The highly sensitive impedimetric biosensor in label free approach for hepatitis B virus DNA detection based on tellurium doped ZnO nanowires

The highly sensitive impedimetric biosensor in label free approach for hepatitis B virus DNA (HPV DNA) detection based on tellurium doped ZnO nanowires was fabricated. The NWs were grown by hybrid thin film oxidation in the physical vapor deposition (PVD) mechanism. The morphology characterization of the synthesized NWs was performed by field emission scanning electron microscopy (FESEM) and the images demonstrated that the diameter and the length of the materialized NWs were around 50nm and several micrometers, respectively. The high-resolution transmission electron microscopy (HRTEM) image indicated that the fabricated NWs were crystalline and their phase characterization was validated by the X-ray diffraction pattern (XRD pattern). The single-stranded DNA (ss DNA) probe was immobilized on the surface of the Te-ZnO NWs. The electrochemical impedance spectra (EIS) measurements showed high response sensitivity after hybridization with complementary oligonucleotides. The biosensor could distinguish complementary target from non-complementary and mismatch oligonucleotides. The HBV biosensor could respond to complementary target in the concentrations range from 1pM to 1 mu M. The limit of detection (LOD) of the biosensor was 0.1pM. The stability of the HBV DNA biosensor was investigated and biosensor could show 95% of its initial responses after 8weeks maintenance.