title: Acoustically levitated droplets: a contactless sampling method for fluorescence studies.
abstract: Acoustic levitation is used as a new tool to study concentration-dependent processes in fluorescence spectroscopy. With this technique, small amounts of liquid and solid samples can be measured without the need for sample supports or containers, which often limits signal acquisition and can even alter sample properties due to interactions with the support material. We demonstrate that, because of the small sample volume, fluorescence measurements at high concentrations of an organic dye are possible without the limitation of inner-filter effects, which hamper such experiments in conventional, cuvette-based measurements. Furthermore, we show that acoustic levitation of liquid samples provides an experimentally simple way to study distance-dependent fluorescence modulations in semiconductor nanocrystals. The evaporation of the solvent during levitation leads to a continuous increase of solute concentration and can easily be monitored by laser-induced fluorescence.
authors.affiliation: Federal Institute for Materials Research and Testing (BAM), Richard-Willstätter-Str. 11, 12489 Berlin, Germany. jork.leiterer@bam.de
authors.forename: Jork
authors.initials: J
authors.lastname: Leiterer
authors.forename: Markus
authors.initials: M
authors.lastname: Grabolle
authors.forename: Knut
authors.initials: K
authors.lastname: Rurack
authors.forename: Ute
authors.initials: U
authors.lastname: Resch-Genger
authors.forename: Jan
authors.initials: J
authors.lastname: Ziegler
authors.forename: Thomas
authors.initials: T
authors.lastname: Nann
authors.forename: Ulrich
authors.initials: U
authors.lastname: Panne
mesh_terms: D000162:Acoustics; D002625:Chemistry, Organic / Q000379:methods; D004396:Coloring Agents / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry; D049449:Luminescence; D008832:Microchemistry; D008956:Models, Chemical; D053758:Nanoparticles; D036103:Nanotechnology / Q000379:methods; D010316:Particle Size; D045663:Quantum Dots; D012666:Semiconductors; D013050:Spectrometry, Fluorescence / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors; D014465:Ultrasonics
chemical_list: D004396:Coloring Agents; D005456:Fluorescent Dyes