NANOSTRUCTURED HAFNIUM OXIDE BASED NONINVASIVE BIOSENSOR FOR ORAL CANCER DETECTION

Abstract

This dissertation contains results of the studies relating to fabrication of the non-invasive and label free, novel nanostructured immunosensor platform (BSA/anti-CYFRA-21- 1/APTES/HfO2/ITO) for efficient detection of an oral cancer biomarker (CYFRA-21-1) in saliva. Nanostructured hafnium oxide has been synthesized via one step low temperature hydrothermal process and surface modified with 3-aminopropyltriethoxy silane (APTES) for covalent immobilization of monoclonal anti-CYFRA-21-1. Structural, morphological and spectroscopic characterization of the fabricated electrodes have been carried out using X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and fourier transform infrared spectroscopy (FT-IR). The results of the response studies reveal that the BSA/anti-CYFRA-21-1/APTES/HfO2/ITO immunoelectrode can be used to estimate the CYFRA-21-1 with a high sensitivity of 9.28 μA mL ng-1 cm-2, has a wide linear detection range (LDR) of 2-18 ng mL-1, limit of detection (LOD) as 0.209 ng mL-1 and shelf life of 8 weeks. Further, the sensing results obtained using this immunosensor have been validated with enzyme linked immunosorbent assay (ELISA) in saliva samples of oral cancer patients. The improved biosensing characteristics of the fabricated hafnium oxide based immunoelectrode reveal that this platform can be efficiently utilized for the fabrication of noninvasive point of care device for oral cancer monitoring.