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Converting colour to length based on the coffee-ring effect for quantitative immunoassays using a ruler as readout
Dagan Zhang1, Bingbing Gao, Yangtian Chen
1State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China. liuh@seu.edu.cn.
Lab on a Chip
|December 14, 2017
Summary
This study introduces a simple method to quantify analytes using a ruler by converting enzyme-linked immunosorbent assay (ELISA) color results into length measurements via the coffee-ring effect. This technique is promising for point-of-care biomarker detection in resource-limited settings.
Area of Science:
- Biomarker Detection
- Assay Development
- Microfluidics
Background:
- Enzyme-linked immunosorbent assay (ELISA) is a common diagnostic technique.
- Colorimetric readouts in ELISA often require specialized equipment.
- Quantitative detection in resource-limited settings remains a challenge.
Purpose of the Study:
- To develop a simple, ruler-based method for quantitative analyte detection.
- To convert colorimetric ELISA results into length measurements.
- To explore the coffee-ring effect for diagnostic applications.
Main Methods:
- Utilized the coffee-ring effect to transform colorimetric signals into measurable lengths.
- Investigated the impact of paper strip design (shape, lamination) on assay performance.
- Demonstrated the method by quantifying human IgG concentrations.
Main Results:
- A correlation was established between the width of colored stains and analyte concentration.
- The developed method allows for simple, ruler-based quantitative analysis.
- Paper strip parameters were found to influence test outcome.
Conclusions:
- The coffee-ring effect offers a novel approach for quantitative ELISA readout.
- This method enables simple, ruler-based biomarker quantification.
- The technique shows potential for point-of-care diagnostics in resource-limited environments.
