| Surface fluorescence enhancement effect is widely used in various fields of the detection of biological macromolecules, materials analysis and environmental monitoring. Therefore, preparing a substrate which has a good surface fluorescence enhancement effect becomes a hot research direction in recent years.We used silver nitrate as oxidant, sodium citrate as reductant, and synthesized spherical silver nanoparticles by oxidation-reduction process. Ag/BSA core-shell structure nanoparticles were fabricated by deposition method and self-assembling onto Ag nanoparticles. The characterizations of silver nanoparticles and Ag/BSA core-shell structure nanoparticles were characterized by scanning electron microscope, transmission electron microscope and X-ray diffraction. We respectively studied the fluorescence enhancement effects of Ag nanoparticles and Ag/BSA nanoparticles for polystyrene, and then took comparative analysis.The results showed that the best reaction time was 5min, and Ag nanoparticles with the average diameter 50-65nm were synthesized. After adding different qualities of bovine serum albumin, Ag/BSA nanoparticles approximately 80.8nm and 100.6nm in effective diameter were fabricated. Ag nanoparticles and Ag/BSA nanoparticles were spherical, and had good monodispersity. Furthermore, BSA was effectively coated on the surface of Ag nanoparticles. The UV absorption spectra results indicated that, the adding of BSA made the density electron on the surface of Ag nanoparticles changed and increased diameters of nanoparticles. Then these two phenomena caused the red shift of the plasma resonance absorption peak. The fluorescence emission spectra results indicated that, Ag nanoparticles can enhanced the fluorescence intensity of PS. What’s more, fluorescence intensity of PS enhanced from 100 to 6000 by Ag/BSA nanoparticles. It indicated that BSA isolation layer had significant enhancement effect on fluorescence intensity of PS near the surface of Ag. |
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