How do you quench fluorescence?

Abstract. Fluorescence quenching refers to any process that decreases the fluorescence intensity of a sample. A variety of molecular interactions can result in quenching. These include excited-state reactions, molecular rearrangements, energy transfer, ground-state complex formation, and colli-sional quenching.

What are fluorophores used for?

Fluorophores (or fluorochromes) are commonly used in conjugation with antibodies as detection reagents in applications such as flow cytometry. Fluorophores can absorb and emit light within a range of wavelengths, normally referred to as the absorbance (excitation) and emission spectra.

What affects fluorescence intensity?

Three important factors influencing the intensity of fluorescence emission were theoretical analyzed, including the absorption ability of excitation photons, fluorescence quantum yield, and fluorescence saturation & fluorescence quenching.

What happens in 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.

What is aggregation caused quenching?

Aggregation-caused quenching (ACQ) is a known phenomenon responsible for low emission of dyes when in the form of solid state (e.g. in nanostructures, nano-precipitates), although in solution (in appropriate solvent) these are characterized with bright emission [27,28].

How long does fluorescence last?

Since the fluorophore is unstable at high-energy configurations, it eventually adopts the lowest-energy excited state, which is semi-stable. The length of time that the fluorophore is in excited states is called the excited lifetime, and it lasts for a very short time, ranging from 10-15 to 10-9 seconds.

How does quenching of fluorescence occur at the molecular level?

Surat P, Ph. D. 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 does a fluorophore fluorescence?

The mechanism of fluorescence Fluorescent molecules, also called fluorophores or simply fluors, respond distinctly to light compared to other molecules. As shown below, a photon of excitation light is absorbed by an electron of a fluorescent particle, which raises the energy level of the electron to an excited state.

How does fluorescence quenching work?

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.