英文摘要 |
In this report, modification of iron oxide nanoparticles with basic amino acids in an aqueous solution with controlled pH at 25℃ and their adsorption property of plasmid were reported. TEM analyses showed that the size of the modified nanoparticles was same as the unmodified nanoparticles. These functionalized nanoparticles had a superparamagnetic property and could be re-dispersed well in aqueous media. In both of modified condition (pH 3.6 and pH 10.5), the values of zeta potential of the modified nanoparticles were more positive than that of unmodified nanoparticles. This phenomenon revealed an effective change of the particle properties after the modification of nanoparticles. In addition, we also confirmed from Zeta potential and TGA analyses that both the modified conditions and various basic amino acids could affect the adsorption type and the adsorption amount of basic amino acids. The TGA data proved that amino acids were adsorbed physically on the particle surface under the modified condition of pH 10.5 and chemisorptions occurred when the modified condition was pH 3.6. However, introducing basic amino acids onto the particle surfaces led to more positive of zeta potential and hence increased the efficiency of plasmid binding. In addition, the behavior of their adsorption of plasmid was in agreement with Langmuir isotherm. Comparing the efficiencies of their adsorption of plasmids, the order was pH3.6/Fe3O4-arginine>pH3.6/Fe3O4-histidine>pH3.6/Fe3O4-lysine>pH10.5/Fe3O4-arginine> pH10.5/Fe3O4-histidine>pH10.5/Fe3O4-lysine>unmodified Fe3O4. |