title: Determination of the size, concentration, and refractive index of silica nanoparticles from turbidity spectra.
abstract: The size and concentration of silica cores determine the size and concentration of silica/gold nanoshells in final preparations. Until now, the concentration of silica/gold nanoshells with Stober's silica core has been evaluated through the material balance assumption. Here, we describe a method for simultaneous determination of the average size and concentration of silica nanospheres from turbidity spectra measured within the 400-600 nm spectral band. As the refractive index of silica nanoparticles is the key input parameter for optical determination of their concentration, we propose an optical method and provide experimental data on a direct determination of the refractive index of silica particles n = 1.475 +/- 0.005. Finally, we exemplify our method by determining the particle size and concentration for 10 samples and compare the results with transmission electron microscopy (TEM), atomic force microscopy (AFM), and dynamic light scattering data.
authors.affiliation: Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prospekt Entuziastov, Saratov, Russia.
authors.forename: Boris N
authors.initials: BN
authors.lastname: Khlebtsov
authors.forename: Vitaly A
authors.initials: VA
authors.lastname: Khanadeev
authors.forename: Nikolai G
authors.initials: NG
authors.lastname: Khlebtsov
mesh_terms: D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D012822:Silicon Dioxide