Visual detection of microRNA with lateral flow nucleic acid biosensor.

We report a DNA-gold nanoparticle (DNA-GNP) based lateral flow nucleic acid biosensor for visual detection of microRNA (miRNA)-215 in aqueous solutions and biological samples with low-cost and short analysis time. Sandwich-type hybridization reactions among GNP-labeled DNA probe, miRNA-215 and biotin-modified DNA probes were performed on the lateral flow device. The accumulation of GNPs on the test zone of the biosensor enables the visual detection of miRNA-215. After systematic optimization, the biosensor was able to detect a minimum concentration of 60 pM miRNA-215. The biosensor was applied to detect miRNA-215 from A549 cell lysate directly without complex sample treatment, and the detection limit of 0.148 million cells was obtained. This study provides a simple, rapid, specific and low-cost approach for miRNA detection in aqueous solutions and biological samples, showing great promise for clinical application and biomedical diagnosis in some malignant diseases.