Wholistic Electrochemical Biosensor for the Combinatorial Detection of Alcohol and Glucose in Perspired Sweat

Abstract

In this paper, we demonstrate a novel, flexible electrochemical biosensor of the simultaneous detection of glucose and alcohol in perspired human sweat for wearable sensing applications. Evaluation of bodily fluids such as blood, sweat, urine has allowed patients and health-care professionals to track their vital parameters reliably through non-invasive monitoring. Human sweat is one such fluid that contains valuable medical information which can be used to develop real-time, healthcare management devices. Literature studies have shown that sweat alcohol content (SAC) is well correlated to blood alcohol content (BAC). Alcohol consumption modifies blood glucose levels of a diabetic individual depending on their nutrition state inducing either hypoglyceamia or hyperglyceamia. The motivation of this study was to build a sweat based sensor platform for alcohol and glucose management to monitor glucose levels on moderate consumption of alcohol of diabetic social drinkers in low volumes of sweat. The developed sweat biosensor employs a metal- metal oxide electrode stack on a flexible substrate for the non-invasive, low- volume detection of a cohort of glucose and alcohol molecules in sweat through a stable enzyme immunoassay chemistry. Non-faradaic electrochemical impedance spectroscopy (EIS) is the signal transduction mechanism used to detect the presence of glucose and alcohol in sweat. The detection of these molecules is achieved by measuring impedance changes occurring at the electrode- electrolyte interface due to the formation of electrical double layer. Binding events and enzyme catalysis reactions modulate the electrical double layer (EDL) which contribute to the overall impedance change of the system. Detection of sweat glucose levels in the presence of alcohol is demonstrated on the sensor systems at a specific frequency.