Designing and evaluation of a novel electrochemical biosensor based on carbon quantum dots and gold core-shell to detect and measure Human T-lymphotropic Virus-1 (HTLV-1) in clinical samples

Abstract

The objective of this investigation is to introduce an innovative electrochemical biosensor that can swiftly detect HTLV-1 DNA targets without the need for nucleic acid amplification. The biosensor is equipped with a highly precise antisense DNA oligonucleotide. Additionally, we introduce a new core–shell material, CQDs@AuNPs, for the surface modification of glassy carbon electrodes. L-Cysteine is utilized as a conductive bridge to enhance the binding capabilities, electron transfer efficiency, and conductivity. The biosensor incorporates methylene blue (MB) as an electrochemical indicator with differential pulse voltammetry (DPV) technique, facilitating swift detection within a mere 20 min. Furthermore, it has been able to attain a detection limit of 0.7 aM and quantitation limit of 6 copies/µL with an impressive linear range spanning from 10 aM to 100 nM that displays a positive slope along with exhibiting a remarkably high correlation coefficient measuring at approximately 0.99.We tested the biosensor using 40 HTLV-1 DNA real clinical samples, comprising 30 positive and 10 negative samples, as determined by standard RT-PCR. The biosensor demonstrated a specificity of 96.67% and an exceptional sensitivity of 100%. Rigorous quantitative analysis and statistical techniques, including t-tests, cutoff value determination, receiver operating characteristic curves, and box diagrams, clearly differentiated between the positive and negative groups. These findings underscore the potential of our innovative biosensor as a rapid, precise, and cost-effective tool for early detection of HTLV-1, which holds promise for efficient management and control of the virus.