A highly sensitive and reversible chemosensor for Hg2+ detection based on porphyrin‐thymine conjugates

In this study, we demonstrated a highly sensitive, selective, and reversible chemosensor for Hg2+ 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 Hg2+. 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/H2O (7/3, v/v) mixed solvent as well as a strong emission band at 614 nm. Upon the addition of Hg2+, the probe displayed strong fluorescence quenching due to the formation of T‐Hg2+‐T complexes. With the aid of the fluorescence spectrometer, the chemosensor in the dimethylformamide/H2O (7/3, v/v) mixed solvent (0.3 μM) exhibited a detection limit of 6.7 nM. Interferences from other common cations, such as Co2+, K+, Sn2+, Zn2+, Cu2+, Ni2+, Mn2+, Na+, Ca2+, Mg2+, Pb2+, and Cd2+, associated with Hg2+ analysis were effectively inhibited. Copyright © 2015 John Wiley & Sons, Ltd. A highly sensitive, selective, and reversible chemosensor based on porphyrin‐thymine conjugates for Hg2+ determination was presented. Upon the addition of Hg2+, the chemosensor displayed strong fluorescence quenching due to the formation of thymine‐Hg2+‐thymine complex. The chemosensor in a dimethylformamide/H2O (7/3, v/v) mixed solvent (0.3 μM) exhibited a detection limit of 6.7 nM.