A novel ratiometric fluorescent Fe3+ sensor based on a phenanthroimidazole chromophore.

Abstract Phenanthroimidazole derivative 1 has been developed as a rare example of ratiometric fluorescent sensors for Fe 3+ . Interestingly, upon treatment with Fe 3+ , the sensor displayed a ratiometric fluorescent response with an enhancement of the ratios of emission intensities at 440 and 500 nm from 0.36 to 3.24. The detection range of the sensor for Fe 3+ is in the 1.0 × 10 −5 –1.5 × 10 −4  M concentration range and the detection limit is 5.26 × 10 −6  M. In addition, the sensor showed good selectivity to Fe 3+ with the selectivity coefficients ( K F e 3+ = S F e 3+ / S 0 ) of Fe 3+ over other metal ions tested in the range of 5–68.