Pressed Lateral Flow Assay Strips for Flow Delay-Induced Signal Enhancement in Lateral Flow Assay Strips

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Point-of-Care Diagnostics

Background:

• Lateral flow assays (LFAs) are widely used for rapid diagnostics.
• Improving the sensitivity and reliability of LFAs is crucial for accurate disease detection.
• Current LFAs can sometimes produce ambiguous results due to limited reaction times.

Purpose of the Study:

• To investigate a novel method for enhancing signal intensity in LFAs.
• To determine if applying pressure to LFA strips can improve detection limits.
• To validate this technique on both model analytes and commercial diagnostic kits.

Main Methods:

• Developing a pressed LFA (pLFA) strip technique by applying pressure to the top of the strip.
• Detecting C-reactive protein (CRP) using pLFA strips in buffer and serum.
• Testing the pLFA method on commercially available COVID-19 antigen test strips.
• Quantifying signal enhancement and changes in the limit of detection.

Main Results:

• Pressing LFA strips significantly increased signal intensity.
• The limit of detection for CRP was lowered using the pLFA method.
• Signal enhancement was observed in commercial COVID-19 antigen test strips.
• Maximum signal intensity increase of approximately two-fold was achieved for COVID-19 LFAs.

Conclusions:

• The pressed LFA (pLFA) technique effectively enhances signal intensity by reducing flow rate.
• This method improves detection limits and reduces the likelihood of false-negative results.
• pLFA technology offers a simple, low-cost approach to enhance existing LFA diagnostic kits.