Tetrodotoxin (TTX) is a potent marine neurotoxin, necessitating sensitive and user-friendly on-site assays. To address long workflows of traditional immunoassays and limited signal amplification in colorimetric microfluidics, we developed a nanozyme-catalyzed colorimetric magnetic microfluidic immunosensor (Nano-CMI). This platform combines an aptamer–antibody sandwich capture format with catalytic amplification via AuNR@Pt@m-SiO₂ (APMS) nanozymes on a magnetically actuated microfluidic chip. Magnetic actuation simplifies sample handling and washing, while APMS catalysis enhances sensitivity and visual readout. The Nano-CMI has been used for the detection of TTX samples ranging from 0.2 to 20 ng/mL with a detection limit of 0.2 ng/mL in 10 min, following the linear equation: y = −31.14ln x + 110.15, and the entire “capture-reaction-detection” workflow can be completed within 1 h. With rapid response, minimal hands-on time, and robust performance, this platform offers a practical, high-sensitivity solution for on-site TTX screening in food safety and customs inspection.

In recent years, the point-of-care testing (POCT) device for nucleic acid detection has received extensive attention. POCT device provides rapid, high sensitivity and accuracy of on-site diagnosis and can quantify the nucleic acid in clinical samples in real time. The integration of microfluidics ensures accurate fluid control, minimizes sample volume, and improves detection efficiency. In addition, POCT devices can conduct multichannel analysis, facilitate continuous monitoring, and provide comprehensive quantitative data. Due to its portability, cost-effectiveness, and ease of use, POCT device represents a promising solution for extensive, reliable, and timely nucleic acid detection in various medical environments. This review summarizes the research and development of nucleic acid detection POCT devices based on microfluidic technology in recent years, and the development trend of the device has prospected.