What is luminescence lifetimes?
What is luminescence lifetimes?
The luminescence lifetime is the time required for the energy of a population of excited fluorophores to decrease to 1/e of the maximum intensity via energy loss through luminescence (fluorescence or phosphorescence) and other nonradiative processes.
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.
What causes fluorescence quenching?
Fluorescence quenching is a physicochemical process that lowers the intensity of emitted light from fluorescent molecules. When a molecule absorbs light, electrons in its constituent atoms become excited and are promoted to a higher energy level.
How long is fluorescence lifetime?
Principles. The fluorescence lifetime is a measure of the time a fluorophore spends in the excited state before returning to the ground state by emitting a photon [1]. The lifetimes of fluorophores can range from picoseconds to hundreds of nanoseconds.
What is fluorescence intensity?
The fluorescence intensity indicates how much light (photons) is emitted. It is the extent of emission and it depends on the concentration of the excited fluorophore. Fluorescence is created by the absorption of energy (light) by fluorescent molecules, called fluorophores.
What is the difference between fluorophore and fluorochrome?
Yes, fluorophore and fluorochrome refer to the same thing. Fluorophores, or fluorochromes, are fluorescent chemical compounds that are capable of absorbing light from a laser and re-emitting the light within a range of wavelengths upon excitation.
What is FITC and PE?
The FITC / PE Compensation Standard is to be used in conjunction with hardware or software to remove spectral overlap from fluorochromes into secondary fluorescence detectors of a flow cytometer. Flow cytometers are designed to have a primary detector for each fluorochrome label (e.g. FL1 – FITC, FL2 – PE, FL3 – Cy™5).
What are the two types of quenching?
There are two different ways of quenching: static and dynamic quenching.
What are the types of quenching?
There are ten quenching methods in the heat treatment process, which are:
- single-medium (water, oil, air) quenching;
- interrupted quenching;
- martempering;
- martempering below MS point;
- isothermal quenching of bainite;
- compound quenching;
- precooled isothermal quenching;
- delayed cooling quenching;
What is the formula of fluorescence?
The fluorescence quantum yield ((\Phi\)) gives the efficiency of the fluorescence process. It is the ratio of photons emitted to photons absorbed. [S1] is the concentration of excited state molecules at time t, [S1]0 is the initial concentration and τ is the decay rate.
What is difference between fluorescence and luminescence?
The main difference between fluorescence and luminescence is that luminescence describes any process where photons are emitted without heat being the cause, whereas fluorescence is, in fact, a type of luminescence where a photon is initially absorbed, which causes the atom to be in an excited singlet state.