Perylene based PET fluorescent molecular probes for pH monitoring

New perylene-based pH probes have been synthesized and utilized for the development of pH optodes. These amine-functionalized perylene-based probes display high molar absorption coefficients in the visible range and protonated forms are characterized by fluorescence quantum yields close to unity. By deprotonation, a strong fluorescence quenching occurs due to an efficient PET-type mechanism. These molecules have been immobilized in two types of polymer (PVA-GA and HydroMed D4). Photophysical studies of these materials revealed heterogeneity in the distribution of the molecules inside the polymer matrix. Finally, optodes have been developed for the measurement of pH between 8 and 10 with promising photostability and sensibility results.