A new selective fluorescent probe for lead ions

A new fluorescent probe (BPb1) for Pb2+ has been synthesized, where diethanolamine (receptor) is linked with 4,4-difluoro-4-bora-3a, 4a-diaza-s-indacene (BODIPY) (fluorophore) via a methylene group (spacer). The absorption (496 nm) and emission (505 nm) wavelengths are in visible range. The fluorescence quantum yields of the lead-free and lead-bound states of BPb1 in acetonitrile are 0.013 and 0.693, respectively. The large chelation enhanced fluorescence effect (CHEF) with Pb2+ can be explained by the blocking of the photoinduced electron transfer (PET) process.