A Highly Sensitive and Selective Supramolecular Fluorescent Chemosensor for Dichromate Ion Detection and Application to Real Samples

We are reporting here the synthesis, characterization and photophysical properties of a new chemosensor containing triazole heterocycle as binding site for the selective detection of dichromate ion. The fluorescent chemosensor 6 was synthesized using click reaction. The structure of chemosensor 6 was characterized using UV-visible, NMR and mass spectroscopic techniques. Compound 6 displayed extremely high sensitivity to Cr2O72- by fluorescence quenching mechanism. Competitive experiments in presence of other anions, such as F-, Cl-, Br-, I-, N-3(-), SO42-, CH3COO-, ClO4-, NO3-, CO32- and the effect of pH on the effectiveness of the chemosensor 6 have also been explored. Chemosensor 6 displayed good selectivity to Cr2O72- ions over other anion tested as no significant interference was observed. Under optimized conditions, the response of chemosensor 6 was linearly proportional to the concentration of Cr2O72- in a range from (10-100 mu M) with determination coefficient of 0.9911. This method work effectively for the direct detection of Cr2O72- ion in real samples.