Plastic ELISA-on-a-chip based on sequential cross-flow chromatography.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Point-of-Care Diagnostics

Background:

• Enzyme-linked immunosorbent assays (ELISA) are crucial for detecting biomarkers like cardiac troponin I (cTnI).
• Conventional ELISA methods can be time-consuming and require laboratory infrastructure.
• There is a need for rapid, sensitive, and portable diagnostic tools for cardiac markers.

Purpose of the Study:

• To develop and evaluate an ELISA-on-a-chip device for quantifying cardiac troponin I (cTnI).
• To integrate ELISA principles into a microfluidic platform for point-of-care applications.
• To assess the analytical performance and diagnostic accuracy of the developed chip.

Main Methods:

• A microfluidic chip was designed with orthogonal channels for cross-flow chromatography.
• An immunostrip incorporating horseradish peroxidase (HRP)-labeled antibodies for cTnI detection was integrated into the chip.
• Enzyme substrate was introduced, and colorimetric detection was performed using a digital camera-based system.

Main Results:

• The ELISA-on-a-chip achieved a detection limit of approximately 0.1 ng/mL for cTnI.
• A quantification limit of 0.25 ng/mL was established for the assay.
• The chip demonstrated performance correlating with a reference system (Beckman Coulter Access) within a 2.5-fold discrepancy.

Conclusions:

• The developed ELISA-on-a-chip is a promising tool for rapid and sensitive cTnI detection.
• The microfluidic design and enzyme-based detection enable efficient immunoassays.
• This platform holds potential for point-of-care cardiac marker diagnostics.