Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence that occurs in gas, liquid, or solid chemical systems/Spectroscopy/Electronic_Spectroscopy/Radiative_Decay/Fluorescence). Fluorescence is the phenomenon of absorption of electromagnetic radiation, typically from ultraviolet or visible light, by a molecule and the subsequent emission of a photon of a lower energy (smaller frequency, longer wavelength) . This causes the light that is emitted to be a different color than the light that is absorbed. Stimulating light excites an electron to an excited state. When the molecule returns to the ground state, it releases a photon, which is the fluorescent emission.
Some key points about fluorescence include:
- Fluorescence is simply defined as the absorption of electromagnetic radiation at one wavelength and its reemission at another, lower energy wavelength.
- The specific frequencies of excitation and emission are dependent on the molecule or atom/Spectroscopy/Electronic_Spectroscopy/Radiative_Decay/Fluorescence).
- Generally, molecules that fluoresce are conjugated systems/Spectroscopy/Electronic_Spectroscopy/Radiative_Decay/Fluorescence).
- The glow of fluorescence stops right after the source of excitatory radiation is switched off.
- Fluorescence is often used to analyze molecules, and the addition of a fluorescing agent with emissions in the blue region can be used to detect the presence of proteins, DNA, and other biological molecules.
