Schiff Base Functionalized 1,2,4-Triazole and Pyrene Derivative for Selective and Sensitive Detection of Cu2+ ion in the Mixed Organic- Aqueous Media.

We have prepared Schiff base functionalized 1,2,4-triazole and pyrene derivative for selective, sensitive, and naked eye colorimetric detection of Cu2+ in the mixed organic- aqueous media. Amongst the 18 different metal ions studied for absorption and fluorescence titration, only Cu2+ ion encourages the modification in spectral properties of Schiff base functionalized 1,2,4-Triazole and Pyrene Probe. The stoichiometric ratio of the TP-Cu2+ complex was determined to be 2:1 according to Job's plot. The lower detection limit estimated for Cu2+ is 0.234 nM which shows excellent sensitivity and selectivity of the present analytical method towards detection of Cu2+ ion in the mixed organic-aqueous media. The present approach has been successfully utilized for the quantitative determination of Cu2+ ion from environmental aqueous solution.

The first tryptophan based turn-off chemosensor for Fe2+ ion detection.

In this research work, we have designed and synthesized a novel Tryptophan-Quinoline conjugated turn-off chemosensor 4 for the selective detection of Fe2+ ion with high sensitivity (3.06 µM) among 21 metal cations such as Ag+, Ca+, Cs+, Cu+, K+, Na+, NH4+, Ba2+, Ca2+, Cd2+, Co2+, Cu2+, Mn2+, Ni2+, Pb2+, Zn2+, Al3+, Au3+, Cr3+ and Fe3+ in DMF-HEPES (1 mM, pH = 7.0, 1:1, v/v) aqueous-organic solvent system. It showed a fluorescence quenching mechanism through the blocked PET process. The optical properties, binding mode of the metal ion with the receptor, plausible electron transfer mechanism, and its practical applications have been discussed. This work will open up a new avenue in amino acid-based Fe2+ ion sensors.