Wearable Enzymatic Alcohol Biosensor

Abstract

Transdermal alcohol biosensors have the ability to detect the alcohol that emanates from the bloodstream and diffuses through the skin. However, previous biosensors have suffered from long-term fouling of the sensor element and drift in the resulting sensor readings over time. Here, we report a wearable alcohol sensor platform that solves the problem of sensor fouling by enabling drift-free signals in vivo for up to 24 h and an interchangeable cartridge connection that enables consecutive days of measurement. We demonstrate how alcohol oxidase enzyme and Prussian Blue can be combined to prevent baseline drift above 25 nA, enabling sensitive detection of transdermal alcohol. Laboratory characterization of the enzymatic alcohol sensor demonstrates that the sensor is mass-transfer-limited by a diffusion-limiting membrane of lower permeability than human skin and a linear sensor range between 0 mM and 50 mM. Further, we show continuous transdermal alcohol data recorded with a human subject for two consecutive days. The non-invasive sensor presented here is an objective alternative to the self-reports used commonly to quantify alcohol consumption in research studies.

Wearable Transdermal Alcohol Monitors: A Systematic Review of Detection Validity, and Relationship Between Transdermal and Breath Alcohol Concentration and Influencing Factors

“…Newer-generation wristbands, such the BACtrack Skyn TM (Fairbairn and Kang, 2019) and the Milo ION TM (Lansdorp et al, 2019), have been developed and tested for validity and accuracy of alcohol detection. The Skyn was released for research purposes in 2019.…”

“…An updated search was performed in November 2019 due to relevant new studies being published, including 3 new articles testing new-generation wristbands. This included the BACtrack Skyn TM (Fairbairn and Kang, 2019), the Milo ION TM (Lansdorp et al, 2019), and the Metal OXide (MOX) sensor (Lawson et al, 2019). The studies with the ION and MOX sensors did not validate TAC measures obtained from the monitors, and no correlation or detection rate measures were given.…”

Recent Advances in Skin Chemical Sensors

“…Lansdorp et al (Milo Sensors, Inc.) reported very recently a wearable transdermal alcohol sensor [93] in the form of a wristband, which allows measurements up to 24 h in a row. The detection principle is similar to the one of the previous examples (alcohol oxidase + Prussian blue); it delivers a linear response between 0 and 50 mM.…”

“…( B ) Current measurements using the developed device (grey) and derived equivalent blood alcohol concentration (black), for two periods of 24 h, interrupted by the necessary change of the disposable cartridge. Reproduced from [93]. Creative Commons Attribution License.…”

Biosensors Technologies for Point-of-Care Testing – A Review

“…The evolution of gas sensors for ethanol monitoring was driven by the need for faster and more versatile analytical methods for application in important areas including clinical, diagnostics, food analysis, environmental monitoring and industry analysis. One of the key problems in commercially available devices for ethanol monitoring showing issues from long-term fouling of the sensor element and drift in the resulting sensor readings over time [29]. Here, we present recently presented gas sensors for ethanol surveys, which can provide measurements at room temperature.…”