Contact lens-based lysozyme detection in tear using a mobile sensor. Issue 8 (30th March 2020)

• Record Type: Journal Article
• Authors: Ballard, Zachary; Bazargan, Sarah; Jung, Diane; Sathianathan, Shyama; Clemens, Ashley; Shir, Daniel; Al-Hashimi, Saba; Ozcan, Aydogan
• Is Part Of: Lab on a chip. Volume 20:Issue 8(2020)
• Page Start: 1493
• Page End: 1502
• Publication Date: 2020-03-30
• Subjects: Miniature electronic equipment -- Periodicals; Combinatorial chemistry -- Periodicals; Biotechnology -- Periodicals; 543.0813
• DOI: 10.1039/c9lc01039d
• Languages: English
• ISSNs: 1473-0197

Abstract

Abstract : A rapid and cost-effective method for monitoring proteins in tear-fluid is reported, which enables biomarker monitoring using contact lenses toward personalized mobile-health applications. Abstract : We report a method for sensing analytes in tear-fluid using commercial contact lenses (CLs) as sample collectors for subsequent analysis with a cost-effective and field-portable reader. In this study we quantify lysozyme, the most prevalent protein in tear fluid, non-specifically bound to CLs worn by human participants. Our mobile reader uses time-lapse imaging to capture an increasing fluorescent signal in a standard well-plate, the rate-of-change of which is used to indirectly infer lysozyme concentration through the use of a standard curve. We empirically determined the best-suited CL material for our sampling procedure and assay, and subsequently monitored the lysozyme levels of nine healthy human participants over a two-week period. Of these participants who were regular CL wearers (6 out of 9), we observed an increase in lysozyme levels from 6.89 ± 2.02 μg mL −1 to 10.72 ± 3.22 μg mL −1 (mean ± SD) when inducing an instance of digital eye-strain by asking them to play a game on their mobile-phones during the CL wear-duration. We also observed a lower mean lysozyme concentration (2.43 ± 1.66 μg mL −1 ) in a patient cohort with dry eye disease (DED) as compared to the average monitoring level of healthy (no DED) human participants (6.89 ± 2.02 μg mL −1 ). Taken together, this study demonstrates tear-fluid analysis with simple and non-invasive sampling steps along with a rapid, easy-to-use, and cost-effective measurement system, ultimately indicating physiological differences in human participants. We believe this method could be used in future tear-fluid studies, even supporting multiplexed detection of a panel of tear biomarkers toward improved diagnostics and prognostics as well as personalized mobile-health applications.