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A Low-Cost, High-Performance System for Fluorescence Lateral Flow Assays
Song Diagnostic Research LLC, 1 Megans Lane, Woodside, CA 94062, USA
These authors contributed equally to this work.
* Author to whom correspondence should be addressed.
Received: 6 September 2013; in revised form: 9 October 2013 / Accepted: 10 October 2013 / Published: 21 October 2013
Abstract: We demonstrate a fluorescence lateral flow system that has excellent sensitivity and wide dynamic range. The illumination system utilizes an LED, plastic lenses and plastic and colored glass filters for the excitation and emission light. Images are collected on an iPhone 4. Several fluorescent dyes with long Stokes shifts were evaluated for their signal and nonspecific binding in lateral flow. A wide range of values for the ratio of signal to nonspecific binding was found, from 50 for R-phycoerythrin (R-PE) to 0.15 for Brilliant Violet 605. The long Stokes shift of R-PE allowed the use of inexpensive plastic filters rather than costly interference filters to block the LED light. Fluorescence detection with R-PE and absorbance detection with colloidal gold were directly compared in lateral flow using biotinylated bovine serum albumen (BSA) as the analyte. Fluorescence provided linear data over a range of 0.4–4,000 ng/mL with a 1,000-fold signal change while colloidal gold provided non-linear data over a range of 16–4,000 ng/mL with a 10-fold signal change. A comparison using human chorionic gonadotropin (hCG) as the analyte showed a similar advantage in the fluorescent system. We believe our inexpensive yet high-performance platform will be useful for providing quantitative and sensitive detection in a point-of-care setting.
Keywords: fluorescence lateral flow immunoassay; phycoerythrin; biotinylated BSA; hCG
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MDPI and ACS Style
Lee, L.G.; Nordman, E.S.; Johnson, M.D.; Oldham, M.F. A Low-Cost, High-Performance System for Fluorescence Lateral Flow Assays. Biosensors 2013, 3, 360-373.
Lee LG, Nordman ES, Johnson MD, Oldham MF. A Low-Cost, High-Performance System for Fluorescence Lateral Flow Assays. Biosensors. 2013; 3(4):360-373.
Lee, Linda G.; Nordman, Eric S.; Johnson, Martin D.; Oldham, Mark F. 2013. "A Low-Cost, High-Performance System for Fluorescence Lateral Flow Assays." Biosensors 3, no. 4: 360-373.