fluorezierender

Fluorezierender is an adjective used in chemistry, physics and biology to describe substances or states that emit light (fluorescence) after being excited by electromagnetic radiation. The fluorescence process typically involves absorption of a photon by a molecule, promotion to an excited electronic singlet state, rapid relaxation to the lowest vibrational level of that state, and emission of a photon as it returns to the ground state. The emitted light has a longer wavelength than the absorbed light, a phenomenon known as the Stokes shift. Fluorescence is distinguished from phosphorescence by the involvement of singlet states and usually occurs without a detectable delay.

Key parameters include quantum yield, the fraction of excited molecules that emit photons, and photostability, or resistance to photobleaching. The excitation spectrum and emission spectrum describe the wavelengths that can excite the material and the light it emits. Fluorezierende substances can be organic dyes, fluorescent proteins, quantum dots, or certain inorganic phosphors. Common examples include fluorescein, rhodamine dyes, GFP and mCherry, as well as quantum dots and rare-earth doped materials.

Applications span science and industry. In biology and medicine they enable fluorescence microscopy, flow cytometry, and biosensing; in materials science they are used for lighting, security inks and sensors. Detection typically employs fluorescence microscopes or spectrofluorimeters, with detectors such as photomultiplier tubes or CCD/CMOS cameras and optical filters to isolate excitation and emission bands.

Limitations include photobleaching, potential phototoxicity for living samples, and environmental or health concerns for certain compounds. Proper handling, disposal and adherence to safety data are important. The concept has historical roots in the work of George Gabriel Stokes in the 19th century, who described the basic principle of fluorescence.