Preprogrammed, parallel on-chip immunoassay using system-level capillarity control

Area of Science:

• Biochemistry
• Microfluidics
• Assay Development

Background:

• Conventional enzyme-linked immunosorbent assays (ELISA) are time-consuming and labor-intensive due to manual multiwell plate processing.
• There is a need for automated, efficient, and cost-effective immunoassay platforms, especially for point-of-care settings.

Purpose of the Study:

• To develop and validate a capillarity-driven on-chip immunoassay system.
• To demonstrate reduced time, labor, and pipetting steps compared to traditional ELISA.
• To achieve sensitive quantification of specific biomarkers using the microfluidic device.

Main Methods:

• Design and fabrication of a microfluidic device with integrated multiwells and detection channels.
• Utilizing passive, capillarity-driven fluid transport for sample and reagent manipulation.
• Performing multiplexed immunoassays for C-reactive protein and suppressor of tumorigenicity 2 quantification.

Main Results:

• The on-chip immunoassay successfully quantified C-reactive protein and suppressor of tumorigenicity 2 with low detection limits (8 pM and 90 pM, respectively).
• The assay completed within 30 minutes, significantly reducing processing time.
• The number of pipetting steps was reduced approximately fivefold compared to conventional multiwell plate assays.

Conclusions:

• The capillarity-driven on-chip immunoassay offers a time- and labor-saving alternative to traditional ELISA.
• This microfluidic platform is suitable for sophisticated, parallel biochemical processing in resource-limited point-of-care environments.
• The developed device demonstrates the potential for efficient and automated biomarker quantification.