Differential sensing with imprinted and non-imprinted organic electrochemical transistors reduces calibration drift in wearable sweat cortisol sensors

A differential wearable organic electrochemical transistor pair (MIP cortisol vs NIP) reduces day-to-day calibration drift, cutting inter-day variation by 65%–70% over 14 days in artificial sweat.

• Why it matters: Cortisol sensor outputs drift over days for non-cortisol reasons, making early calibrations unreliable and limiting wearable longitudinal monitoring.
• What they did: They paired a PEDOT:PSS transistor coated with a cortisol molecularly imprinted polymer with a matched non-imprinted polymer device, then subtracted NIP from MIP across four calibrations in artificial sweat over 14 days.
• The result: The MIP-only signal shifted by 15%–22% of its day-1 range, while the differential output shifted by 1%–10%, and day-to-day variation between 1–10 nM fell by 65%–70% on average for individual pairs.

AI summary of the abstract · may contain errors · not medical advice · read the paper.