title: Activity of glucose oxidase immobilized onto Fe3+ attached hydroxypropyl methylcellulose films.
abstract: Hydroxypropyl methylcellulose (HMPC) insoluble films were prepared by (60)Co-γ irradiation of 10% (w/w) aqueous solutions of hydroxypropyl methylcellulose. The adsorption of Fe(3+) onto HPMC films was studied in the range of pH 3.0-7.0. The effect of initial concentrations of Fe(3+) solutions on adsorption capacity was studied in the range of 100-1000 ppm. Maximum adsorption capacity was found as 250 mg Fe(3+)/g dry HPMC film at pH 5.0. The structure and the morphology of Fe(3+)-attached HPMC film were evaluated by using FTIR/ATR and SEM-EDX methods. Glucose oxidase (GOX) immobilization on both pristine HPMC and maximum Fe(3+)-attached HPMC film was investigated in aqueous solutions containing different amount of GOX and at different pHs. Maximum GOX adsorption capacity was found as 500 mg/g Fe(3+)-attached HPMC film. Residual activity of GOX on pristine HPMC and Fe(3+)-attached HPMC films was investigated with changing pH. While maximum residual GOX activity was observed at pH 6.0 for free enzyme, it was obtained by HPMC and Fe(3+)-attached HPMC at pH 7.0. GOX desorption studies were achieved by using pH 6.0 buffer (I=0.02 M) and 0.1 M EDTA solutions. The long-term stability and activity studies of GOX, which is immobilized onto Fe(3+)-attached HPMC films are still under our investigation.
authors.affiliation: University of Hacettepe, Faculty of Science, Department of Chemistry, Beytepe, Ankara, Turkey.
authors.forename: Sevgi
authors.initials: S
authors.lastname: Sözügeçer
authors.forename: Nursel Pekel
authors.initials: NP
authors.lastname: Bayramgil
mesh_terms: D003432:Cross-Linking Reagents; D004492:Edetic Acid; D004800:Enzymes, Immobilized / Q000737:chemistry*; D005949:Glucose Oxidase / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D065347:Hypromellose Derivatives; D007202:Indicators and Reagents; D007501:Iron / Q000737:chemistry*; D008567:Membranes, Artificial; D008747:Methylcellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D013816:Thermodynamics
chemical_list: D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D007202:Indicators and Reagents; D008567:Membranes, Artificial; D065347:Hypromellose Derivatives; D008747:Methylcellulose; D004492:Edetic Acid; D007501:Iron; D005949:Glucose Oxidase