Microfluidic contact lens for continuous monitoring of ocular oxidative stress
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Oxidative stress-induced ocular dysfunctions are a significant global health concern. Glutathione (GSH), an abundant antioxidant in tears, can serve as an index for oxidative stress (OS). A coumarin-based fluorescent probe named CCAE was synthesized for GSH monitoring, functioning through structural changes via Michael's addition with GSH and elimination by H2O2, which restores the conjugation structure to assess the severity of OS-induced ocular diseases. CCAE demonstrated a high sensitivity with a detection limit (LOD) of 0.12 mM and reversibility for 15 cycles. A wearable contact lens sensor was developed featuring a microfluidic lens patterned with a 365 nm pulsed laser, requiring 6 μL of tears. CCAE was encapsulated in citric acid-crosslinked poly(vinyl alcohol) film and embedded in poly((hydroxyethyl)methacrylate-co-ethylene glycol)/polyvinylpyrrolidone (poly(HEMA-co-EG)/PVP) lenses. A customized smartphone readout device enabled quantitative GSH readings for point-of-care applications. Tested on an ex vivo porcine anterior eye model, the sensor achieved an LOD of 0.204 mM, within a detection range of 0.62–1.17 mM and 0.13–0.73 mM under mild and severe OS conditions respectively. The sensors maintained operational stability for 2 days and storage stability for 1 week. This reversible GSH contact lens sensor offers a unique platform for diagnosing and monitoring OS-related ocular conditions at point-of-care settings.
Date Issued
2025-07-15
Date Acceptance
2025-03-28
Citation
Biosensors and Bioelectronics, 2025, 280
ISSN
0956-5663
Publisher
Elsevier BV
Journal / Book Title
Biosensors and Bioelectronics
Volume
280
Copyright Statement
© 2025 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/40187150
PII: S0956-5663(25)00301-X
Subjects
Dry eye disease
Medical diagnostics
Ocular sensors
Oxidative stress conditions
Point-of-care diagnosis
Smartphone readout device
Publication Status
Published
Coverage Spatial
England
Article Number
117427
Date Publish Online
2025-03-29