A centrifugal microfluidic chip with its companion device for automatic point-of-care nanozyme ELISA lateral flow immunoassay based on optoelectronic sensing

Influenza viruses spread rapidly, seriously threatening human health, for example, causing serious and even deadly respiratory diseases, and weakening the global economy. Influenza virus detection methods include molecular detection and immunoassay, and compared to molecular detection, the traditional lateral flow immunoassay is widely used in point-of-care testing (POCT) due to its advantages of fast detection, low cost and ease of use. However, these assays are often limited by trivial operational procedure, specialized skills, and long detection time. To address these challenges and enable rapid and highly sensitive pathogen detection, we developed a centrifugal analyzing platform and a centrifugal microfluidic chip integrated with a nanozyme lateral flow strip for automated detection of H1N1 viral antigens. The signal amplification using nanozyme-based enzyme-linked immunosorbent assay (ELISA) significantly improves the sensitivity and shortens the assay time. A peak searching algorithm was utilized to semi-quantitatively analyze the detection and control lines on the lateral flow strip of the nanozyme, which showed a 2.5-fold increase in the lower limit of detection compared to the eye-observation-based assay. In the automated detection system, the centrifugal microfluidic chip sequentially delivers the sample and color development solution to the lateral flow strip, facilitating fully automated operation and minimizing the risk of manual errors. Experimental results show that the manual operation takes only 1 minute, and the total testing time is only 16 minutes. This study highlights a multifunctional platform for automated nanozyme-based ELISA assay, offering broad applicability in medical diagnostics, environmental monitoring, and food safety testing.