title: Wavelength-resolved measurements of fluorescence lifetime of indocyanine green.
abstract: We study fluorescence lifetime of indocyanine green (ICG) using femtosecond laser and sensitive detection based on time-correlated single-photon counting. A time-resolved multichannel spectral system is constructed and applied for determination of the fluorescence lifetime of the ICG in different solvents. Emission properties of ICG in water, milk, and 1% intralipid solution are investigated. Fluorescence of the fluorophore of different concentrations (in a range of 1.7-160 μM) dissolved in different solutions is excited by femtosecond pulses generated with the use of Ti:Sa laser tuned within the range of 740-790 nm. It is observed that fluorescence lifetime of ICG in water is 0.166 ± 0.02 ns and does not depend on excitation and emission wavelengths. We also show that for the diffusely scattering solvents (milk and intralipid), the lifetime may depend on the dye concentration (especially for large concentrations of ICG). This effect should be taken into account when analyzing changes in the mean time of arrival of fluorescence photons excited in ICG dissolved in such optically turbid media.
authors: Polish Academy of Sciences, Institute of Biocybernetics and Biomedical Engineering, Trojdena 4, 02-109 Warsaw, Poland. anna.gerega@ibib.waw.pl
authors: Anna
authors: A
authors: Gerega
authors: Norbert
authors: N
authors: Zolek
authors: Tomasz
authors: T
authors: Soltysinski
authors: Daniel
authors: D
authors: Milej
authors: Piotr
authors: P
authors: Sawosz
authors: Beata
authors: B
authors: Toczylowska
authors: Adam
authors: A
authors: Liebert
mesh_terms: D000818:Animals; D016009:Chi-Square Distribution; D004655:Emulsions / Q000737:chemistry; D005456:Fluorescent Dyes / Q000737:chemistry*; D007208:Indocyanine Green / Q000737:chemistry*; D008856:Microscopy, Fluorescence / Q000379:methods*; D008892:Milk / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry; D013024:Soybean Oil / Q000737:chemistry; D013997:Time Factors
chemical_list: D004655:Emulsions; D005456:Fluorescent Dyes; D010743:Phospholipids; C545823:soybean oil, phospholipid emulsion; D013024:Soybean Oil; D007208:Indocyanine Green