Logo image
Back
Hydrogel-based sweat chloride sensor with high sensitivity and low hysteresis
Journal article   Peer reviewed

Hydrogel-based sweat chloride sensor with high sensitivity and low hysteresis

Wanqing Zhang, Xianzhe Zhang, Ankan Dutta, Farnaz Lorestani, Md Abu Sayeed Biswas, Bowen Li, Abu Musa Abdullah and Huanyu Cheng
Biosensors & bioelectronics, v 288, 117805
15 Nov 2025
DOI: https://doi.org/10.1016/j.bios.2025.117805
PMID: 40730067
url
https://pmc.ncbi.nlm.nih.gov/articles/PMC13081639/View
Open

Abstract

Monitoring chloride ions (Cl ) in sweat is critical for assessing hydration, diagnosing cystic fibrosis (CF), and evaluating other health conditions. Existing wearable sweat chloride sensors either exhibit low sensitivity based on potentiometric sensing or irreversible readings based on colorimetric sensing. To address these challenges, we report the design of a hydrogel-based wearable sweat sensor that allows for monitoring of Cl based on an electrolyte concentration gradient. This reported sensor features a coplanar design with a cation-selective hydrogel (CH), a high-salinity hydrogel (HH), and a sweat chamber. The gradient between the HH and the sweat chamber drives ion diffusion through the CH, generating an open-circuit voltage (VOC) that corresponds to the Cl concentration in the sweat chamber. A stable device performance is achieved by further integrating a superhydrophilic poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) thin film that prevents ion exchange and hydrogel swelling. The resulting sensor exhibits an ultrahigh sensitivity of 1.7 mV/mM and a fast response time of 7.1 s, with excellent linearity and reversibility in the range from 10 to 100 mM. Integrating the sensor with a microfluidic module along with temperature calibration provides continuous and calibrated, accurate measurements during physical activities. The design concepts for real-time sweat Cl detection can also be applied to monitor the other biomarkers for personalized diagnostics and health monitoring.

Metrics

9 Record Views
4 citations in Web of Science

Details

InCites Highlights

Data related to this publication, from InCites Benchmarking & Analytics tool:

Web of Science research areas
Biophysics
Biotechnology & Applied Microbiology
Chemistry, Analytical
Electrochemistry
Nanoscience & Nanotechnology
Logo image