Y and Al co-doped ZnO-nanopowder based ultrasensitive trace ethanol sensor: A potential breath analyzer for fatty liver disease and drunken driving detection

Excess ethanol in exhaled breath can be an indicator of intoxication and a biomarker for fatty liver disease. Herein, we report for the first time a highly sensitive and selective Al and Y co-doped ZnO nanopowder sensor for the detection of trace ethanol in exhaled breath. The nanopowder was synthesized by a facile sol-gel method and characterized by multiple sophisticated techniques, viz. XRD, XPS, FTIR, FESEM, EDX, BET surface area analysis, UV-Vis spectroscopy, photoluminescence, infrared imaging, and current-voltage (I-V) measurement. The developed sensors, especially 5% Y and 1% Al co-doped ZnO exhibited excellent n-type response to 1 ppm ethanol (62.8%). Further, appreciable selectivity to trace ethanol with respect to other interfering gases, viz. acetone, ammonia, CO, NO, NO2, formalin, acetylene, and saturated moisture was observed. Additionally, ultrafast response (0.77 s) and recovery (8.1 s) time, good repeatability, and long-term stability for at least 10 months were observed. Satisfactory resolution between healthy breath, and simulated breath with ethanol vapor excess was obtained. The optimized sensor could be very suitable for both the detection of liver problem as well as commercial breath ethanol analyzer for drunken driving detection.