Wearable Microsensor Array for Multiplexed Heavy Metal Monitoring of Body Fluids

TLDR

The study presents a flexible, wearable microsensor array for simultaneous monitoring of heavy metals in human body fluids to inform health status and support clinical investigations. The array uses electrochemical square wave anodic stripping voltammetry on gold and bismuth microelectrodes, incorporates skin‑temperature compensation, and is validated against ICP‑MS while enabling real‑time sweat monitoring of zinc and copper. The sensors exhibit high selectivity, repeatability, and flexibility, with sweat and urine measurements matching ICP‑MS results and allowing real‑time tracking of metal concentration changes.

Abstract

A flexible and wearable microsensor array is described for simultaneous multiplexed monitoring of heavy metals in human body fluids. Zn, Cd, Pb, Cu, and Hg ions are chosen as target analytes for detection via electrochemical square wave anodic stripping voltammetry (SWASV) on Au and Bi microelectrodes. The oxidation peaks of these metals are calibrated and compensated by incorporating a skin temperature sensor. High selectivity, repeatability, and flexibility of the sensor arrays are presented. Human sweat and urine samples are collected for heavy metal analysis, and measured results from the microsensors are validated through inductively coupled plasma mass spectrometry (ICP-MS). Real-time on-body evaluation of heavy metal (e.g., zinc and copper) levels in sweat of human subjects by cycling is performed to examine the change in concentrations with time. This platform is anticipated to provide insightful information about an individual's health state such as heavy metal exposure and aid the related clinical investigations.