Impedimetric and Amperometric Genosensors for the Highly Sensitive Quantification of SARS-CoV-2 Nucleic Acid using an Avidin-functionalized Multi-walled Carbon Nanotubes Biocapture Platform.

MICHAEL LÓPEZMUJICA; ALEJANDRO TAMBORELLI; ANDRÉS CASTELLARO, DANILO BARCUDI, JOSÉ BOCCO; MARÍA D. RUBIANES, MARCELA C. RODRÍGUEZ; HÉCTOR A. SAKA, JOSÉ L. BOCCO*; PABLO R. DALMASSO*; GUSTAVO A. RIVAS*

Biosensors and Bioelectronics: X

Elsevier Ltd

Año: 2022 vol. 12

e report two novel genosensors for the quantification of SARS-CoV-2 nucleic acid using glassy carbon electrodes modified with a biocapture nanoplatform made of multi-walled carbon nanotubes (MWCNTs) non-covalently functionalized with avidin (Av) as a support of the biotinylated-DNA probes. One of the genosensors was based on impedimetric transduction offering a non-labelled and non-amplified detection of SARS-CoV-2 nucleic acid through the increment of [Fe(CN)6]3-/4- charge transfer resistance. This biosensor presented an excellent analytical performance, with a linear range of 1.0 × 10−18 M - 1.0 × 10−11 M, a sensitivity of (5.8 ± 0.6) x 102 Ω M−1 (r2 = 0.994), detection and quantification limits of 0.33 aM and 1.0 aM, respectively; and reproducibilities of 5.4% for 1.0 × 10−15 M target using the same MWCNTs-Av-bDNAp nanoplatform, and 6.9% for 1.0 × 10−15 M target using 3 different nanoplatforms. The other genosensor was based on a sandwich hybridiz