Highly Stretchable and Strain-Insensitive Fiber-Based Wearable Electrochemical Biosensor to Monitor Glucose in the Sweat

TLDR

Fiber‑shaped wearable sensors are critical for next‑generation smart textiles, yet prior work focused mainly on physical parameters; recent interest has shifted to non‑invasive biochemical monitoring such as sweat glucose to meet diabetic patients’ clinical needs. This study aims to develop an enzyme‑based, highly stretchable, strain‑insensitive electrochemical sensor for real‑time sweat glucose monitoring. The authors fabricated an elastic gold fiber three‑electrode platform, functionalizing the working electrode with Prussian blue and glucose oxidase, using Ag/AgCl as reference and a nonmodified gold counter, achieving high conductivity and strain resilience. The resulting textile biosensor exhibited a 0–500 μM linear range, 11.7 μA mM⁻¹ cm⁻² sensitivity, and maintained performance under 200 % strain, demonstrating suitability for real‑world wearable diagnostics.

Abstract

Development of high-performance fiber-shaped wearable sensors is of great significance for next-generation smart textiles for real-time and out-of-clinic health monitoring. The previous focus has been mainly on monitoring physical parameters such as pressure and strains associated with human activities. Development of an enzyme-based non-invasive wearable electrochemical sensor to monitor biochemical vital signs of health such as the glucose level in sweat has attracted increasing attention recently, due to the unmet clinical needs for the diabetic patients. To achieve this, the key challenge lies in the design of a highly stretchable fiber with high conductivity, facile enzyme immobilization, and strain-insensitive properties. Herein, we demonstrate an elastic gold fiber-based three-electrode electrochemical platform that can meet the aforementioned criteria toward wearable textile glucose biosensing. The gold fiber could be functionalized with Prussian blue and glucose oxidase to obtain the working electrode and modified by Ag/AgCl to serve as the reference electrode; and the nonmodified gold fiber could serve as the counter electrode. The as-fabricated textile glucose biosensors achieved a linear range of 0–500 μM and a sensitivity of 11.7 μA mM–1 cm–2. Importantly, such sensing performance could be maintained even under a large strain of 200%, indicating the potential applications in real-world wearable biochemical diagnostics from human sweat.