title: Nanofiltering via integrated liquid core waveguides.
abstract: We demonstrate and describe how nanoporous liquid core waveguides can exclude scattering particles, making them an ideal integrated platform for analysis of turbid solutions. Milk with 0.5% fat showed an optical propagation loss of 0.05 dB/mm at 633 nm in nanoporous waveguides compared to the 10.6 dB/mm loss in standard cuvette measurements. To examine the nanofiltering effect, waveguides were infiltrated with solutions containing Rhodamine B molecules (1 nm) and 22 nm red fluorescing polystyrene beads. With fluorescence spectroscopy we show that 22 nm beads are excluded, while Rhodamine B molecules penetrate the waveguides. This is further confirmed by fluorescence microscopy, also revealing a homogenous distribution of Rhodamine in the waveguide volume.
authors: Department of Micro and Nanotechnology, DTU Nanotech, Technical University of Denmark, Kgs. Lyngby, Denmark.
authors: Nimi
authors: N
authors: Gopalakrishnan
authors: Mads Brøkner
authors: MB
authors: Christiansen
authors: Anders
authors: A
authors: Kristensen
mesh_terms: D000818:Animals; D002070:Butadienes / Q000737:chemistry; D020724:Elastomers / Q000737:chemistry; D005374:Filtration / Q000295:instrumentation / Q000379:methods*; D008892:Milk / Q000737:chemistry; D058608:Nanopores; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D055620:Optical Phenomena; D013050:Spectrometry, Fluorescence; D018511:Systems Integration; D014867:Water / Q000737:chemistry
chemical_list: D002070:Butadienes; D020724:Elastomers; D014867:Water; C028834:polybutadiene