A highly sensitive and reversible chemosensor for Hg 2+ detection based on porphyrin‐thymine conjugates

In this study, we demonstrated a highly sensitive, selective, and reversible chemosensor for Hg 2+ determination. This chemosensor was synthesized by direct condensation of thymin‐1‐ylacetic acid with zinc tetraaminoporphyrin, which has a porphyrin core as the fluorophore and four thymine (T) moieties as the specific interaction sites for Hg 2+ . The probe (4T‐ZnP) exhibited split Soret bands with a small peak at 408 nm and a strong band at 429 nm in a dimethylformamide/H 2 O (7/3, v/v) mixed solvent as well as a strong emission band at 614 nm. Upon the addition of Hg 2+ , the probe displayed strong fluorescence quenching due to the formation of T‐Hg 2+ ‐T complexes. With the aid of the fluorescence spectrometer, the chemosensor in the dimethylformamide/H 2 O (7/3, v/v) mixed solvent (0.3 μM) exhibited a detection limit of 6.7 nM. Interferences from other common cations, such as Co 2+ , K + , Sn 2+ , Zn 2+ , Cu 2+ , Ni 2+ , Mn 2+ , Na + , Ca 2+ , Mg 2+ , Pb 2+ , and Cd 2+ , associated with Hg 2+ analysis were effectively inhibited. Copyright © 2015 John Wiley & Sons, Ltd.