What is the relationship between temperature and fluorescence in fluorometric measurements?

In fluorometric measurements, higher temperatures typically lead to a reduction in fluorescence intensity. This occurs due to several factors. As the temperature increases, the molecular movements of the fluorescent molecules also increase. This increased kinetic energy can enhance non-radiative decay processes (like vibrational relaxation), which means that absorbed energy is dissipated as heat rather than being re-emitted as fluorescent light. Consequently, the efficiency of fluorescence decreases.

Furthermore, increased temperature may also lead to a phenomenon known as quenching, where the likelihood of energy transfer processes that compete with fluorescence increases, further reducing the fluorescence signal. Thus, in many cases, an elevation in temperature results in diminished fluorescence, making it an important consideration in any measurement involving fluorometric techniques.