Affimer sandwich probes for stable and robust lateral flow assaying

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biotechnology

Background:

• Lateral flow assays (LFAs) are crucial for rapid, on-site diagnostics.
• Conventional LFAs often use antibodies, which have limited thermal stability, impacting assay performance and shelf life.
• Developing more stable recognition molecules is essential for improving LFA robustness.

Purpose of the Study:

• To develop a thermally stable and robust lateral flow assay (LFA) using affimers as recognition molecules.
• To replace conventional antibodies with peptide-based affimers for enhanced stability and shelf life.
• To demonstrate the efficacy of affimer-based LFAs for detecting biomarkers in complex samples.

Main Methods:

• Utilized peptide-based affimers as recognition elements in LFAs, replacing traditional antibodies.
• Employed a pair of affimer probes with dual capture and reporting functionality for interleukin-8 (IL8) detection.
• Developed a system where affimers immobilized on the test zone capture IL8-affimer-MB complexes, enabling visual detection.

Main Results:

• Achieved sensitive visual detection of IL8 at ng/mL levels in buffer and human plasma within 20 minutes.
• Demonstrated significantly improved stability of affimer-incorporated LFAs compared to antibody-based LFAs, even at 4°C.
• Validated the assay's performance using a model system with IL8 biomarker in complex matrices.

Conclusions:

• Affimer-based LFAs offer a stable and reliable alternative to antibody-based assays for biomarker detection.
• The developed affimer-LFA technology enhances assay shelf life and performance without requiring cold storage.
• This approach presents a promising solution for on-site diagnostics, particularly in resource-limited settings.