Rapid and Label-Free Electrochemical DNA Biosensor Based on a Facile One-Step Electrochemical Synthesis of rGO-PPy-(L-Cys)-AuNPs Nanocomposite for the HTLV-1 Oligonucleotide Detection

Biotechnol Appl Biochem. 2020 Jun 15. doi: 10.1002/bab.1973. Online ahead of print.

Abstract

Human T cell leukemia virus type 1 (HTLV-1) as the first human retrovirus is currently a serious endemic health challenge. Despite the use of assorted molecular or serological assays for HTLV-1 detection, there are several limitations due to the lack of a confirmatory test that may affect the accuracy of the results. Herein, a novel label-free biosensor for the detection of HTLV-1 Tax gene has been reported. An electrochemical facile ecofriendly synthesis method has been demonstrated based on a synthesis of nanocomposite of reduced graphene oxide, polypyrrole, and gold nanoparticles (rGO-PPy-(l-Cys)-AuNPs) deposited on the surface of screen-printed carbon electrode. Electrochemical techniques were used to characterize and study the electrochemical behavior of the rGO-PPy-(l-Cys)-AuNPs, which exhibited a stable reference peak at 0.21 V associated with hybridization forms by applying the differential pulse voltammetry. The designed DNA biosensor presented a wide linear range from 0.1 fM to 100 µM and a low detection limit of 20 atto-molar. The proposed biosensor presented in this study provides outstanding selectivity, sensitivity, repeatability, and reproducibility.

Keywords: HTLV-1; Human T cell leukemia virus type 1; electrochemical DNA biosensor; electrochemical biosensor; label-free.