The Study On Adsorption And Immobilization Of Amino Acids, Glutathione And Trypsin On Magnetite Nanoparticles

With the nanotechnology infiltrating into biotechnology ,solving biotechnology problems and promoting it by nanotechnology are being one of the foreland researches . Magnetic inorganic nanoparticle magnetite has the physical and chemical properties of inorganic nanoparticles and magnetism .The composite particles of biology molecular binding to magnetite have broad application foreground in medical treatment, biology chemistry and industry application ,such as magnetic resonance imaging (MRI), biology substance magnetic separation for purification, immunoassay and drug delivery and targeting. But there are many basic research problems in the process of biology molecular binding to magnetite and it need to be thorough studied. So we investigated amino acids, peptide and enzyme adsorbing and binding to magnetite nanoparticles. The paper comprises three researches below:1, Adsorption of amino acids on magnetic magnetite nanoparticles.The magnetite nanoparticles were prepared by co-deposition and characterized by VSM, TEM, BET, Mossbauer spectroscopy. The adsorption of phenylalanine, tyrosine and cysteine on magnetite was studied, and adsorption isotherms of these amino acids on Fe₃O₄ nanoparticles at different pH were determined and their amounts adsorbed were compared individually. Results showed that Freundlich equation is well fitted for the adsorption of the three amino acids on Fe₃O₄ nanoparticles.The adsorption and desorption of phenylalanine, tyrosine adsorbed on Fe₃O₄ nanoparticles are reversible ,it can be erased through adding KNO₃. But irreversible adsorption of cysteine was observed since it cannot be erased in KNO₃ and HC1 solutions. It was suggested that Chemical interactions bonds play an important role in the adsorption .2, Adsorption of glutathione reduced and oxidized on magnetite nanoparticles.The adsorption of glutathione reduced and oxidized on magnetite was studied. and adsorption isotherms of glutathione reduced and oxidized on Fe₃O₄ nanoparticles at different temperature were determined and their amounts adsorbed were compared individually. Results showed that Freundlich equation is well fitted for the adsorption of glutathione reduced and oxidized on Fe₃O₄ nanoparticles.The effect of carbodiimdeportion and pH on glutalhione adsorption also study. The adsorption thermodynamics parameters were obtained,and the adsorption mechanism were studied from adsorption and desorption experiments result. Irreversible adsorption of glutathione reduced and oxidized was observed since it cannot be erased in KNO₃ and HC1 solutions. It was suggested that Chemical interactions bonds play an important role in the adsorption .3, The immobilization of trypsin on magnetite nanoparticles and activity study.The optimization condition of the trypsin immobilization on magnetite nanoparticles was studied. The effects of temperature and pH on the activity and stability of free and immobilization trypsin were investigated including working and storing stability and magnetism,the experiment results showed that the immobilization trypsin had better performance than free trypsin,the preponderance of enzyme immobilization was displayed.