Highly Selective Detection of Cr Ion with Colorimetric & Fluorescent Response Via Chemodosimetric Approach in Aqueous Medium.

So far, very few numbers of chemosensors for Cr ion have been reported. However, the main drawback of reported receptors are the lack of selectivity and other trivalent cations such as Fe, Al and anions like F and OAc frequently interfere with such assays. This paper present the synthesis, characterization & sensor studies of Schiff base containing naphthalene moiety which selectively detect Cr ion by chemodosimetric approach. Using FT-IR, H NMR, C NMR and ESI mass spectroscopic techniques the probe was characterized. This receptor exhibit more selectivity and sensitivity towards Cr than other divalent and trivalent cations like Mn, Zn, Co, Ni, Cd, Cu, Hg, Fe, and Al ions. After the addition of chromium ion the receptor get change from yellow to colorless in aqueous medium. But no color change was observed on the addition of other metal ions. Using UV-Vis and PL studies, it was confirmed that the selective hydrolysis of imine group of receptor by Cr ions takes place with high fluorescence enhancement that is corresponding to 1-naphthylamine. Receptor acts as selective chemodosimeter for Cr ions with 2:1 stoichiometry and micro molar detection limit. This chemodosimetric approach was applied successfully for bio-imaging of HeLa cells.