Fig. 7: Real-time monitoring of exhaled breath ethanol concentration using the sensor.

a Schematic illustration of the experimental setup. The subject consumed 200 mL of beer every 10 min, with BrAC measurements taken prior to each intake. Breath ethanol concentration was measured using two devices: a commercial breathalyzer (Alcoscan AL8800, Sentech Korea Corp.) as a reference, and the developed ethanol sensor integrated with a measurement system. b BrAC response recorded over time. The developed ethanol sensor demonstrated a strong correlation with the reference breathalyzer, effectively tracking changes in breath ethanol concentration. The sensor successfully captured transient ethanol spikes and exhibited a rapid response to alcohol intake, confirming its potential for real-time breath alcohol monitoring applications