Sensors proton transfer

Fig. 3. Working principle of sensor proton-transfer coupling reverse PET, on-off.

Klymchenko AS, Demchenko AP (2002) Electrochromic modulation of excited-state intramolecular proton transfer the new principle in design of fluorescence sensors. J Am Chem Soc 124 12372-12379... 

Depending on the photophysical properties the pH fluorescent sensors can be divided into three classes (1) chemosensors that undergo photoinduced proton transfer, (2) chemosensors that undergo photoinduced electron transfer, and (3) those sensors that undergo neither proton nor electron transfer. 

The last group of fluorescent sensors is based on neither photoinduced proton transfer nor photoinduced electron transfer. The best-known example of this kind of molecular device is fluorescein (Figure 16.2e). The evolution of the fluorescence spectrum versus pH should be similar to that of the absorption spectrum. In other words, when increasing the pH, the absorption and emission bands of the acidic form should decrease with a concomitant increase in the absorption and emission bands of the basic form [1],... 

L0kke, M. M., Edelenbos, M Larsen, E., Feilberg, A. (2012) Investigation by real time proton transfer reaction-mass spectrometry (PTR-MS) of volatiles emitted from freshly cut onions Allium cepa L.). Sensors 12, 16060. 

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