A Coumarin-Based Luminescent Chemosensor for Recognition of Cu2+ and its In-Situ Complex for CN- Sensing via Cu2+ Displacement Approach.

A new coumarin based chemosensor has been developed for selective fluorescent recognition of Cu2+ in MeOH/H2O (4:1, v/v at pH = 7.2 aqueous solution) medium with 1:1 binding stoichiometry. The in-situ prepared Cu2+ complex displays high selectivity towards CN- via Cu2+ displacement approach with detection limit in the micro molar range. Moreover, in presence of Cu2+, the receptor exhibits reversible emission change with EDTA and thus offers an interesting property of molecular 'IMPLICATION' logic gate with Cu2+ and EDTA as chemical inputs.

A Reversible Pyrene-based Turn-on Luminescent Chemosensor for Selective Detection of Fe(3+) in Aqueous Environment with Logic Gate Application.

A new Schiff-base, HL luminescent chemosensor of 1-amino pyrene and 8-hydroxy quinoline-2-carboxaldehyde was synthesized which demonstrates selective fluorimetric detection of Fe(3+) in aqueous medium with detection limit of 2.52 × 10(-8) M. The receptor shows selective 'turn-on' response towards Fe(3+) over other metal ions. This gradual 'turn-on' fluorescence response for Fe(3+) may be induced via CHEF (chelation-enhanced fluorescence) through close proximity of pyrene rings. The stoichiometry and binding property of HL with Fe(3+) was examined by emission studies. In presence of Fe(3+), HL also exhibits reversible change in emission pattern with EDTA and thus offers an interesting property of molecular 'INHIBIT' logic gate with Fe(3+) and EDTA as chemical inputs.