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Time-resolved fluorescence spectroscopy is an extension of fluorescence spectroscopy. Here, the fluorescence of a sample is monitored as a function of time after excitation by a flash of light. The time resolution can be obtained in a number of ways, depending on the required sensitivity and time resolution:
This method (commonly referred to as time-resolved fluorometry or TRF) involves two fluorophores: a donor and an acceptor. Excitation of the donor fluorophore (in this case, the lanthanide ion complex) by an energy source (e.g. flash lamp or laser) produces an energy transfer to the acceptor fluorophore if they are within a given proximity to ...
In time resolved fluorometry the fast photomultiplier tube is the only practical single photon detector. Good single photon resolution is also an advantage in counting photons from long decay fluorescent probes, such as lanthanide chelates. [4] These commercial instruments are available in the market today: Perkin-Elmer Micro Filter Fluorometer ...
Fluorescence lifetimes can be determined in the time domain by using a pulsed source. When a population of fluorophores is excited by an ultrashort or delta pulse of light, the time-resolved fluorescence will decay exponentially as described above. However, if the excitation pulse or detection response is wide, the measured fluorescence, d(t ...
Fluorescence spectroscopy (also known as fluorimetry or spectrofluorometry) is a type of electromagnetic spectroscopy that analyzes fluorescence from a sample. It involves using a beam of light, usually ultraviolet light , that excites the electrons in molecules of certain compounds and causes them to emit light; typically, but not necessarily ...
Jablonski diagram of FRET with typical timescales indicated. The black dashed line indicates a virtual photon.. Förster resonance energy transfer (FRET), fluorescence resonance energy transfer, resonance energy transfer (RET) or electronic energy transfer (EET) is a mechanism describing energy transfer between two light-sensitive molecules (chromophores). [1]
YFP sensitivity to these small anions results from ground-state binding near the chromophore, [3] which apparently alters the chromophore ionization constant and hence the fluorescence emission. The fluorescence of YFP is sensitive to [Cl −] and pH. The effect is fully reversible. YFP is excited at visible range and is a genetically encoded ...
Some continuous glucose monitors are commercially available, but suffer from the severe drawback of a short working life of the probe. The majority of these work amperometrically. As a result, there is an effort to create a sensor that relies on a different mechanism, such as via external infrared spectroscopy or via fluorescent biosensors. [3]