Cord-Based Microfluidic Chips as A Platform for ELISA and Glucose Assays

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Assay Development

Background:

• Microfluidic devices offer miniaturized platforms for biochemical assays.
• Enzyme-linked immunosorbent assays (ELISAs) are widely used for detecting antibodies and antigens.
• Glucose assays are crucial for diagnosing and monitoring metabolic conditions.

Purpose of the Study:

• To develop and apply microfluidic cord-based analytical devices (µCADs) for quantitative detection.
• To adapt µCADs for two distinct enzyme-linked immunosorbent assays (ELISAs) and a glucose assay.
• To establish the analytical performance and correlation of µCADs with established detection methods.

Main Methods:

• Antibodies (biotinylated goat anti-mouse IgG, rabbit IgG) and glucose were detected using µCADs.
• ELISAs involved antibody spotting, washing, secondary antibody incubation (Strep-ALP or ALP-conjugated), and colorimetric substrate addition.
• Glucose assay utilized glucose oxidase (GOx), horseradish peroxidase (HRP), and potassium iodide (KI) for colorimetric detection via capillary action.

Main Results:

• ELISAs demonstrated quantitative detection of antibodies, with specific linear ranges and L50 values reported for each assay.
• The first ELISA showed a linear detection range for Strep-ALP from 2.50 × 10⁻⁴–1.75 × 10⁻³ mg/mL.
• The glucose assay correlated yellow inverse intensity with glucose concentration, showing good performance in artificial urine samples.

Conclusions:

• Microfluidic cord-based analytical devices (µCADs) are effective for quantitative antibody and glucose detection.
• The developed µCADs offer a versatile and sensitive platform for biochemical assays, including ELISAs and glucose monitoring.
• These devices show potential for accessible and rapid diagnostic applications in various settings.