Development of fluorinated naphthofluoresceins for Cerenkov imaging

•Electrophilic fluorination of naphthofluorescein (NF) resulted in mono-, di- and trifluorinated derivatives.•Optical and chemical characterization of products shows bathochromic and acidic shifts in pKa with increasing fluorination.•NF, 4-MFNF and 4,10-DFNF can distinguish pH in a biologically-relevant range using Selective Bandwidth Quenching.•Measurements of pH using Cerenkov Radiation Energy Transfer (CRET) are possible with NF; not with 4-MFNF and 4,10-DFNF.•Quantum yield of fluorescence shown to be decreased due to fluorination of NF.