title: Fabrication of a tunable glucose biosensor based on zinc oxide/chitosan-graft-poly(vinyl alcohol) core-shell nanocomposite.
abstract: A potentiometrically tuned-glucose biosensor was fabricated using core-shell nanocomposite based on zinc oxide encapsulated chitosan-graft-poly(vinyl alcohol) (ZnO/CHIT-g-PVAL). In a typical experiment, ZnO/CHIT-g-PVAL core-shell nanocomposite containing <20 nm ZnO nanoparticles was synthesized using wet-chemical method. The glucose responsive bio-electrode, i.e., glucose oxidase/ZnO/chitosan-graft-poly(vinyl alcohol) (GOD/ZnO/CHIT-g-PVAL/ITO) was obtained by immobilization of glucose oxidase (GOD) onto the electrode made of resulting ZnO core-shell nanocomposite coated on the indium-tin oxide (ITO) glass substrate. The ZnO/CHIT-g-PVAL/ITO and GOD/ZnO/CHIT-g-PVAL electrodes were characterized with Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), whereas ZnO/CHIT-g-PVAL size of core-shell nanoparticles were measured using transmission electron microscopy (TEM). The electrostatic interaction between GOD and ZnO/CHIT-g-PVAL provided the resulting tuned enzyme electrode with a high degree of enzyme immobilization and excellent lifetime stability. The response studies were carried out as a function of glucose concentration with potentiometric measurement. The GOD/ZnO/CHIT-g-PVAL/ITO bioelectrode has showed a linear potential response to the glucose concentration ranging from 2 μM to 1.2mM. The glucose biosensor exhibited a fast surface-controlled redox biochemistry with a detection limit of 0.2 μM, a sensitivity of >0.04 V/μM and a response time of three sec. ZnO/CHIT-g-PVAL core-shell nanocomposite could be a promising nanomaterials for a range of enzymic biosensors.
authors.affiliation: Department of Polymer Science, Bhaskaracharya College of Applied Sciences, University of Delhi, New Delhi 110 075, India.
authors.forename: S K
authors.initials: SK
authors.lastname: Shukla
authors.forename: Swapneel R
authors.initials: SR
authors.lastname: Deshpande
authors.forename: Sudheesh K
authors.initials: SK
authors.lastname: Shukla
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Tiwari
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology; D055162:Biocatalysis; D015374:Biosensing Techniques / Q000379:methods*; D048271:Chitosan / Q000737:chemistry*; D004566:Electrodes; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D005949:Glucose Oxidase / Q000737:chemistry / Q000378:metabolism; D053761:Nanocomposites / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D011199:Potentiometry; D013997:Time Factors; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D011142:Polyvinyl Alcohol; D048271:Chitosan; D005949:Glucose Oxidase; D005947:Glucose; D015034:Zinc Oxide