Quenching of Fluorescence:
Use of the Stern-Volmer Equation
Introduction
Excitation of some chemical compounds when radiated with visible or UV light results in electronic transitions to higher energy levels. The extent to which light of various wavelengths absorbed constitutes the absorption spectrum of the compound.
The spacing between levels in the two electronic states can be measured by either absorption or emission spectroscopy. Emission occurs following an absorption event if the upper state is not relaxed by non-radiative collisional process (called quenching). Dynamic quenching, also called collisional quenching, requires contact between the excited species and the quenching agent (Q). Dynamic quenching occurs as rapidly as the collision partners can diffuse together. The rate is temperature and viscosity dependent. The quencher concentration must be high enough that there is a high probability of collision between the excited species and the quencher during......
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