Amplification-free detection of SARS-CoV-2 using gold nanotriangles functionalized with oligonucleotides

Gold nanotriangles (AuNTs) functionalized with dithiolated oligonucleotides have been employed to develop an amplification-free electrochemical biosensor for SARS-CoV-2 in patient samples. Gold nanotriangles, prepared through a seed-mediated growth method and exhaustively characterized by different...

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Detalles Bibliográficos
Autores: Caño, Rafael del, García-Mendiola, Tania, García-Nieto, Daniel, Álvaro Bruna, Raquel, Luna, Mónica, Alarcón Iniesta, Hernán, Coloma, Rocío, Rodríguez Diaz, Ciro, Milán-Rois, Paula, Castellanos, Milagros, Abreu, Melanie, Cantón, Rafael, Galán, Juan Carlos, Pineda, Teresa, Pariente, Félix, Miranda, Rodolfo, Somoza, Álvaro, Lorenzo, Encarnación
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/269523
Acceso en línea:http://hdl.handle.net/10261/269523
Access Level:acceso abierto
Palabra clave:AuNTs
Biosensors
SARS-CoV-2
Amplification-free detection
Descripción
Sumario:Gold nanotriangles (AuNTs) functionalized with dithiolated oligonucleotides have been employed to develop an amplification-free electrochemical biosensor for SARS-CoV-2 in patient samples. Gold nanotriangles, prepared through a seed-mediated growth method and exhaustively characterized by different techniques, serve as an improved electrochemical platform and for DNA probe immobilization. Azure A is used as an electrochemical indicator of the hybridization event. The biosensor detects either single stranded DNA or RNA sequences of SARS-CoV-2 of different lengths, with a low detection limit of 22.2 fM. In addition, it allows to detect point mutations in SARS-CoV-2 genome with the aim to detect more infective SARS-CoV-2 variants such as Alpha, Beta, Gamma, Delta, and Omicron. Results obtained with the biosensor in nasopharyngeal swab samples from COVID-19 patients show the possibility to clearly discriminate between non-infected and infected patient samples as well as patient samples with different viral load. Furthermore, the results correlate well with those obtained by the gold standard technique RT-qPCR, with the advantage of avoiding the amplification process and the need of sophisticated equipment.