Quantitative injection strip platform using water-soluble paper and magnet based on a lateral flow assay

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Assay Development

Background:

• Quantitative analysis in lateral flow immunoassay (LFA) is crucial for accurate concentration measurement.
• Traditional LFA strips can suffer from signal variability due to inconsistent sample volumes.
• Improving the precision of LFA strips is essential for point-of-care diagnostics.

Purpose of the Study:

• To design and evaluate a novel quantitative injection (QI) strip for improved LFA accuracy.
• To address the challenge of variable sample volumes in conventional LFA devices.
• To enhance the reliability of strip-based quantitative analysis.

Main Methods:

• Modification of LFA strip structure using water-soluble paper and a magnet to ensure a consistent unit volume injection.
• Incorporation of a physical separation mechanism for the gold conjugate pad and nitrocellulose membrane at an optimized time.
• Comparative analysis of detection signal consistency and deviation between QI strips and standard LFA strips across varying sample volumes.

Main Results:

• The QI strip successfully maintained consistent detection signals regardless of injected sample volume.
• Standard LFA strips showed increased detection signals with larger sample volumes.
• The QI strip exhibited an 11-fold reduction in data deviation compared to standard LFA strips.
• The integrated separation function was identified as the key factor for improved performance.

Conclusions:

• The QI strip offers a user-friendly and equipment-free solution for precise quantitative analysis in LFAs.
• QI strips demonstrate superior suitability for quantitative applications over traditional LFA strips.
• This technology holds potential for advancing user-friendly point-of-care testing (POCT) and strip-based diagnostics.