Fe3O4/Au composite particles with core/shell structure were prepared by reduction of Au3+ with hydroxylamine in the presence of an excess of Fe3O4 as seeds.The resultant col-loids,with an average diameter of less than...Fe3O4/Au composite particles with core/shell structure were prepared by reduction of Au3+ with hydroxylamine in the presence of an excess of Fe3O4 as seeds.The resultant col-loids,with an average diameter of less than 100 nm,were obtained;the remaining non-reacted Fe3O4 seeds can be removed by treatment with diluted HCl solution.The Fe3O4/Au colloids ex-hibit a characteristic peak of UV-visible spectra,which largely depend on the size of the particle and the suspension medium.The localized surface plasmon resonance peaks red shift and broaden with increased nanoparticle diameter or increased solvent ionic strength.The optical property is very important in the establishment of means for the detection of biomolecules.展开更多
Using Fe3O4 nano-particles as seeds, a new type of Fe3O4/Au composite particles with core/shell structure and diameter of about 170 nm was prepared by reduction of Au3+ with hydroxylamine in an aqueous solution. Parti...Using Fe3O4 nano-particles as seeds, a new type of Fe3O4/Au composite particles with core/shell structure and diameter of about 170 nm was prepared by reduction of Au3+ with hydroxylamine in an aqueous solution. Particle size analyzer and transmission electron micro-scope were used to analyze the size distribution and microstructure of the particles in different conditions. The result showed that the magnetically responsive property and suspension stability of Fe3O4 seeds as well as reduction conditions of Au3+ to Au0 are the main factors which are crucial for obtaining a colloid of the Fe3O4/Au composite particles with uniform particle dispersion, excellent stability, homogeneity in particle sizes, and effective response to an external magnet in aqueous suspension solutions. UV-Vis analysis revealed that there is a characteristic peak of Fe3O4/Au fluid. For particles with d(0.5)=168 nm, the lmax is 625 nm.展开更多
基金the National Natural Science Foundation of China(Grant No.20273050) the Nat ional High Technology Research and Development Program of China(Grant Nos.2002AA2Z2031&2003AA2Z2080).
文摘Fe3O4/Au composite particles with core/shell structure were prepared by reduction of Au3+ with hydroxylamine in the presence of an excess of Fe3O4 as seeds.The resultant col-loids,with an average diameter of less than 100 nm,were obtained;the remaining non-reacted Fe3O4 seeds can be removed by treatment with diluted HCl solution.The Fe3O4/Au colloids ex-hibit a characteristic peak of UV-visible spectra,which largely depend on the size of the particle and the suspension medium.The localized surface plasmon resonance peaks red shift and broaden with increased nanoparticle diameter or increased solvent ionic strength.The optical property is very important in the establishment of means for the detection of biomolecules.
基金This work was supported by the National Natural Science Foundation of China(Grant No.20273035)the National High Technology Research and Development Program of China(863 Program)(Grant Nos.2002AA2Z2031 and 2001AA224032)the Science and Technology Program of Xi'an(Grant No.GG200148).
文摘Using Fe3O4 nano-particles as seeds, a new type of Fe3O4/Au composite particles with core/shell structure and diameter of about 170 nm was prepared by reduction of Au3+ with hydroxylamine in an aqueous solution. Particle size analyzer and transmission electron micro-scope were used to analyze the size distribution and microstructure of the particles in different conditions. The result showed that the magnetically responsive property and suspension stability of Fe3O4 seeds as well as reduction conditions of Au3+ to Au0 are the main factors which are crucial for obtaining a colloid of the Fe3O4/Au composite particles with uniform particle dispersion, excellent stability, homogeneity in particle sizes, and effective response to an external magnet in aqueous suspension solutions. UV-Vis analysis revealed that there is a characteristic peak of Fe3O4/Au fluid. For particles with d(0.5)=168 nm, the lmax is 625 nm.
