Photophysics, mechanistic studies and biosensing capability of pyridinium and isoquinolinium betaines

Environmentally sensitive molecules have a wide range of applications, including as sensors or imaging agents for biological processes. One way this can be achieved is by measuring changes of fluorescence (variation in the colour of light emitted). This work describes the synthesis of such materials and several studies used to elucidate the underlying mechanisms responsible for their sensitive behaviour. As an application, one of these molecules was tethered to a known drug and used to test sensing capability on binding to a cell membrane-embedded protein receptor.