Summary:The cheapness, easy availability of raw materials, easy synthesis, good environmental stability, good electrical and optical properties, simple doping and de-doping chemistry makes the place of polymers very important in sensing applications. Besides all the conducting polymers, polyaniline (PANI) has found comfortable and suitable for the immobilization of biomolecules. In the present study, we have fabricated PANI-ZnO nanocomposite by chemical polymerization route and used to modify cladding of an optical fiber for immobilization of enzyme glucose oxidase (GOx) on it with the help of cross-linking technique for the development of cladding modified fiber optic intrinsic glucose biosensor (FOIGB). The properties of deposited PANI-ZnO nanocomposite have been studied. The sensitivity of prepared sensor in the form of power and modal power distribution (MPD) has also been reported.

Summary: Polyaniline (PANI) and its composites have drawn considerable interest because of their economical importance, good environmental stability and satisfactory conductivity among the conductive polymers. Polymers are playing an increasingly important role in the development of biosensors. The use of conducting polymer composites for the construction of biosensor is increasing nowadays for the immobilization of biomolecules as it enhances the activity and performance of the sensor. In the present investigation, we have used PANI-oxalic acid (OA) for the cladding modification to prepare fiber optic intrinsic glucose biosensor (FOIGB) for detection of glucose. PANI-OA composite have shown good binding toward enzyme-glucose oxidase (GOx) and high biological activity that results in enhanced sensing characteristics. This investigation highlights approach to synthesize PANI-OA composite and its applications in cladding modified FOIB technology. The characterizations were made using X-ray diffraction and scanning electron microscopy (SEM) techniques. The results revealed the formation of homogeneous, PANI-OA film on sensing element. The sensing response of FOIGB toward glucose was measured by monitoring variation in power with varying glucose concentration.