The centenary of the Stern-Volmer equation of fluorescence quenching: From the single line plot to the SV quenching map

In the year of 2019, we celebrate the centenary of the publication of the remarkable paper by Otto Stern and Max Volmer concerning the kinetics analysis of fluorescence quenching. Their achievement changed enormously many fields of science with great impact in the studies of electronic spectroscopy and kinetics of organic, inorganic and biological compounds in condensed phase. The development of molecular photochemistry was in great part based on the use of the Stern-Volmer (SV) approach to investigate bimolecular interaction in the electronic excited-state. This paper reviews and summarizes the assumptions behind the Stern-Volmer equation and the extensions of the theory to other important situations. Discussions about the use of the SV approach to investigate probe and quencher distribution, association, diffusion and reaction at the molecular level obtained from advanced fluorescence microscopy methods are also included.