Study On A Novel Immobilization Method Of Glucose Oxidase

Glucose oxidase?GOD?,which is specific to the substrate of glucose,it can catalyze glucose to H₂O₂ and gluconic acid in the presence of oxygen molecules and has a wide range of use on biological,chemical and animal husbandry.The free GOD has some disadvantages in the practical application process,which limits its application.Therefore,new types of immobilization method has attracted widespread attention.The new immobilization method is based on a method that reduces enzyme loss by mild means.New immobilization methods that can obtain higher enzyme activity include magnetic,plasma and light.Magnetic materials include the following advantages:1 magnetic response 2 non-toxicity 3 biocompatibility and controllability of the manufacturing process that it can be used as an excellent immobilized carrier;plasma treated materials can modify groups on materials,but not change its own nature.In this experiment,magnetic sodium alginate,modified magnetic nanoparticles and plasma-treated polypropylene films were used to immobilize GOD.The research content of this experiment is specifically divided into the following aspects:?1?A magnetic fluid Fe₃O₄ was first prepared and then combined sodium alginate with it to immobilize GOD.Single factor experiments showed that when the conditions were:The sodium alginate concentration was 1.5%,the mass ratio of sodium alginate to Fe₃O₄ was 5:4,the CaCl₂ concentration was 2%,the glutaraldehyde concentration was0.5%,and the crosslinking time was 1.5 h.The temperature and pH of the immobilized GOD have been improved to a certain extent.?2?The prepared magnetic particles were modified by two methods.One was direct modification with APTES,the other was modified Si layer coated material by APTES.The latter is better.The immobilized enzyme was characterized by FT-IR.The results showed that when the conditions were:2.5%APTES,0.6%glutaraldehyde,and the reaction was carried out at 4°C for 12h.After ten times of immobilized GOD,the immobilized enzyme activity was still 59.22%.?3?The immobilized GOD was immobilized on a polypropylene film treated with a novel immobilization technology-plasma technology.The time of the plasma treatment was studied,and the effect was good when the treatment was performed for 300 s.The changes on the surface of the the polypropylene membrane before and after the immobilization of GOD were observed by using environmental scanning electron microscope?SEM?.It was found that the enzyme was successfully immobilized on the surface of the material.The storage stability of immobilized GOD is about 80%after37d.?4?We compared the magnetic properties of the magnetic spherical alginate beads,modified magnetic nanomaterials,and plasma-treated polypropylene films of the immobilized GOD.At the same time we exploreed the areas where it may be applied.Magnetic material immobilized GOD is easy to recycle and can be used to produce products.If the plasma treatment material solves the problem of its stable operation later,it is believed that there are infinite potentials for applications in food and industry.