Breath Acetone Concentration Measured Using a Palm-Size Enzymatic Sensor System

A palm-size electrochemical sensor was developed that utilizes an acetone sensitive enzyme system to amperometrically measure the acetone concentration in human breath. A study of dieting individuals showed an increase in breath acetone from baseline to elevated concentrations as the diet progressed, demonstrating the utility of the device as an indication of the rate of fat metabolism. The sensor response current linearly increased with increasing vapor acetone concentration. The sensor was tested using human breath, and the current response was linear from 0.2 to 10 ppm (v/v). Simulated and human breath results were shown to be comparable, and acetone concentrations out to 24 ppm (v/v) were measured. The enzymatic sensor was capable of detecting the low baseline breath acetone concentrations found in nondieting, nonexercising individuals. The correlation of the enzymatic sensor to the gas chromatograph possessed a linear correlation coefficient greater than 0.950 in all cases.