Fe3+ Selective Pyrimidine Based Chromogenic and Fluorogenic Chemosensor

Abstract

By using UV-Visible and fluorescence measurements, a new chemosensor N-(pyrimidin-2-yl) thiophene-2-carboxamide (PTC) was introduced for the discriminating and responsive detection of Fe3+ in aqueous methanolic medium. Since the PTC-Fe3+ complexation occurred in 1:1 binding stoichiometry, the receptor PTC preferentially revealed a charge transfer band between 310 to 475 nm in the UV-Vis technique, with the absorption peak at 351 nm. Furthermore, the fluorescence technique, which dampened PTC's fluorescence emission band at 325 nm, showed similar selectivity. The Stern-Volmer graphic shows that fluorescence quenching occurs in a static manner. The series of examined metal ions (Na+, K+, Li+, Cs+, Fe2+, Ni2+, Sr2+, Cu2+, Cd2+, Pb2+, Co2+, Hg2+, Ba2+, Mg2+, Mn2+, Ca2+, Zn2+, Cr3+, Ag+ and Al3+) failed to perturb the UV-Vis and fluorescence of PTC. With PTC, the concentration of Fe3+ can be detected down to 2.03 and 1.24 µM by UV-Vis and fluorescence methods, respectively. HIGHLIGHTS An easy-to-synthesize pyrimidine-based receptor PTC was developed for the detection of Fe3+ PTC showed Fe3+selective turn-off fluorescence and a new charge transfer absorption band at 351 nm LOD of PTC is 2.03 and 1.24 µM, respectively by UV-Vis and fluorescence methods Fluorescence quenching is static in nature GRAPHICAL ABSTRACT

A coumarin-based fluorescent chemosensor as a Sn indicator and a fluorescent cellular imaging agent

“…While some reports determined metal ions down to nanomolar concentration, our LOD value is in the micromolar concentration range, similar to ref. 40–43. Besides, the fluorescence signal of our probe is stable under physiological conditions and it can penetrate into the living cells.…”