Cubic CeO2 planted reduced graphene oxide based highly sensitive biosensor for non-invasive oral cancer biomarker
Abstract
Herein, results of cerium oxide nano cubes (ncCeO2)-reduced graphene oxide (RGO) based nanocomposite were reported for detection of oral cancer biomarker, cytokeratin fragment-21-1(Cyfra-21-1) using the electrochemical technique. A nanocomposite of ncCeO2-RGO was prepared by in-situ reduction of graphene oxide (GO) in the presence of ncCeO2 using hydrazine hydrate. A Raman spectrum has confirmed the presence of ncCeO2 in the matrix of RGO.The chemical composition of ncCeO2-RGO nanocomposite was determined by X-ray photoelectron spectroscopy (XPS). X-ray diffraction (XRD) study has depicted the presence of crystalline ncCeO2 and amorphous nature of RGO. Thin film deposition of ncCeO2-RGO composites was spin coated on the indium tin oxide (ITO) coated glass surface and used for co-immobilization of specific antibody Cyfra-21-1 by N-ethyl-N-(3-dimethyl aminopropyl) carbodiimide hydrochloride, N-hydroxysuccinimide (EDC-NHS) chemistry. Electrochemical response studies were monitored by using differential pulse voltammetry technique at the range 0.625 pg mL-1 – 15 ng mL-1 and found the best linear response from 0.625 pg mL-1 to 0.01 ng mL-1 with lower detection limit of 0.625 pg mL-1 and sensitivity of 14.5 µA ng-1 mL cm-2 with R2 0.98 with improved results as compared to the previously reported work. This BSA/Anti-Cyfra-21-1/ncCeO2-RGO/ITO immunosensor shows selectivity towards Cyfra-21-1 in presence of glucose, sodium chloride, mucin 16, interleukin 8.
