PET modulated fluorescent sensing from the BF2 chelated azadipyrromethene platform

A convergent building block synthesis has been applied to new off/on photoinduced electron transfer ( PET) modulated fluorescent sensors which are based on a BF2 chelated tetraarylazadipyrromethene platform and operate in the biomedically important red region of the visible spectrum. Incorporation of diethylamine and morpholine receptors facilitates off/on microenvironment polarity and pH sensing. Aqueous formulation and in vitro cellular imaging demonstrates their potential for intracellular sensing.