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Hussain et al. Soft Sci. 2025, 5, 21 Soft Science
DOI: 10.20517/ss.2025.02

Research Article Open Access

Smart wearable photonic array biosensor for human

sweat analysis

Saddam Hussain, Qasem Ramadan, Mohammed Zourob *
Department of Chemistry, College of Science, Alfaisal University, Riyadh, Al-Maather 11533, Saudi Arabia.

* Correspondence to: Prof. Mohammed Zourob, Department of Chemistry, College of Science, Alfaisal University, Al Zahrawi
Street, Riyadh, Al-Maather 11533, Saudi Arabia. E-mail: mzourob@alfaisal.edu

How to cite this article: Hussain, S.; Ramadan, Q.; Zourob, M. Smart wearable photonic array biosensor for human sweat
analysis. Soft Sci. 2025, 5, 21. https://dx.doi.org/10.20517/ss.2025.02

Received: 11 Jan 2025 First Decision: 6 Feb 2025 Revised: 11 Feb 2025 Accepted: 27 Feb 2025 Published: 27 Apr 2025

Academic Editors: Carlo Massaroni, Roozbeh Ghaffari, Nae-Eung Lee Copy Editor: Pei-Yun Wang Production Editor: Pei-Yun
Wang

Abstract
Cholesteric liquid crystal networks (CLCNs) intertwined with interpenetrating polymer network (IPN) hydrogels
have emerged as a promising platform for the development of optical photonic sensors. However, the integration of
a multiplex biosensor within a flexible substrate for real-time human sweat analysis remains a significant challenge.
Herein, we present a novel flexible CLCN-IPN-based sensor array, embedded within a soft wearable microfluidic
patch, designed for the continuous monitoring of human sweat. This innovative biosensor allows optical detection
of glucose, urea, and lactate with impressive limits of detection: 0.31 mM for glucose, 0.273 mM for urea, and
3.11 mM for lactate. The wearable array biosensor enables real-time analysis of sweat, offering results that can be
interpreted with the naked eye, eliminating the need for complex instruments. This approach to epidermal health
monitoring has the potential to inspire new advancements in wearable sensor devices, contributing to the future of
smart healthcare applications.

Keywords: Smart photonic structures, soft wearable patch, optical sweat monitoring, non-invasive diagnostics,
multiplex biosensing platform

INTRODUCTION
Sweat has been recognized as a health indicator since ancient times, with early physicians observing changes
[1,2]
in sweat odor, color, and quantity during illness and physical exertion . For example, Hippocrates, the

© The Author(s) 2025. Open Access This article is licensed under a Creative Commons Attribution 4.0
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