الفهرس 
Introduction and aim of the workOnly 14 pages are availabe for public view
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Abstract
Eight different fungal strains {Trichoderma harzianum S-130, Hypocrea argentinensis S-220, Trichoderma reesei S-131, Penicillium notatum F-158, Trichoderma Pesudokoningii S-128, Trichoderma virdi S-129, Aspragellus niger F-258 and Trichoderma virens S-127} were isolated from soil and orange fruit samples for inexpensive glucose oxidase (GOx) enzyme production. Screening studies for GOx production reveals that the Penicillium notatum F- 158 (P. notatum) produced the highest extra-cellular GOx activity. Culture conditions of P. notatum for production of GOx enzyme {fermentation media, pH, C and N sources, incubation temperature and period of incubation} were optimized. The produced GOx was purified using ammonium sulfate fractionation, dialysis and gel filtration chromatography. The purified enzyme was immobilized on MWCNT, graphen, chitosan and TiO2. The most suitable matrix immobilization was MWCNT. The physical and chemical character of the free and immobilized GOx was examined. The optimum pH value of the medium and the suitable temperature for the free and immobilized enzyme᾿ action were 7 and 35 Co, respectively. Km of 0.24 and 2 mM were achieved for the free and immobilized enzyme, respectively. An effective novel biosensor was then developed for glucose determination. It based on immobilization of this extracted P. notatum GOx enzyme, MWCNTs, aritificial ferrocene (Fc) redox mediator and nafion polymer (NF) on glassy carbon electrode (GCE) surface. Fc acts as an electron relay between enzyme and MWCNTs/GCE. The synergy of MWCNTs and Fc improves the electrocatalytic effect of Fc to the oxidation of glucose utilizing the immobilized enzyme. Low potential of Fc applied in amperometric measurements avoids interfere of the main electroactive species present in the human serum samples. This biosensor showed broad linear ranges {2.80×10-4 to 14.99×10-3 M (5 - 270 mg dL–1)} and low limit of detection of 8.68×10-6 M (0.16 mg dL-1) for glucose determination. The achieved glucose concentrations in different serum samples using both the extracted and the commercial GOx enzyme biosensors are consistent with normal values in human blood and with colorimetric method indicating that such biosensor could be used clinically.