Immobilized GOD By Using CuTAPP-Fe₃O₄ Nanoparticle Composite And Its Application

Fiber optic biosensor is a new research branch of biosensor.Compare with others,it has many advantages such as high detection and immunity from electromagnetism field.The research in fiber optic biosensor has get great progress in this ten years,and it has been widely used in medical science,biological engineering, food industries and environment monitoring.Biosensitive material is an important part of fiber optic biosensor.The characters of the materials influence the whole fiber optic biosensor greatly.Organic-inorganic nanaparticle composite is a novel interdiscipline,it has good application in the future. Organic-inorganic nanaparticle composite has both the advantage of organic substance and inorganic nanocomposite.It has a wide application in immobilization of biological substances.Fiber optic glucose biosensor especially widly applied in detecting diabetes.In this thesis,a new kind of carrier tetra(p-aminophenyl)porphyrin copper (CuTAPP)-Fe₃O₄ with excellent characters was successfully prepared and was used in GOD immobilization.The immobilized GOD has good excellent performance.The fiber optic glucose sensor was designed and constructed,and several tests were performed to detect the concentration of glucose in solution.The work of this thesis includes mainly three aspects as followed:(1)The CuTAPP-Fe₃O₄ nanoparticle composite was prepared by in situ complex technology.The composite were characterized by IR,TEM,XRD and EDS.The nanoparticle composites took the shape of roundish spheres with their mean diameter of about 50 nm.The nanoparticle composites have good dispersion,excellent compatibility and abundant active functions on the surface for immobilization of GOD.(2)The GOD was immobilized on the surface of the CuTAPP-Fe₃O₄ nanoparticle composite by crosslinking method.The effects of glutaraldehyde concentration, BSA concentration,the pH on the reaction process and the amount of enzyme on the activity of immobilized enzyme were studied.After immobilization,the best pH,temperature of immobilized GOD catalyse glucose were studied.The immobilized GOD has better stabilities in heat,storage and operation.(3)A fiber optic glucose biosensor based on fluorescence quenching was designed and fabricated.The performance of this sensor in detecting glucose was investigated.