Immobilization of glucose oxidase and urease in hydrogel matrices

Gurel, I
Arica, MY
Hasırcı, Vasıf Nejat
Immobilization of glucose oxidase and urease in hydrogels of 2-hydroxyethyl methacrylae, and N-vinyl pyrrolidone (NVP) was achieved by irradiation (using UV kand gamma-rays). The effect of radiation on entrapment efficiencies, retention of activities and swelling rates was obtained. To optimize the system, duration of exposure, reaction temperature, co-monomer concentrations, initiator and cross linker compositions were varied. The repeated reusability of the generated products was also tested. It was found that gamma-irradiation at very low temperatures did not have a detrimental effect on the enzyme activity. Incorporation of more hydrophilic monomer (NVP), influenced matrix morphology and entrapment efficiencies and retained enzyme activities positively Repeated use studies revealed that there is a gradual loss (higher in the NVPL incorporated group) of activity following 10 runs. With the use of the present approach it is believed that the construction of biosensors using hydrogels of arious forms is possible.


Sulfated Zirconia Modified SBA-15 Catalysts for Cellobiose Hydrolysis
Yılmaz, Ayşen; Üner, Deniz; Yılmaz, Ayşen; van Santen, Rutger A.; Hensen, Emiel J. M. (2011-01-01)
Zirconia modified SBA-15 becomes a very active catalyst for the selective hydrolysis of cellobiose to glucose after sulfation. Spectroscopic investigations indicate the presence of Bronsted acid sites with similar properties to those present in conventional sulfated zirconia. Indications are found that the sulfate groups attached to zirconia interact with silanol groups of SBA-15. The catalytic activity in cellobiose hydrolysis correlates well with results for temperature-programmed decomposition of i-propy...
In situ-generated PVP-stabilized palladium(0) nanocluster catalyst in hydrogen generation from the methanolysis of ammonia-borane
Erdogan, Huriye; Metin, Oender; Özkar, Saim (2009-01-01)
Herein, we report the in situ generation of poly(N-vinyl-2-pyrrolidone) (PVP)-stabilized palladium(0) nanoclusters and their catalytic activity in hydrogen generation from the methanolysis of ammonia-borane (AB). The PVP-stabilized palladium(0) nanoclusters with an average particle size of 3.2 +/- 0.5 nm were formed from the reduction of palladium(II) acetylacetonate during the methanolysis of AB in the presence of PVP at room temperature. The palladium(0) nanoclusters are highly stable in solution for exte...
Immobilization of invertase and glucose oxidase in poly 2-methylbutyl-2-(3-thienyl) acetate/polypyrrole matrices
Isik, S; Alkan, S; Toppare, Levent Kamil; Cianga, I; Yagci, Y (Elsevier BV, 2003-12-01)
Immobilization of invertase and glucose oxidase in conducting polypyrrole and copolymers of poly 2-methylbutyl-2-(3-thienyl) acetate with pyrrole were achieved via electrochemical method. Sodium dodecyl sulphate was found to be the most suitable supporting electrolyte. Maximum reaction rate, Michaelis-Menten constant and optimum temperatures were determined for native and immobilized enzymes. Storage and operational stabilities of enzyme electrodes were also investigated.
Immobilization of glucose oxidase in conducting graft copolymers and determination of glucose amount in orange juices with enzyme electrodes
Yildiz, HB; Kiralp, S; Toppare, Levent Kamil; Yagci, Y (Elsevier BV, 2005-12-15)
Glucose oxidase was immobilized in conducting copolymers of three different types of poly(methyl methacrylate-co-thienyl methacrylate). Immobilization of enzyme was carried out by the entrapment in conducting polymers during electrochemical polymerization of pyrrole on the copolymer electrodes. Maximum reaction rate, Michaelis-Menten constants, temperature, pH and operational stabilities were determined for immobilized enzyme. The amount of glucose in orange juices of Turkey was investigated by using enzyme...
DEMIRCIOGLU, H; BEYENAL, H; TANYOLAC, A; Hasırcı, Nesrin (1994-12-01)
Enzyme urease was immobilized in copolymer matrices of 2-hydroxyethyl methacrylate (HEMA) and N-vinyl pyrrolidone (VP). The activities of immobilized urease stored in phosphate buffer solution of pH 7.0 at 4-degrees-C were examined periodically for up to 90 days. For the matrices of higher VP/HEMA mole ratio in the structure, a higher volume increase and enhanced apparent activity were observed, while HEMA polymer alone proved to have the most stable matrix for prolonged activity. No appreciable amount o...
Citation Formats
I. Gurel, M. Arica, and V. N. Hasırcı, “Immobilization of glucose oxidase and urease in hydrogel matrices,” TURKISH JOURNAL OF CHEMISTRY, pp. 387–393, 1997, Accessed: 00, 2020. [Online]. Available: