A Self-Contained Chemiluminescent Lateral Flow Assay for Point-of-Care Testing

Immunoassays whose readouts rely on chemiluminescence are increasingly useful for a broad range of analytical applications, but they are rarely made into point-of-care (POC) format because of the complex reagents required (some reagents have to be stored in low temperatures, and some reagents have to be freshly made right before the assay). This study reports a self-contained chemiluminescent lateral flow assay (CLFA), which prestores all necessary reagents. This CLFA contains three parts: the normal lateral flow assay (LFA) strip, the chemiluminescence substrate pad, and the polycarbonate (PC) holder. On the LFA strip, we simultaneously labeled horseradish peroxidase (HRP) and antibody on the gold nanoparticles (AuNPs) for the conjugate pad. For the substrate pad, we used sodium perborate as the oxidant and lyophilized the chemiluminescence substrate on the glass fiber, which allows long-term storage. After the transfer of substrate from the substrate pad to the nitrocellulose (NC) membrane, we captured the chemiluminescence signal for the quantification of the targets. The HRP on the AuNPs can amplify the chemiluminescence signal efficiently. We used this CLFA system to detect both macromolecules and small molecules successfully. This self-contained and easily processable device is exceedingly appropriate for rapid detection and is a convenient platform for POC testing.