Luminescence spectroscopy

ОFluorescent spectroscopy differ from other spectroscopic techniques because of the recorded spectral dependence is a function of two variables - the excitation wavelength λex and emission wavelength λem. If λex is kept constant and λem is scanned, the measured luminescence spectrum is emission (spectral dependence of the luminescent intensity on the wavelength). If you are scanning λex at constant λem, you measure excitation spectrum (spectral dependence of the excitation efficiency on the excitation wavelength).

Luminescence methods include studies using fluorescence and phosphorescence. Fluorescent measuring are the most widely used as methods for analysis and monitoring of chemical and biochemical reactions and kinetic studies for the fast reactions of electron-excited molecules.

Applications of luminescence spectroscopy for analytical purposes embrace identification of substances, detection of low concentrations of substances, control the changes of studied matter, determination the purity of compounds. Also luminescence studies are used to measure kinetics of conventional chemical reactions. The high sensitivity allows detecting the small degree of substances conversion and sometimes it is possible to establish the mechanism of chemical reaction.

Luminescent methods are used in biology, in particular for the study of protein structure by fluorescent probes and labels. Also they are successfully applied in the study of fast reactions of electronically excited molecules. Such reactions are accompanied by decreasing of fluorescence intensity due to fluorescence quenching. Quenching processes compete with the deactivation of the excited molecules by other mechanisms. Since the fluorescence decay time of about 10-8s, fluorescent methods are commonly used to study the kinetics of fast reactions of excited molecules that occur during a 10-7–10-10s.

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Luminescence spectrum of YVO4:Eu 8 at.% nanopowder (λex = 300 nm)

Overviews and methods

 

Under construction

 

Equipment

Modular spectrofluorometerFluorolog-3

Fluorescence spectrometer Lumina

 

Contacts

The Leading Researcher in optical systems Alexandr Shimko

Specialist in spectrofluorimetry Ilya Kolesnikov

Specialist in spectroscopy and granulometry Anastasia Povolotckaia

Specialist in optical systems Alexandra Mikhaylova