Selective and sensitive fluorescence “turn-on” Zn 2+ probes based on combination of anthracene, diphenylamine and dipyrrin

Two fluorescence “turn-on” Zn 2+ probes were developed by introducing an anthracenyl fluorophore through the linkage of a diphenylamino moiety at the 5-position of a dipyrrin moiety. Thus, two compounds with weak fluorescence were designed, synthesized, and employed as CHEF (chelation enhanced fluorescence) type fluorescence “turn-on” Zn 2+ probes, which exhibit dramatic fluorescence enhancement upon addition of Zn 2+ , showing high sensitivities and impressive detection limits of 13 and 12 nM, respectively, better than their analogues containing simple aryl substituents at the 5 positions of a di- or tripyrrin moiety. In addition, both of the probes exhibit good selectivity, short response time of less than 10 s and wide applicable pH ranges. Furthermore, the weak fluorescence nature of the probes was rationalized based on viscosity dependence measurements and theoretical calculations. These results provide further insight into the development of selective and sensitive zinc probes.