Highly responsive diabetes and asthma sensors with WO3 nanoneedle films for the detection of biogases with low concentrations

A diabetes sensor was developed to detect low concentrations of acetone gas, which is a diabetes biomarker. A WO3 nanoneedle film was synthesized via an aqueous process for use as a sensitive sensing membrane. Acetone was adsorbed and oxidized on the WO3 nanoneedle film, which changed the sensor resistance. The sensor exhibited a high response of Ra/Rg = 19.72, where Ra is the sensor resistance in air, and Rg is the sensor resistance in air containing 10 ppmv acetone gas. The sensor also exhibited a high response (25.36) to 1 ppmv NO2, which is related to asthma. Furthermore, the sensor responded to various biogases associated with diseases. The sensor responses to 10 ppmv of the lung cancer marker gases acetaldehyde and toluene were 13.54 and 9.49, respectively. The sensor responses to 10 ppmv isoprene, ethanol, para-xylene, hydrogen, and NH3 were 7.93, 6.33, 4.51, 2.08, and 0.90, respectively. Trace amounts of acetone and NO2 gases (25 and 250 ppbv, respectively) were detected. The limits of detection for acetone and NO2 gases were estimated to be 2.4 and 1.5 ppbv, respectively. The sensor exhibited superior ability to detect low concentrations of biomarker gases. The unique characteristics of the WO3 nanoneedle film contributed to its high response rates. A WO3 nanoneedle film was developed for a gas sensor to detect low concentrations of acetone gas, which is a diabetes biomarker. The sensor exhibited a high response (19.72) to 10 ppmv acetone gas. The sensor also exhibited a high response (25.36) to 1 ppmv NO2, which is related to asthma. The limits of detection for acetone and NO2 gases were estimated to be 2.4 and 1.5 ppbv, respectively. The sensor exhibited superior ability to detect low concentrations of biomarker gases. The unique characteristics of the WO3 nanoneedle film contributed to its high response rates.