Electrochemical DNA-nano biosensor for the detection of cervical cancer-causing HPV-16 using ultrasmall Fe3O4-Au core-shell nanoparticles

This paper reports a label-free biosensor for detecting human papillomavirus type 16 (HPV-16). For this purpose, the surface of the screen-printed carbon electrodes (SPCEs) was coated with Fe3O4-Au core-shell nanoparticles (NPs) using a green and facile eco-friendly method. The modified surfaces of the electrodes were then functionalized with thiolated single-strand DNA (ssDNA) probe human papillomavirus (HPV) DNA sequences. Next, the hybridization events with the immobilized probe DNA were monitored by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) using [Fe(CN)6]3-/4- as the redox indicator. Our results demonstrate that the modified electrodes could distinguish the redox current signals of [Fe(CN)6] 3-/4- due to the absence/ presence of the immobilized probe DNA. Furthermore, quantitative estimations of the concentration of the probe DNA were also possible. Optimal performance was obtained for probe DNA concentrations between 1 and 10 & mu;M. The best performance of our HPV biosensor was obtained for probe DNA concentration of 5 & mu;M, for which the limit of detection and sensitivity of our developed sensor resulted to be 0.1 nM and 2.4 & mu;A/nM, respectively.

Automated summary

This paper presents a label-free biosensor for detecting HPV-16 using screen-printed carbon electrodes coated with Fe3O4-Au core-shell nanoparticles. Thiolated ssDNA probe HPV DNA sequences were immobilized on the modified electrode surfaces and hybridization events were monitored using cyclic voltammetry and differential pulse voltammetry. The biosensor showed good performance with a limit of detection of 0.1 nM and a sensitivity of 2.4 μA/nM at a probe DNA concentration of 5 μM.