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. (C) 2013 Elsevier B.V. All rights reserved.