Highly sensitive protein functionalized nanostructured hafnium oxide based biosensing platform for non-invasive oral cancer detection

We report results of the studies relating to the development of a non-invasive, label free immunosensor based on nanostructured hafnium oxide (hafinia) deposited onto indium tin oxide (ITO) coated glass for oral cancer biomarker (CYFRA-21-1) detection in human saliva. The nanostructured hafnia (nHfO(2)) has been synthesized via one step low temperature hydrothermal process and modified with 3-aminopropyltriethoxy silane (APTES) for covalent immobilization of monoclonal antibodies (anti-CYFRA-21-1). Bovine serum albumin (BSA) was used to block non-specific sites at the anti-CYFRA-21-1/APTES/nHfO(2)/ITO electrode surface. The structural, morphological and spectroscopic characterization of the synthesized nanomaterials and fabricated electrodes has been carried out using Xray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) studies, respectively. The results of response studies conducted on BSA/anti-CYFRA-21-1/APTES/nHfO(2)/ITO immunoelectrode reveal that this biosensor has high sensitivity (9.28 mu AmLng(-1) cm(-2)), wide linear detection range (2-18 ng mL(-1)) and fast response time (15 min). This immunosensor has been validated with enzyme linked immunosorbent assay (ELISA) in saliva samples of oral cancer patients. (C) 2016 Elsevier B.V. All rights reserved.