Abstract
As a key biomarker for noninvasive diagnosis of diabetes,the selective detection of trace acetone in ex-haled gas using a portable and low-cost device remains a great challenge.Semiconductor metal oxide(SMO)based gas sensors have drawn signification attention due to their potential in miniaturization,user-friendliness,high cost-effectiveness and selective real-time detection for noninvasive clinical diag-nosis.Herein,we propose a one-pot solvent evaporation induced tricomponent co-assembly strategy to design a novel ordered mesoporous SMO of silica-implanted WO3(SiO2/WO3)as sensing materials for trace acetone detection.The controlled co-assembly of silicon and tungsten precursors and amphiphilic diblock copolymer poly(ethylene oxide)-block-polystyrene(PEO-b-PS),and the subsequent thermal treat-ment enable the local lattice disorder of WO3 induced by the amorphous silica and the formation of ordered mesoporous SiO2/WO3 hybrid walls with a unique metastable e-phase WO3 framework.The ob-tained mesoporous SiO2/WO3 composites possess highly crystalline framework with large uniform pore size(12.0-13.3 nm),high surface area(99-113 m2/g)and pore volume(0.17-0.23 cm3/g).Typically,the as-fabricated gas sensor based on mesoporous 2.5％SiO2/WO3 exhibits rapid response/recovery rate(5/17 s),superior sensitivity(Rair/Rgas=105 for 50 ppm acetone),as well as high selectivity towards acetone.The limit of detection is as low as 0.25 ppm,which is considerably lower than the thresh value of acetone concentration(＞1.1 ppm)in the exhaled breath of diabetic patients,demonstrating its great prospect in real-time monitoring in diabetes diagnosis.Moreover,the mesoporous 2.5％SiO2/WO3 sensor is integrated into a wireless sensing module connected to a smart phone,providing a convenient real-time detection of acetone.
维普
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