Optical nanogap antennas as plasmonic biosensors for the detection of miRNA biomarkers
Portela Otaño, Alejandro (Institut Català de Nanociència i Nanotecnologia)
Calvo Lozano, Olalla (Institut Català de Nanociència i Nanotecnologia)
Estévez, M. Carmen (Institut Català de Nanociència i Nanotecnologia)
Medina Escuela, Alfonso (Universidad de Las Palmas de Gran Canaria)
Lechuga, Laura M (Institut Català de Nanociència i Nanotecnologia)

Fecha:	2020
Resumen:	Nanoplasmonic biosensors based on nanogap antenna structures usually demand complex and expensive fabrication processes in order to achieve a good performance and sensitive detection. We here report the fabrication of large-area nanoplasmonic sensor chips based on nanogap antennas by employing a customized, simple and low-cost colloidal lithography process. By precisely controlling the angle for tilted e-beam metal evaporation, an elliptical mask is produced, which defines the total length of the dipole antenna nanostructures while assuring that the plasmonic response is oriented in the same direction along the sensor chip. Large-area sensor chips of nanogap antennas formed by pairs of gold nanodisks separated by gaps with an average size of 11. 6 ± 4. 7 nm are obtained. The optical characterization of the nanogap antenna structures in an attenuated total reflection (ATR) configuration shows a bulk refractive index sensitivity of 422 nm per RIU, which is in agreement with FDTD numerical simulations. The biosensing potential of the cm-sized nanostructured plasmonic sensor chips has been evaluated for the detection of miRNA-210, a relevant biomarker for lung cancer diagnosis, through a DNA/miRNA hybridization assay. A limit of detection (LOD) of 0. 78 nM (5. 1 ng mL) was achieved with no need of further amplification steps, demonstrating the high sensitivity of these plasmonic nanogap antennas for the direct and label-free detection of low molecular weight biomolecules such as miRNAs.
Ayudas:	Ministerio de Ciencia e Innovación TEC2016-78515-R Ministerio de Economía y Competitividad SEV-2017-0706
Derechos:	Tots els drets reservats.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió sotmesa a revisió
Materia:	Attenuated total reflections ; Colloidal lithography ; Label-free detection ; Low molecular weight ; Lung cancer diagnosis ; Optical characterization ; Plasmonic biosensors ; Refractive index sensitivity
Publicado en:	Journal of materials chemistry B, Vol. 8, Issue 19 (May 2020) , p. 4310-4317, ISSN 2050-7518

DOI: 10.1039/d0tb00307g

Preprint 9 p, 587.2 KB

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Documentos de investigación > Documentos de los grupos de investigación de la UAB > Centros y grupos de investigación (producción científica) > Ciencias > Institut Català de Nanociència i Nanotecnologia (ICN2)
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