title: On total internal reflection investigation of nanoparticles by integrated micro-fluidic system.
abstract: We report on a novel sensor for characterization of nanoparticles colloidal suspensions. We employ a diffraction grating under total internal reflection for investigation of nanodisperse fluids passing through an integrated microfluidic channel. Dispersions containing polymeric, metallic, and ferromagnetic nanoparticles are studied. Using this device, we can accurately determine in real-time the specific refractive index for the nanoparticle suspension and the nanoparticle concentration. The nanoparticle concentrations can be calculated with a resolution of 0.3-0.5 wt% for polymeric nanoparticles, 0.03-0.05 wt% for metallic nanoparticles, and 0.05-0.1 wt% for ferromagnetic nanoparticles. This translates to an effective refractive index that can be determined with an accuracy of 7 x 10(-4) for the polymeric and 2 x 10(-4) for the metallic and ferromagnetic dispersions.
authors.affiliation: MNES, IMNE, FEI, Technical University of Ilmenau, PF 100565, 98684 Ilmenau, Germany. ysarov@yahoo.com
authors.forename: Yanko E
authors.initials: YE
authors.lastname: Sarov
authors.forename: Ignac
authors.initials: I
authors.lastname: Capek
authors.forename: Tzvetan B
authors.initials: TB
authors.lastname: Ivanov
authors.forename: Katerina Zh
authors.initials: KZh
authors.lastname: Ivanova
authors.forename: Valentina A
authors.initials: VA
authors.lastname: Sarova
authors.forename: Ivo W
authors.initials: IW
authors.lastname: Rangelow
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D008422:Materials Testing / Q000295:instrumentation* / Q000379:methods; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D010783:Photometry / Q000295:instrumentation* / Q000379:methods; D018511:Systems Integration