Smart PET based organic scaffold exhibiting bright “Turn–On” green fluorescence to detect Fe3+ ion: Live cell imaging and logic implication

Abstract

An efficient and simple photoinduced electron transfer (PET) based fluorescence turn–On probe 7 has been designed and synthesized by bridging naphthalimide and thiophene moieties through a piperazine unit. The photophysical behavior of probe and its affinity toward different metal ions have been investigated in partial aqueous medium, protein medium and live cells. The probe exhibited fluorescence “turn-On” response for Fe3+ ion with high sensitivity (limit of detection 0.373 μM) and selectively along with naked-eye sensitive visible green color in the medium. The significant change in photophysical behavior of the probe, upon a complexation between probe and Fe3+ is attributed to restriction in PET process. The probe 7 showed excellent biocompatibility and has been utilized in cellular imaging experiment to detect Fe3+ in MCF-7 live cells. Also, at molecular level probe 7 mimics the functions of a sequential logic circuit, corresponding to a memory device in which the two inputs (Fe3+ and AcO−) based sequential logic operations mimic the function of a memory element.