Nanocrystalline composed SnO2 inverse opal for highly sensitive acetone gas sensor at ppb-level

Abstract

The exhaled acetone concentration of diabetic patients is much higher than that of normal persons, which can be used for early warning, large-scale screening, and adjuvant treatment for diabetes. Therefore, a non-invasive exhaled acetone sensor with a low detection limit, high sensitivity, and high reliability is widely studied. Their sensing performance largely depends on the chemical composition of sensing materials, surface modification, the microstructure of the sensing layer. In this paper, Tin oxide (SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ) nanocrystalline composed inverse opal structure were successfully prepared, using polystyrene microspheres as templates, as a sensing material for an acetone gas sensor. Compared with pure SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> prepared by the hydrothermal method, inverse opal SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> has a much higher response at a low concentration of 500ppb-10ppm, Up to 5.6 response at 1ppm(240°C), which is already suitable for diabetes screening without doping noble metal. The improvement of gas sensitivity is mainly due to the small size of the SnO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> nanoparticles and the pore structure composed of the nanocrystalline. The relatively high response, fast response and recovery speed, and good stability make it a promising gas sensor material for screening and monitoring of diabetes.