Méndez González, DiegoSilva Ibáñez, Pedro PabloValiente Dies, FernandoGómez Calderón, ÓscarMéndez González, Juan LuisLaurenti, MarcoEgatz-Gómez, AnaDíaz García, ElenaRubio Retama, Benito JorgeMelle Hernández, Sonia2023-06-172023-06-172021-03-11Méndez González, D., Silva Ibáñez, P. P., Valiente Dies, F. et al. «Oligonucleotide Sensor Based on Magnetic Capture and Photoligation of Upconverting Nanoparticles in Solid Surfaces». Journal of Colloid and Interface Science, vol. 596, agosto de 2021, pp. 64-74. DOI.org (Crossref), https://doi.org/10.1016/j.jcis.2021.02.093.0021-979710.1016/j.jcis.2021.02.093https://hdl.handle.net/20.500.14352/7942In this work, we present a luminescence platform that can be used as point of care system for determining the presence and concentration of specific oligonucleotide sequences. This sensor exhibited a limit of detection as low as 50 fM by means of: i) the use of single-stranded DNA (ssDNA) functionalized magnetic microparticles that captured and concentrated ssDNA-upconverting nanoparticles (ssDNA-UCNPs) on a solid support, when the target sequence (miR-21-5p DNA-analogue) was in the sample, and ii) a photoligation reaction that covalently linked the ssDNA-UCNPs and the ssDNA magnetic microparticles, allowing stringent washes. The presented sensor showed a similar limit of detection when the assays were conducted in samples containing total miRNA extracted from human serum, demonstrating its suitability for detecting small specific oligonucleotide sequences under real-like conditions. The strategy of combining UCNPs, magnetic microparticles, and photoligation reaction provides new insight into low-cost, rapid, and ultra-sensitive detection of oligonucleotide sequences.engAtribución-NoComercial-SinDerivadas 3.0 Españahttps://creativecommons.org/licenses/by-nc-nd/3.0/es/journal articlehttps://doi.org/10.1016/j.jcis.2021.02.093open access577.113.3539.2:620.1Upconverting nanoparticlesMagnetic microparticlesDNA detectionPhotoligationMagnetic captureMagnetic concentrationBiosensorFísica (Física)Óptica (Física)PartículasDiagnóstico por imagen y medicina nuclearTécnicas de la imagen22 Física2209.19 Óptica Física2208 Nucleónica3204.01 Medicina Nuclear