Electrospinning is a simple and versatile technique for the fabrication of polymeric nanofibrous membranes with high surface to volume ratio. Besides the large surface area of the fibrous membranes, their dimensional stability and flexibility allows the immobilization of biomolecules on to the nanofiber surfaces. Therefore, electrospun nanofibers have been extensively used in enzyme electrodes. This thesis examines the glucose biosensor application of electrospun polyvinyl alcohol (PVA) nanofibers – carbon nanotube (CNT) nanocomposite membranes. By manipulating the structural design and the composition of the nanocomposite membranes, glucose sensing efficiency of the five different enzyme electrodes a) Glucose oxidase (GOx) immobilized PVA electrospun electrode, b) Glucose oxidase (GOx) immobilized PVA electrospun electrode containing multi-walled carbon nanotube (MWCNT), c) Glucose oxidase (GOx) immobilized PVA electrospun electrode containing Poly(diallyldimethylammonium chloride) (PDDA) functionalized multi-walled carbon nanotube (MWCNT) d) Glucose oxidase (GOx) immobilized PVA electrospun electrode containing Poly(diallyldimethylammonium chloride) (PDDA) functionalized single-walled carbon nanotube (SWCNT), e) Interfacially cross-linked PVA electrospun electrode containing Poly(diallyldimethylammonium chloride) (PDDA) functionalized multi-walled carbon nanotube (MWCNT) were comperatively studied. PVA electrospun nanofibers were fabricated by using electrospinning technique. Morphology and average diameter of the fibers were characterized by using Scanning Electron Microscopy (SEM). Average diameter for the neat PVA electrospun fibers were 115 nm. Carbon nanotubes were oxidatively functionalized by acid treatment and addition of functional groups after acid treatment was proved by using Raman Spectroscopy. Glucose sensing activities of the electrodes were amperometrically measured at an applied voltage -0.5 V (vs. Ag/AgCl) in 0.1M phosphate buffer solution (PBS pH 7). Glucose detection sensitivies of the electrodes were calculated as 19.6, 27.7, 67.5, 44.4, 4.0 μA mM-1cm-2 respectively.