Compact Digital Immunoassay Platform Integrating ELISA with a Lateral Flow Strip

Area of Science:

• Biotechnology
• Immunodiagnostics
• Point-of-Care Testing

Background:

• Early-stage infection diagnosis demands sensitive, portable, and user-friendly assays for non-laboratory settings.
• Current diagnostic technologies often lack the required sensitivity and ease of use, necessitating skilled personnel.

Purpose of the Study:

• To develop and evaluate the D-strip, a novel Point-of-Care-Testing (PoCT) immunoassay platform.
• To address the limitations of existing assays for on-site infection detection.

Main Methods:

• Development of the D-strip platform, integrating digital enzyme-linked immunoassay (ELISA) with lateral flow assay (LFA) principles.
• Utilizing a sample flow cell similar to conventional LFAs but with enhanced ELISA implementation for high sensitivity.
• Designing for simplicity and minimal user intervention.

Main Results:

• The D-strip achieved a sample-to-result time of 15 minutes.
• Demonstrated a limit of detection (LOD) of 1.7 × 10^3 copies/mL for SARS-CoV-2 antigen.
• Exhibited an LOD 488-fold higher than conventional LFAs, comparable to clinical laboratory tests.

Conclusions:

• The D-strip platform is compact and highly sensitive.
• It shows significant potential as a confirmatory diagnostic assay for use outside clinical laboratories.