Mitigating hook effect in one-step quantitative sandwich lateral flow assay by timed conjugate release.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Biosensor Technology

Background:

• Sandwich lateral flow assays (LFAs) are widely used paper-based biosensors known for speed and low cost.
• A critical limitation of conventional LFAs is the high-dose hook effect, leading to false negatives at high analyte concentrations.
• Mitigating the hook effect is crucial for improving the reliability and diagnostic utility of LFAs.

Purpose of the Study:

• To develop a novel strategy for automatic timed detection antibody release in sandwich LFAs.
• To mitigate the hook effect in LFAs without introducing additional manual steps.
• To enhance the dynamic detection range of LFAs while maintaining sensitivity.

Main Methods:

• Introduced an intermediate pad treated with saturated sucrose solution to regulate reagent flow.
• Delayed the reaction kinetics between detection antibodies and analytes within the LFA.
• Utilized C-reactive protein (CRP) as a model analyte to validate the strategy.

Main Results:

• The novel timed release strategy significantly widened the detection range by 10-fold compared to conventional LFAs.
• The limit of detection remained comparable to traditional LFAs, indicating no loss in sensitivity.
• The method demonstrated effective mitigation of the hook effect in sandwich LFAs.

Conclusions:

• The automatic timed detection antibody release strategy effectively addresses the hook effect in sandwich LFAs.
• This approach offers a one-step, cost-effective enhancement to LFA technology.
• The developed method broadens the applicability of LFAs for detecting high-concentration analytes.