Quantification of the Depolarization and Anisotropy of Fluorophore Stokes-Shifted Fluorescence, On-Resonance Fluorescence, and Rayleigh Scattering
| Autor: | Dongmao Zhang, Kumudu Siriwardana, Shengli Zou, Buddhini C. N. Vithanage |
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| Rok vydání: | 2017 |
| Předmět: |
Photon
Fluorophore Physics::Medical Physics 02 engineering and technology 010402 general chemistry 01 natural sciences Resonance (particle physics) Molecular physics Fluorescence spectroscopy Analytical Chemistry Quantitative Biology::Subcellular Processes symbols.namesake chemistry.chemical_compound Optics Rayleigh scattering Physics::Biological Physics Quantitative Biology::Biomolecules Chemistry business.industry Scattering 021001 nanoscience & nanotechnology Fluorescence 0104 chemical sciences Quantitative Biology::Quantitative Methods Resonance fluorescence symbols 0210 nano-technology business |
| Zdroj: | Analytical Chemistry. 89:6686-6694 |
| ISSN: | 1520-6882 0003-2700 |
| DOI: | 10.1021/acs.analchem.7b00907 |
| Popis: | Fluorophores are important but optically complicated photonic materials as they are simultaneous photon absorbers, emitters, and scatterers. Existing studies on fluorophore optical properties have been focused almost exclusively on its photon absorption and Stokes-shifted fluorescence (SSF) with scant information on the fluorophore photon scattering and on-resonance fluorescence (ORF). Presented herein is a unified theoretical framework and experimental approach for quantification of the fluorophore SSF, ORF, and scattering depolarization and anisotropy using a combination of fluorophore UV-vis, fluorescence emission, and resonance synchronous spectroscopic spectral measurements. A mathematical model for calculating fluorophore ORF and scattering cross sections has been developed that uses polystyrene nanoparticles as the external reference. The fluorophore scattering cross section is ∼10-fold smaller than its ORF counterparts for all the six model fluorophores, but more than 6 orders of magnitude larger than the water scattering cross section. Another finding is that the fluorophore ORF has a depolarization close to 1, while its Rayleigh scattering has zero depolarization. This enables the experimental separation of the fluorophore ORF and photon scattering features in the fluorophore resonance synchronous spectra. In addition to opening a new avenue for material characterization, the methods and insights derived from this study should be important for developing new analytical methods that exploit the fluorophore ORF and photon scattering properties. |
| Databáze: | OpenAIRE |
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