Pt-decorated foam-like Ga-In bimetal oxide nanofibers for trace acetone detection in exhaled breath

Highlights: • Pt decorated GIO nanofibers have been prepared by electrospinning method. • All Pt-GIO sensors show higher sensitivity to acetone than that of GIO sensor. • The detection limit of the 1.2 at% Pt-GIO sensor is as low as 300 ppb. • The 1.2 at% Pt-GIO sensor can detect acetone in exhaust breath. -- Abstract: The concentration of acetone in exhaled breath is an efficient indicator for the diagnosis of diabetes. However, it is difficult to detect acetone in exhaled breath due to the extremely low acetone concentration, rather complex composition and very high humidity. Herein, we report Pt-decorated foam-like Ga-In bimetal oxide nanofibers (Pt-GIO) for trace concentration acetone detection. We found that the Pt-GIO based sensor exhibits enhanced sensing response towards acetone compared with that of Ga-In bimetal oxide (GIO), due to the formation of Schottky contact between Pt and n-type GIO, leading to the increased chemisorbed oxygen. As a result, the Pt-GIO based sensors gives a high response (3.2), short response time (13 s) to 1.8 ppm acetone and very low detection limit (300 ppb). The Pt-GIO sensor also gives good stability and is nearly insensitive to moisture in the range of 40% RH to 95%. These advantages including high response, low detection limit, short response time and high moisture resistance endow Pt-GIO a promising sensing material for acetone detection in exhaled breath.