A breath analyte device includes a breath volume in fluid communication with a sampling volume. The device also includes a sampling sensor configured to generate a breath signal that varies in response to changes in gas pressure (e.g., sound waves) in the breath volume and an analyte sensor configured to generate an analyte signal that varies in response to a concentration of a target analyte present in the sampling volume. A control unit is configured to determine a time at which to measure the concentration of the target analyte in the sampling volume based on the breath signal and measure the concentration of the target analyte in the sampling volume based on the analyte signal at the determined time. The device may also include a pump configured to motivate gas from the breath volume into the sampling volume prior to measuring the concentration of the target analyte.