A new and efficient pyridine-2,6-dicarboxamide-based fluorescent and colorimetric chemosensor for sensitive and selective recognition of Pb2+ and Cu2+

A new fluorene-bearing pyridine-2,6-dicarboxamide (3) as an effectint fluorescent and colorimetric cation sensor was successfully synthesized and well-characterized using FT-IR, NMR, ESI+-MS and elemental analysis. The metal ion binding ability of the chemosensor 3 in the presence of different metal ions was investigated using UV-vis, fluorescence experiments and results exhibited a desirable selectivity and significant sensitivity of the chemosensor 3 for the detection of Cu2+ and Pb2+ ions. The association constant (K-a) of 3-Cu2+ and 3-Pb2+ complexes were determined to be 8.89 x 10(3) M-1 and 5.65 x 10(8) M-2, respectively. The obtained limit of detection (LOD) values (1.49 x 10(-6) M for Cu2+ and 2.31 x 10(-6) M for Pb2+) clearly revealed the considerable sensitivity of the chemosensor 3.

Automated summary

The newly synthesized fluorene/pyridine-2,6-dicarboxamide sensor showed desirable selectivity and significant sensitivity for detecting Cu2+ and Pb2+ ions, with promising application prospects.