A Dy(III) Coordination Polymer Material as a Dual-Functional Fluorescent Sensor for the Selective Detection of Inorganic Pollutants.

A Dy(III) coordination polymer (CP), [Dy(spasds)(HO)] () (NaHspasds = 5-(4-sulfophenylazo)salicylic disodium salt), has been synthesized using a hydrothermal method and characterized. features a 2D layered structure, where the spasda anions act as pentadentate ligands, adopting carboxylate, sulfonate and phenolate groups to bridge with four Dy centers in -: , -: , and monodentate coordination modes, respectively. It possesses a unique (4,4)-connected net with a Schläfli symbol of {4·6}{4}. The luminescence study revealed that exhibited a broad fluorescent emission band at 392 nm. Moreover, the visual blue color has been confirmed by the CIE plot. can serve as a dual-functional luminescent sensor toward Fe and MnO through the luminescence quenching effect, with limits of detection (LODs) of 9.30 × 10 and 1.19 × 10 M, respectively. The LODs are relatively low in comparison with those of the reported CP-based sensors for Fe and MnO. In addition, also has high selectivity and remarkable anti-interference ability, as well as good recyclability for at least five cycles. Furthermore, the potential application of the sensor for the detection of Fe and MnO was studied through simulated wastewater samples with different concentrations. The possible sensing mechanisms were investigated using Ultraviolet-Visible (UV-Vis) absorption spectroscopy and density functional theory (DFT) calculations. The results revealed that the luminescence turn-off effects toward Fe and MnO were caused by competitive absorption and photoinduced electron transfer (PET), and competitive absorption and inner filter effect (IFE), respectively.