Direct Observation of Acrylamide Fluorescence

Acrylamide is a widely used quenching agent in UV/VIS spectroscopic studies of biopolymers. It is believed to interfere with the chromophore luminescence by electron capture, resonance energy transfer or through collisional deactivation. The agent itself has been presumed optically silent, due to the low magnitude of the lowest UV absorption band. We have postulated that the dynamics of the semi-rigid acrylamide, at room temperature, can provide an efficient dissipative channel of the optical energy. Consequently, by restricting the acrylamide by a glass environment in the 10 - 95 K range, we were able to record flourescence emission and excitation spectra associated with the lowest UV absorption band. This observation, corroborated by the electronic structure calculations, further supports the photon exchange as the mechanism of the acrylamide-induced quenching