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

MUJICA, MICHAEL LÓPEZ; TAMBORELLI, ALEJANDRO; CASTELLARO, ANDRÉS; BARCUDI, DANILO; RUBIANES, MARÍA D.; RODRÍGUEZ, MARCELA C.; SAKA, HÉCTOR A.; BOCCO, JOSÉ L. (CO-CORRESPONDING AUTHOR); DALMASSO, PABLO R.; RIVAS, GUSTAVO A.

Biosensors and Bioelectronics: X

Elsevier Ltd

Lugar: Amsterdam; 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