Influence of intermolecular energy transfer on photoacoustic spectra

It is demonstrated that the photoacoustic spectrum of a strongly fluorescing compound which gives a poor photoacoustic response is very sensitive to the presence of another compound with low fluorescence quantum yield. Deliberate addition of such compounds can assist in detection and identification of compounds of low ’’photoacoustic yield.’’ It is also shown that photoacoustic spectroscopy is well suited to the study of energy transfer to acceptor molecules, which have a negligible fluorescence quantum yield.