Abstract
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.
Keywords: Amplification-free detection; AuNTs; Biosensor; SARS-CoV-2.
【저자키워드】 SARS-CoV-2, biosensor, Amplification-Free Detection, AuNTs, 【초록키워드】 SARS-CoV-2, equipment, SARS-CoV-2 variant, Delta, omicron, biosensor, Nasopharyngeal swab, amplification, DNA, RT-qPCR, Viral load, SARS-CoV-2 genome, Patient, Gamma, gold, point mutations, Alpha, Beta, platform, COVID-19 patients, Nasopharyngeal swab samples, Detection limit, Point mutation, COVID-19 patient, growth, gold standard, nasopharyngeal swab sample, oligonucleotide, RNA sequences, infective, probe, RNA sequence, non-infected, Result, detect, develop, addition, characterized, Azure, 【제목키워드】 SARS-CoV-2, oligonucleotide,