A novel laminar flow-based hierarchical microfluidic (LF-HM) chip for multiplex detection without cross-talk

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Microfluidics

Background:

• Microfluidic devices offer potential for cost-effective, point-of-care diagnostics with reduced reagent use.
• Assay cross-talk in multiplexed microfluidic systems hinders the integration of incompatible detection methods.

Purpose of the Study:

• To develop a novel microfluidic chip addressing cross-talk challenges in multiplexed diagnostics.
• To enable reliable, integrated point-of-care testing by isolating incompatible assays.

Main Methods:

• A laminar flow-based hierarchical microfluidic (LF-HM) chip was designed and simulated using finite element analysis.
• Experimental validation involved characterizing laminar flow stability, determining optimal operating temperature, and assessing cross-talk elimination.
• The chip's performance was evaluated by integrating rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) assays.

Main Results:

• Finite element simulations confirmed the chip's fluid handling capabilities and minimal flow disturbance.
• Stable laminar flow was achieved, with an optimal operating temperature range of 15-26°C identified to minimize diffusion.
• Complete cross-talk elimination was demonstrated, with integrated RF and ACPA assays showing excellent analytical agreement and strong correlation with reference methods in clinical validation.

Conclusions:

• The LF-HM chip provides a robust and generalizable solution for cross-talk-free multiplexed diagnostics.
• This technology has broad potential for advancing point-of-care diagnostic devices, overcoming limitations of previous integrated assay designs.