University of Hacettepe, Faculty of Science, Department of Chemistry, Beytepe, Ankara, Turkey.
Colloids Surf B Biointerfaces. 2013 Jan 1;101:19-25. doi: 10.1016/j.colsurfb.2012.05.029. Epub 2012 Jun 12.
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.
羟丙基甲基纤维素（HMPC）不溶性薄膜是通过 10%（w/w）羟丙基甲基纤维素水溶液的（60）Co-γ辐照制备的。研究了 pH 3.0-7.0 范围内 HPMC 薄膜对 Fe(3+)的吸附。研究了初始 Fe(3+)溶液浓度在 100-1000 ppm 范围内对吸附容量的影响。在 pH 5.0 时，最大吸附容量为 250mg Fe(3+)/g 干 HPMC 薄膜。通过 FTIR/ATR 和 SEM-EDX 方法评估了 Fe(3+)附着的 HPMC 薄膜的结构和形态。在含有不同量 GOX 和不同 pH 的水溶液中，研究了葡萄糖氧化酶（GOX）在原始 HPMC 和最大 Fe(3+)附着的 HPMC 薄膜上的固定化。最大 GOX 吸附容量为 500mg/g Fe(3+)-附着 HPMC 薄膜。研究了 pH 值变化时原始 HPMC 和 Fe(3+)-附着 HPMC 薄膜上 GOX 的剩余活性。游离酶的最大残余 GOX 活性在 pH 6.0 时观察到，而 HPMC 和 Fe(3+)-附着 HPMC 则在 pH 7.0 时获得。通过使用 pH 6.0 缓冲液（I=0.02 M）和 0.1 M EDTA 溶液进行了 GOX 的解吸研究。GOX 固定在 Fe(3+)-附着的 HPMC 薄膜上的长期稳定性和活性研究仍在我们的研究中。
