Low cost 3D microfluidic chips for multiplex protein detection based on photonic crystal beads

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Materials Science

Background:

• Point-of-care testing (POCT) is crucial for clinical, environmental, and biomedical applications.
• Multiplex bioassays require sensitive and convenient biomarker detection methods.
• Photonic crystal beads (PCBs) offer self-coding capabilities for bioassay integration.

Purpose of the Study:

• To develop a cost-effective, mass-producible 3D microfluidic chip for multiplex bioassays using PCBs.
• To evaluate the chip's performance in terms of sensitivity, background reduction, and multiplexing capability.

Main Methods:

• Fabrication of a 3D microfluidic chip using polyethylene terephthalate, polymethyl methacrylate, a Ni square mesh grid, and double-sided tape.
• Immobilization of probes onto PCBs for target molecule capture in a flow-through manner.
• Assessment of chip performance using anti-human alpha fetoprotein (AFP) and simultaneous detection of multiple biomarkers.

Main Results:

• The 3D microfluidic chip required less washing and exhibited reduced background compared to flow-over designs.
• The limit of detection (LOD) for anti-human AFP was 18.92 ng/mL, suitable for clinical use.
• Simultaneous detection of human immunoglobulin G, carcinoembryonic antigen, and AFP was demonstrated.

Conclusions:

• The developed 3D microfluidic chip based on PCBs is a promising platform for sensitive and multiplexed point-of-care testing.
• The low-cost, mass-producible design facilitates broad applications in clinical diagnostics and biomedical research.