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Microfluidic Paper-Based Analytical Devices for Colorimetric Detection of Lactoferrin
Hiroko Kudo1, Kento Maejima1, Yuki Hiruta1
1Department of Applied Chemistry, Keio University, Yokohama, Kanagawa, Japan.
SLAS Technology
|October 30, 2019
Summary
This study presents a new colorimetric method for detecting lactoferrin, a disease biomarker, using microfluidic paper-based analytical devices (µPADs). The developed devices offer a simple, antibody-free, and cost-effective point-of-care testing solution.
Area of Science:
- Analytical Chemistry
- Biomarker Detection
- Point-of-Care Testing
Background:
- Lactoferrin is a key glycoprotein biomarker in human body fluids, indicating various disease states.
- Current diagnostic methods for lactoferrin lack point-of-care (POCT) accessibility.
- Microfluidic paper-based analytical devices (µPADs) offer a promising platform for inexpensive, simple, and disposable POCT.
Purpose of the Study:
- To develop a novel colorimetric sensing approach for quantitative lactoferrin analysis.
- To create user-friendly, lab-equipment-free POCT devices for lactoferrin detection.
- To demonstrate the efficacy of µPADs for lactoferrin quantification.
Main Methods:
- A colorimetric detection mechanism utilizing the high affinity of lactoferrin for ferric ions (Fe³⁺).
- Encapsulation of a 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP)-Fe³⁺ complex into poly(styrene-block-vinylpyrrolidone) particles for paper immobilization.
- Development of both color intensity-based paper well plates and distance readout-based µPADs.
Main Results:
- The encapsulated 5-Br-PADAP-Fe³⁺ complex exhibited a concentration-dependent color change in response to lactoferrin.
- Color intensity-based devices achieved a limit of detection of 110 µg/mL using smartphone-based color readout.
- Distance readout-based µPADs showed measurable changes in colored section length correlating with lactoferrin concentration.
Conclusions:
- Successfully developed both colorimetric intensity-based paper wells and distance-based µPADs for lactoferrin detection.
- Demonstrated a user-friendly, cost-effective colorimetric analysis platform for lactoferrin POCT.
- The developed µPADs eliminate the need for laboratory equipment and expensive antibodies.
