A chemosensor showing discriminating fluorescent response for highly selective and nanomolar detection of Cu²âº and Zn²âº and its application in molecular logic gate.

A fluorescent based receptor (4Z)-4-(4-diethylamino)-2-hydroxybenzylidene amino)-1,2dihydro-1,5-dimethyl-2-phenylpyrazol-3-one (receptor 3) was developed for the highly selective and sensitive detection of Cu(2+) and Zn(2+) in semi-aqueous system. The fluorescence of receptor 3 was enhanced and quenched, respectively, with the addition of Zn(2+) and Cu(2+) ions over other surveyed cations. The receptor formed host-guest complexes in 1:1 stoichiometry with the detection limit of 5 nM and 15 nM for Cu(2+) and Zn(2+) ions, respectively. Further, we have effectively utilized the two metal ions (Cu(2+) and Zn(2+)) as chemical inputs for the manufacture of INHIBIT type logic gate at molecular level using the fluorescence responses of receptor 3 at 450 nm.

Design and Synthesis of a Pyridine Based Chemosensor: Highly Selective Fluorescent Probe For Pb2+

A pyridine based imine-linked chemosensor has been synthesized and evaluated its binding affinity with library of transition metal ions. It has prominent selectivity towards Pb2+ among other metal ions in DMF/H2O (9:1, v/v) solvent system. The 1:1 stoichiometric was confirmed by job's plot and has a binding constant (Ka) = 5.142 × 103 M-1 on fluorescence. A B3LYP/6-31G and B3LYP/LanL2DZ basis sets were employed for optimization of 3 and 3.Pb2+.

Bis(2-hydroxy-3-isopropyl-6-methyl-benzaldehyde)ethylenediamine: a novel cation sensor.

Novel substituted phenol-based new symmetrical bis(2-hydroxy-3-isopropyl-6-methyl-benzaldehyde)ethylenediamine (1) has been designed and synthesized. The compound 1 fluorometrically recognized Cu(2+) ion in CH3OH/H2O (90:10, v/v) by exhibiting an increase in emission upon complexation. In addition, Cu(2+) gave rise to a change in colour of the solution of compound 1, which was clearly visible to the naked eye under UV irradiation. The association constant (K) of compound 1 with Cu(2+) ion was computed with the Benesi-Hildebrand plot and Scatchard plot at 43,000 M(-1) and 43,011 M(-1) respectively.