Biocompatible nanostructured magnesium oxide-chitosan platform for genosensing application

A novel organic–inorganic platform comprising of chitosan (CH) modified nanostructured magnesium oxide (nanoMgO) has been electrophoretically deposited on the indium-tin-oxide (ITO) substrate. The single stranded probe DNA (ssDNA) sequence of Vibrio cholerae has been covalently functionalized onto CH-nanoMgO/ITO surface. The cytotoxicity assay of nanoMgO particles, examined using human intestinal cell line (INT 407), reveals no significant cytotoxicity at the given doses in the range of 50–350 μg/mL. The X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and various microscopic techniques have been employed for the structural and morphological analysis of the fabricated electrodes. The electrochemical response studies of ssDNA and fragmented genomic DNA hybridized electrode (dsGDNA/CH-nanoMgO/ITO) have been carried out using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The dsGDNA/CH-nanoMgO/ITO bioelectrode exhibits a linear response in the range 100–500 ng/μL with improved sensitivity of 36.72 nA/ng/cm2, faster response time of 3 s and high stability of 3–4 months under refrigerated condition. The lower detection limit of fabricated genosensor has been estimated as 35.20 ng/μL and it shows good reproducibility/repeatability.

► Chitosan modified nanostructured magnesium oxide biomaterial based genosensor is presented.
► Biocompatibility of nanoMgO confirmed by MTT assay using human intestinal cell line (INT 407).
► High sensitivity, fast response time, low detection limit and high stability found.