Sensitive and Label-Free Detection of miRNA-145 by Triplex Formation
A. Aviñó, C. S. Huertas, L. M. Lechuga & R. Eritja
Analytical and Bioanalytical Chemistry, 408(3), 2016, 885-93 - DOI: 10.1007/s00216-015-9180-6
Abstract: The development of new strategies for detecting miRNAs has become a crucial step in the diagnostic field. miRNA profiles depend greatly on the sample and the analytical platform employed, leading sometimes to contradictory results. In this work we study the use of modified parallel tail-clamps to detect a miRNA sequence involved in tumor suppression by triplex formation. Thermal denaturing curves and CD measurements have been performed to confirm that parallel clamps carrying 8-aminoguanine form the most stable triplex structures with their target miRNA. The modified tail-clamps have been tested as bioreceptors in a SPR biosensor for the detection of miRNA-145. The detection limit was improved 2.4 times demonstrating that a stable triplex structure is formed between target miRNA and 8-aminoguanine tail-clamp bioreceptor. This new approach is an essential step toward the label-free and reliable detection of miRNA signatures for diagnostic purposes.