Torrente Rodríguez, Rebeca MagnoliaCampuzano Ruiz, SusanaRuiz Valdepeñas Montiel, VíctorMontoya Miñano, Juan JoséPingarrón Carrazón, José Manuel2024-01-292024-01-292016Torrente-Rodríguez, R.M., et al., Biosensors and Bioelectronics (2016), http://dx.doi.org/10.1016/j. bios.2016.07.003iTorrente-Rodríguez, R. M., et al. «Sensitive Electrochemical Determination of miRNAs Based on a Sandwich Assay onto Magnetic Microcarriers and Hybridization Chain Reaction Amplification». Biosensors and Bioelectronics, vol. 86, diciembre de 2016, pp. 516-21. https://doi.org/10.1016/j.bios.2016.07.003.0956-566310.1016/j.bios.2016.07.003https://hdl.handle.net/20.500.14352/96114A novel electrochemical approach for determination of miRNAs involving a sandwich hybridization assay onto streptavidin-magnetic beads (Strep-MBs), hybridization chain reaction (HCR) amplification and amperometric detection at disposable screen-printed carbon electrodes is reported. Using miRNA-21 as the target analyte, a dynamic linear range from 0.2 to 5.0 nM with a 60 pM (1.5 fmol in 25 μL) detection limit was obtained. The achieved sensitivity is 24-fold higher than a non-HCR amplification approach involving conventional sandwich type assay onto MBs. Moreover, the whole assay time lasted 1 h 45 min which is remarkably shorter than other reported methodologies. The methodology exhibited full selectivity against other non-complementary miRNAs as well as an acceptable discrimination between homologous miRNA family members. The applicability of this novel approach was demonstrated by determining mature miRNA-21 in total RNA (RNAt) extracted from tumor cells and human tissues.engjournal articlehttps://doi.org/10.1016/j.bios.2016.07.003restricted access543MiRNA-21Magnetic beadsHybridization chain reactionSPCEsTumor cellHuman tissuesQuímica analítica (Química)2301 Química Analítica