Noninvasive Concept for Optical Ethanol Sensing on the Skin Surface with Camera-Based Quantification.

Law enforcement and the general public do not yet have adequate means of assessing and preventing drunk driving. Blood alcohol concentration (BAC) is unable to be determined on-site, as it typically requires the use of complex chromatographic methods. Breathalyzers have been well established in law enforcement for correlating breath alcohol concentrations (BrAC) to BAC estimations, as they involve portable equipment with rapid analysis times. Although these BrAC measurements allow police officers to determine probable cause and to arrest an intoxicated driver at the scene, the results are preliminary and are not often considered as evidence in court. A new, noninvasive method was developed to assess an individual's level of intoxication based on the presence of ethanol in sweat on the skin surface. This intuitive system uses two enzymes, alcohol oxidase and horseradish peroxidase, to correlate ethanol sweat concentrations to the production of a color that is visible to the naked eye. The results of the controlled drinking study demonstrate the ability of both the spectrophotometric and the visualization system to quantify the amount of ethanol within authentic sweat samples collected from individuals who had consumed an alcoholic beverage. The pictorial analysis allows for the system to be analyzed without the use of a UV-vis spectrophotometer. With this method, a smartphone application would be capable of documenting and evaluating the intoxication levels of an individual based on sweat ethanol levels. The developed alcohol sensing system has the potential to impact both the general public and law enforcement, as well as the fields of forensic and biomedical science.