Zn2+ ion responsive fluorescent chemosensor probe of Thiophene-diocarbohydrazide derivatives

A new fluorescent probe of Thiophene- dicarbohydrazide based chemosensor synthesized for Zn2+ ion detection and investigated well. It was found that the chemosensor highly emissive when its complexation with Zn2+ ion. This turn-on fluorescence recognition was premeditated in DMSO/H2O (6:4 v/v) medium. The binding constant was calculated and it found to be 1.15 x 10(4) M-1. The limit of detection (LOD) was calculated to be 1.51 x 10(-7) M which is well below the permissible level of Zn2+ (70 mu M) in drinking water. The 1:1 binding stoichiometry of the chemosensor HNTCH-Zn2+ complex was intended from Jobs' plot. The observed fluorescent enhancement turn-on emission can be delineated by chelation enhanced fluorescence mechanism. The reversibility and INHIBIT/IMPLICATION Logic gate behaviour were performed for HNTCH-Zn2+ complex with EDTA accordingly.