Magnesium oxide grafted carbon nanotubes based impedimetric genosensor for biomedical application

Abstract

Nanostructured magnesium oxide (size<10nm) grafted carboxyl (COOH) functionalized multi-walled carbon nanotubes (nMgO–cMWCNTs) deposited electrophoretically onto indium tin oxide (ITO) coated glass electrode and have been utilized for Vibrio cholerae detection. Aminated 23 bases single stranded DNA (NH2–ssDNA) probe sequence (O1 gene) of V. cholerae has been covalently functionalized onto nMgO–cMWCNTs/ITO electrode surface using EDC-NHS chemistry. This DNA functionalized MgO grafted cMWCNTs electrode has been characterized using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical techniques. The results of XPS studies reveal that sufficient O–CåO groups present at the nMgO–cMWCNTs surface are utilized for DNA binding. The results of hybridization studies conducted with fragmented target DNA (ftDNA) of V. cholerae using electrochemical impedance spectroscopy (EIS) reveal sensitivity as 3.87Ωng−1cm−2, detection limit of ∼21.70ngµL−1 in the linear range of 100–500ngµL−1 and stability of about 120 days. The proposed DNA functionalized nMgO–cMWCNTs nanomatrix provides a novel impedimetric platform for the fabrication of a compact genosensor device for biomedical application.