In situ anchor of magnetic Fe304 nanoparticles （NPs） onto the surface of natural maifanite was realized by chemical oxidation coprecipitation in hot alkaline solution. The Fe304/maifanite composites were characteriz...In situ anchor of magnetic Fe304 nanoparticles （NPs） onto the surface of natural maifanite was realized by chemical oxidation coprecipitation in hot alkaline solution. The Fe304/maifanite composites were characterized by XRD, FTIR, SEM, and TEM. These results indicated that polycrystalline Fe304 NPs with inverse spinel structure were formed and tightly dispersed on maifanite surface. Based on the measurement of surface Zeta potential of maifanite at different medium pHs, the possible combination mechanism between natural maifanite and Fe304 NPs was proposed. Then, the as- obtained composites were developed as highly efficient heterogeneous Fenton-like catalyst for the discoloration of an azo dye, Methyl Orange （MO）. The comparative tests on MO discoloration in different systems revealed that Fe304/maifanite composite exhibited much higher Fenton-like catalytic activity than Fe304 NPs and the heterogeneous Fenton- like reaction governed the discoloration of MO. Kinetic results clearly showed that MO discoloration process followed the second-order kinetic model. Fe304/maifanite compo- sites exhibited the typical ferromagnetic property detected by VSM and could be easily separated from solution by an external magnetic field.展开更多
Magnetic Fe304@SiO2 nanoparticles with superparamagnetic properties were prepared via a reverse mi-croemulsion method at room temperature. The as-prepared samples were characterized by transmission electron mi-croscop...Magnetic Fe304@SiO2 nanoparticles with superparamagnetic properties were prepared via a reverse mi-croemulsion method at room temperature. The as-prepared samples were characterized by transmission electron mi-croscopy（TEM）, X-ray diffractometry（XRD）, and vibrating sample magnetometry（VSM）. The Fe304@SiO2 nanopar-ticles were modified by （3-aminopropyl）triethoxysilane（APTES） and subsequently activated by glutaraldehyde（Glu）.Protein A was successfully immobilized covalently onto the Glu activated Fe304@SiO2 nanoparticles. The adsorptioncapacity of the nanoparticles was determined on an ultraviolet spectrophotometer（UV） and approximately up to 203mg/g of protein A could be uniformly immobilized onto the modified Fe304@SiO2 magnetic beads. The core-shell ofthe Fe304@SiO2 magnetic beads decorated with protein A showed a good binding capacity for the chime-ric anti-EGFR monoclonal antibody（anti-EGFR mAb）. The purity of the anti-EGFR mAb was analyzed by virtue ofHPLC. The protein A immobilized affinity beads provided a purity of about 95.4%.展开更多
基金This work was financially supported by the National Natural Science Foundation of China （Grant No. 51404083）, the Program for New Century Excellent Talents in Heilongjiang Provincial Universities （Grant No. 1253-NCET-010）, the Research Development Fund of Nianzishan Institute of Maifanite, Qiqihaer （Grant No. 201406）, and the Natural Science Foundation of Heilongjiang Province, China （Grant No. E2015065）.
文摘In situ anchor of magnetic Fe304 nanoparticles （NPs） onto the surface of natural maifanite was realized by chemical oxidation coprecipitation in hot alkaline solution. The Fe304/maifanite composites were characterized by XRD, FTIR, SEM, and TEM. These results indicated that polycrystalline Fe304 NPs with inverse spinel structure were formed and tightly dispersed on maifanite surface. Based on the measurement of surface Zeta potential of maifanite at different medium pHs, the possible combination mechanism between natural maifanite and Fe304 NPs was proposed. Then, the as- obtained composites were developed as highly efficient heterogeneous Fenton-like catalyst for the discoloration of an azo dye, Methyl Orange （MO）. The comparative tests on MO discoloration in different systems revealed that Fe304/maifanite composite exhibited much higher Fenton-like catalytic activity than Fe304 NPs and the heterogeneous Fenton- like reaction governed the discoloration of MO. Kinetic results clearly showed that MO discoloration process followed the second-order kinetic model. Fe304/maifanite compo- sites exhibited the typical ferromagnetic property detected by VSM and could be easily separated from solution by an external magnetic field.
文摘Magnetic Fe304@SiO2 nanoparticles with superparamagnetic properties were prepared via a reverse mi-croemulsion method at room temperature. The as-prepared samples were characterized by transmission electron mi-croscopy（TEM）, X-ray diffractometry（XRD）, and vibrating sample magnetometry（VSM）. The Fe304@SiO2 nanopar-ticles were modified by （3-aminopropyl）triethoxysilane（APTES） and subsequently activated by glutaraldehyde（Glu）.Protein A was successfully immobilized covalently onto the Glu activated Fe304@SiO2 nanoparticles. The adsorptioncapacity of the nanoparticles was determined on an ultraviolet spectrophotometer（UV） and approximately up to 203mg/g of protein A could be uniformly immobilized onto the modified Fe304@SiO2 magnetic beads. The core-shell ofthe Fe304@SiO2 magnetic beads decorated with protein A showed a good binding capacity for the chime-ric anti-EGFR monoclonal antibody（anti-EGFR mAb）. The purity of the anti-EGFR mAb was analyzed by virtue ofHPLC. The protein A immobilized affinity beads provided a purity of about 95.4%.
