably enhanced CH 3 SH response of 204 to 500 ppb CH 3 SH at the best sensing temperature of 250°C with a low detection limit of 26 ppb and high CH 3 SH selectivity relative to (CH 3 ) 2 S, H 2 S, CH 3 OH, C 2 H 5 OH, C 3 H 6 O, NH 3 , NO 2 , H 2 , CH 4 , C 2 H 2 and short-chain fatty acids (SCFAs) including CH 3 COOH, C 2 H 5 COOH, C 3 H 7 COOH. Therefore, the flame-synthesized Pt-PtO functionalized WO 3 nanosensors could be potential for CH 3 SH detection at ppb levels in the medical applications particularly noninvasive breath diagnosis of halitosis and serious infection of periodontitis. Flame-synthesized Pt-PtO functionalized WO 3 nanosensors could be potential for selective CH 3 SH detection at ppb levels for noninvasive breath diagnosis of halitosis and periodontitis.