Execution of julolidine based derivative as bifunctional chemosensor for Zn2+ and Cu2+ ions: Applications in bio-imaging and molecular logic gate.

A simple julolidine based chemosensor (JT) was designed and synthesized by single condensation step. JT displayed excellent selectivity and sensitivity with on-off responses towards Zn2+ and Cu2+ over other biologically relevant metal ions in aqueous media. Upon addition of Zn2+ ions, JT exhibited a significant blue shift in emission followed by turn-on enhancement while with Cu2+, the fluorescence intensity of JT was completely vanished. The 1:1 binding affinity between JT and Zn2+/Cu2+ was proposed by Job's plot analysis. The detection limit for Zn2+ and Cu2+ ions reached at 3.5 × 10-8 M and 1.46 × 10-6 M, respectively. The sensing mechanism of JT with Zn2+/Cu2+ was supported by DFT calculations. Based on photophysical studies and its reversibility environment with EDTA, molecular logic gates were fabricated. Furthermore, JT was successfully established to detect intracellular Zn2+ ions in live cells by turn-on response.