Flexible, low volume detection of chronobiology biomarkers from human sweat.

Chronobiology is defined as the temporal fluctuations occurring in the human physiology due to the circadian cycle. These fluctuations are good indicators of the functioning of the Hypothalamic-Pituitary-Adrenal axis (HPA axis) and can be tracked by using biomarkers: cortisol and DHEA. Low volume tracking systems will be beneficial for patients exposed to chronic stress, patients suffering from endocrine conditions manifested by circadian disruption and act as a lifestyle monitoring tool. The sensor system demonstrated in this work was an affinity-based system, characterized using EIS (Electrochemical Impedance Spectroscopy).The sensor can detect cortisol and DHEA in the physiologically relevant ranges i.e. 8-200 ng ml-1 and 2-131 ng ml-1 respectively. Thus, the senor is a non-invasive, label free, cost-effective solution for tracking chronobiology for circadian diagnostics.