Preparation And Application Of New Organic-inorganic Nanomaterials For Immobilized Enzyme

Natural enzymes,with immense catalytic capability,high substrate specificity and low toxicity,have attracted a lot of research interests for its application in medical,biosenor and food industry fields.However,the disadvantages of enzymes such as the high costs and the low stability caused by high temperature and extreme pH limited its production and practical application.The development of immobilization methods can be useful in meeting excellent stability and reusability.The activity of enzymes usually turned down after being immobilizing,mainly due to mass transfer and contact reaction.Owing to the large specific surface area and the high affinity with substrates,nanomaterials have attracted the great attention.In this study,three facile approaches for the synthesis of organic-inorganic hybrid nanomaterials were reported.(1)A facile approach for the synthesis of enzyme-inorganic hybrid nanoflowers and their application was described.The hybrid nanoflowers were synthesized in aqueous solution using calcium hydrogen phosphate(CaHPO4)as the inorganic component and alcalase as the organic component.The results showed that the hydrolysis properties of immobilized alcalase were increased by compared with that of free alcalase.The as-prepared hybrid nanoflowers exhibited good reusability,high thermo stability,pH stability and long storage life.The immobilized alcalase maintained more than 85.4%of the enzyme activity after seven times.Furthermore,the soybean protein hydrolysates(SPHs)hydrolyzed by immobilized alcalase showed higher radical-scavenging capacity,calcium-binding capacity and solubility than free alcalase.(2)In order to decrease the cost of enzyme,we developed a facile method for preparing magnetic multi-enzyme co-embedded nanomaterials,using glucose oxidase(GOx)and horseradish peroxidase(HRP)as the model enzyme,and Cu3(PO4)2 as the inorganic component.Compared with free enzymes,immobilized enzymes displayed excellent magnetic response,enzyme activity,stability and reusability.The immobilized enzymes showed more than 80%activity after ten cycles.Moreover,this novel biosensor greatly enhances the sensitivity and sensitivity of glucose detection.(3)A facile co-immobilization of Glucose oxidase(GOx)and Horseradish peroxidase(HRP)in the matrix Co-immobilization of Copper ions and GMP was developed.Immobilized enzymes revealed high catalytic efficiency,selectivity,and enhanced stability because of rigid framework.The reusability of immobilized enzymes revealed excellent performance with more than 81%relative activity retained after used eight times.The co-immobilized enzymes demonstrated an excellent selectivity and sensitivity in the development of glucose biosensor.