Au-modified three-dimensional In2O3 inverse opals: synthesis and improved performance for acetone sensing toward diagnosis of diabetes

Abstract

Analyzing the volatile organic compounds (VOCs) in exhaled breath effectively is crucial to medical treatment, which can provide a fast and noninvasive way to diagnose disease. Well-designed materials with controlled structures have great influence on the sensing performance. In this work, the ordered three dimensional inverse opal (3DIO) macroporous In₂O₃ films with additional via-hole architectures were fabricated and different amounts of gold nanoparticles (Au NPs) were loaded on the In₂O₃ films aiming at enhancing their electrical responses. The gas sensing to acetone toward diabetes diagnosis in exhaled breath was performed with different Au/In₂O₃ electrodes. Representatively, the best 3DIO Au/In₂O₃ sensor can detect acetone effectively at 340 °C with response of 42.4 to 5 ppm, the actual detection limit is as low as 20 ppb, and it holds a dynamic response of 11 s and a good selectivity. Moreover, clinical tests proved that the as-prepared 3DIO Au/In₂O₃ IO sensor could distinguish acetone biomarkers in human breath clearly. The excellent gas sensing properties of the Au/In₂O₃ electrodes were attributed to the “spillover effects” between Au and In₂O₃ and the special 3DIO structure. This work indicates that 3DIO Au/In₂O₃ composite is a promising electrode material for actual application in the monitoring and detection of diabetes through exhaled breath.