(Digital Presentation) Electrocatalytic Cortisol Tracing Smart Patch

Abstract

Rapid and continuous tracking of the stress hormone cortisol's circadian rhythm is vital for diagnosing diseases related to chronic stress and adrenal gland disorders [1]. Commercial cortisol sensors relying on labeled enzyme and antibodies suffer from limited stability, lengthy reaction time, and cross-reactivity with analogous molecules [2]. To address these issues, we developed an electrocatalytic sensor using phthalocyanine (Pc) doped molecularly imprinted polymer (MIP) modified screen-printed electrodes for label-free, reagentless, sensitive, and selective electrochemical detection of cortisol. The sensor was constructed via one-step electropolymerization of conductive prepolymer in the presence of Pc and template cortisol. The controlled release of cortisol templates resulted in an MIP network embedded with Pc catalysts in the vicinity of the cortisol-specific binding cavities. The sensor directly measures the cortisol level by catalysing the reduction reaction of the cortisol captured by the cavities of the MIP. Proof of studies was performed to detect cortisol over a wide concentration range varying from 500 pM to 10 µM with high selectivity against structurally similar hormones. The facile label-free and antibody-free cortisol sensor on a wearable smart patch offers an appealing approach for selective steroid hormone detection at point-of-care testing.