Molecularly imprinted polymer on roll-to-roll printed electrodes as a single use sensor for monitoring of cortisol in sweat

Cortisol is involved in regulating many human physiological functions, with cortisol imbalance capable of causing adverse mental and physical health conditions. Existing tools for monitoring of cortisol can assist in alerting the need for mediation strategies, but these typically require time consuming processes such as sample preparation followed by laboratory analysis. This work demonstrates a miniature flexible sensor patch incorporating electrode structures produced by high throughput roll-to-roll rotary screen-printing process, which are subsequently functionalized by electropolymerization of a polypyrrole/Prussian blue molecularly imprinted polymer for measuring cortisol by chronoamperometry. The developed single use sensor patch provides acceptable selectivity for cortisol and operates in artificial eccrine perspiration across a broad concentration range of 0.1-10 000 ng ml-1 (R 2 = 0.916). In the application of measuring thermally induced sweat, the sensor provided results in agreement with the natural circadian rhythm of fluctuating cortisol.