What is the natural lifetime of fluorescein?
Historically, one of the first measurements of the fluorescence lifetime of organic molecules was conducted via polarization studies, as demonstrated by F. Perrin, who determined the fluorescence lifetime of fluorescein with a remarkable accuracy of 4.3 ns46 (the current value is 4.0 ns54).
What is ICG fluorescence?
ICG is a tricarbocyanine dye which fluoresces, i.e. emits light, after excitation under near-infrared light at 806 nm light. ICG is highly soluble in water and binds to β-lipoproteins, particularly to albumin. Because of the high protein content of lymph, ICG accumulates in the lymphatic pathways and lymph nodes.
Is indocyanine green contrast?
Nanoparticles 100 nm in diameter containing indocyanine green (ICG) have been developed as a contrast agent for photoacoustic (PA) imaging based on (photonic explorers for biomedical use by biologically localized embedding PEBBLE) technology using organically modified silicate (ormosil) as a matrix.
What determines fluorescence lifetime?
It is based on the fact that the fluorescence lifetime of a fluorophore depends on its molecular environment but not on its concentration. It can be applied in fluorescence microscopy where the local probe concentration cannot be controlled.
How do you calculate fluorescence decay?
The fluorescence lifetime τ corresponds to the average time a fluorophore stays in its excited state is given by τ = 1 / k f + k nr with kf the radiative decay and knr the nonradiative decay rate.
How long does ICG last?
Because of the plasma protein binding, ICG stays for up to 20 to 30 minutes in the vessels (intravasally). When the eye is examined, it thus stays for a long time in tissues with a higher blood flow, such as the choroid and the blood vessels of the retina.
How long does indocyanine green stay in your system?
After being injected, indocyanine green (ICG) stays in the tissues for up to 20 to 30 minutes. This longer duration is because ICG binds tightly to plasma proteins, which confines it to the vascular system. ICG stays longer in tissues with higher blood flow, such as the blood vessels of the retina and the choroid.
How long does Indocyanine Green stay in your system?
How do you get lifetime fluorescence?
What is decay time in luminescence?
The luminescence intensity of the 1.681 eV silicon-related system initially decreases relatively slowly, followed, after about 3 ns, by a rapid decrease with decay time of 2.4 ± 0.3 ns. This behaviour is attributed to the presence of energy reservoirs coupled to the 1.681 eV excited state.
How do you dissolve an ICG?
Shake the ICG vial gently to dissolve. After reconstitution, a 25 mg vial of ICG contains 2.5 mg of dye per mL of solution, so a 1.0 mL injection contains a 2.5 mg dose of ICG. Indocyanine Green for Injection, USP must be used within 6 hours after reconstitution. If a precipitate is present, discard the solution.
What is Indocyanine Green made of?
Indocyanine Green Description Indocyanine Green for injection USP is a sterile, lyophilized green powder containing 25 mg of Indocyanine Green with no more than 5% sodium iodide. It is packaged with Sterile Water for injection, USP used to dissolve the Indocyanine Green.
How is ICG metabolized?
The ICG is not metabolized; it does not undergo enterohepatic recirculation. Thus, ICG excretion rate in bile reflects the hepatic excretory function and hepatic energy status.
Is indocyanine green nephrotoxic?
The most widely adopted reagent for NIRF in urologic surgery is the fluorescent dye, indocyanine green (ICG). ICG is non-nephrotoxic, excreted exclusively by the liver, with inci- dences of minor and major complications being exceedingly rare [1].
What is phosphorescence lifetime?
The phosphorescence lifetime is defined as the average time that a molecule remains in an excited state prior to returning to the ground state by emitting a photon.
What is photoluminescence lifetime?
The fluorescence (or more generally the photoluminescence) lifetime is an intrinsic characteristic of a luminescent species that can provide insight into the species excited state dynamics.
What affects fluorescence lifetime?
It is affected by external factors, such as temperature, polarity, and the presence of fluorescence quenchers. Fluorescence lifetime is sensitive to internal factors that are dependent on fluorophore structure.
Why does phosphorescence last longer than fluorescence?
The reason phosphorescence lasts longer than fluorescence is because the excited electrons jump to a higher energy level than for fluorescence. The electrons have more energy to lose and may spend time at different energy levels between the excited state and the ground state.
What is indocyanine green?
1 Introduction Indocyanine green (ICG) as a fluorescent agent has been widely used in biomedical fields since its introduction.1–5ICG has attractive features of very low toxicity and high absorptance in a wavelength range of 600 to 900 nm, which is a relatively transparent window for biological tissues.
What is the emission and absorption properties of indocyanine green in Intralipid solution?
Emission and absorption properties of indocyanine green (ICG) in Intralipid solution have been investigated. The study is focused on relatively low ICG concentration at a range of 0 to 20 μM. A diffusion model was used to analyze the emission properties of ICG solution at different concentrations.
What is the fluorescence lifetime of ICG in water?
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).