Ultrafast fluorescence of the chromophore of the green fluorescent protein in alcohol solutions

The ultrafast fluorescence dynamics of solutions of the chromophore responsible for emission from the green fluorescent protein are measured by fluorescence up-conversion. Decays are non-exponential but well fit by a sum of two-exponentials. All decays have a prompt rise time. The two decay times are approximately independent of wavelength, but their weights are wavelength dependent, in a manner consistent with a spectral narrowing with time. The longer decay time has a weak dependence on medium viscosity.