Multiplex ovarian hormone monitoring in sweat using a dual-aptamer wearable sensor.

Estradiol (E2) and progesterone (P4) jointly regulate reproductive function, menopausal transition, and hormone-therapy response, yet their assessment relies on intermittent blood sampling that provides only snapshots of dynamic endocrine processes. We report a wearable sweat sensor for multiplex E2 and P4 monitoring. Two redox-orthogonal aptamer-reporter systems, encoded by methylene blue and ferrocene, are integrated on a single inkjet-printed gold electrode, enabling independent quantification of the hormones through sequential square-wave voltammetry scans at physiologically relevant picomolar concentrations. An integrated passive microfluidic module normalizes sweat pH and ionic strength before analysis, eliminating auxiliary correction channels and enabling consistent operation across different sweat-induction methods and body locations. In a single-subject feasibility study spanning reproductive, perimenopausal, and postmenopausal participants, measurements agreed with laboratory reference assays and enabled longitudinal tracking of ovarian hormone dynamics. This approach establishes a strategy for multiplex wearable endocrine profiling and motivates larger cohort studies for personalized women's health monitoring.