A simple naphthalimide based PET probe for Fe3+ and selective detection of pyrophosphate through displacement approach: Cell imaging studies and logic interpretation

Abstract The present work describes design, synthesis and photophysical behavior of a new molecular fluorescent probe 5. The probe 5 upon interaction with different metal ions in phosphate buffer (THF:H2O; 1:99, v/v; pH 7.2) exhibited enhanced emission (turn–On) with Fe3+ (LOD = 1.05 × 10−9 M) selectively due to the formation of an ensemble, 5.Fe3+. On the other hand the interaction of ensemble 5.Fe3+ with different class of anionic species fluorescence quenching (turn–Off) was observed with pyrophosphate ions (PPi) (LOD = 4.2 × 10-7 M) selectively due to the formation of ferricpyrophosphate in the medium. The Off–On–Off emission behavior exhibited by the probe in the presence of Fe3+ and PPi is attributed to PET–Off–On mechanism, respectively. The live cell imaging and in vivo studies in zebra fish suggested about the potential biological application of probe to detect both the ions. The ensemble, 5.Fe3+ has also been tested to detect PPi in DNA polymerase chain reaction (PCR) product. Additionally, the probe upon providing Fe3+ and PPi ions as chemical inputs sequentially mimic “write-read-erase-read” functions through the formation of an INHIBIT gate.