Switching from Multiplex to Multimodal Colorimetric Lateral Flow Immunosensor.

Area of Science:

• Biomedical Engineering
• Immunology
• Diagnostics

Background:

• Multiplex lateral flow immunoassays (LFIA) are crucial for point-of-care testing, detecting multiple targets simultaneously.
• The need for multitargeting diagnostics drives the development of more informative single tests.

Purpose of the Study:

• To upgrade standard multiplex LFIA to multimodal capacity using three novel strategies.
• To demonstrate the application of these strategies for the differential diagnosis of Human Immunodeficiency Virus (HIV) infection.

Main Methods:

• Developed a two-parameter LFIA (x²LFIA) utilizing color encoding within a single reactive band.
• Employed sequential alignment of reactive zones and gold nanoparticles/nanostars for differential visualization.
• Designed three immunosensor formats, evaluating bioreagent placement (capturing vs. detection ligand).

Main Results:

• The x²LFIA successfully provided information on HIV serotype and infection stage in a single test.
• The configuration using HIV-specific antigens as capturing agents and labeled secondary bioligands as probes yielded higher detectability.
• Different bioreagent placements significantly impacted x²LFIA performance.

Conclusions:

• The developed x²LFIA represents a significant advancement in multimodal diagnostic capacity.
• This technology enhances the informativeness of single-device diagnostics for complex diseases like HIV.
• Optimized immunosensor design is critical for maximizing the performance of advanced LFIA platforms.