Silver based nanomaterials - fluorescence enhancement in silver doped silica based nanobiomaterials

The sol-gel derived silica spheres with surfaces modified by silver nanoparticles were used to enhance the emission efficiency of PDTphotosensitizer Photolon. Two various materials with different Ag concentrations were prepared by exploiting the Tollen's method. The silica nanoparticles were prepared by modified Stöber synthesis. The diameter of obtained silica spheres was ca. 100nm. These silica spheres we used as a carrier for noble nanoparticles, since they can be easily doped by various substances that can change their physical and chemical properties. The colloidal water solutions of Ag-doped SiO2 particles have been prepared. It was demonstrated that the fluorescence intensity of Photolon is influenced by silver nanoparticles concentration, however it is not proportional to the silver concentration. The fluorescence intensity of Photolon with silver doped silica nanoparticles is much higher then fluorescence intensity of Photolon in water solution. This result is very promising and may be used to enhance the photodynamic effect.

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The authors thank dr Jerzy Kowalczyk from Polish Academy of Sciences in Wrocław for his technical and support. The work was supported by the Polish Ministry of Education and Scientific Research, Grant No. N N518 327335.