Highly sensitive and selective fluorescent detection of phosphate in water environment by a functionalized coordination polymer

Phosphate, due to its somatotrophic effect on organisms, can cause severe eutrophication with excessive content in water. Conventional methods for phosphate detection, which are based on complicated instruments, are time-consuming. Here we report a luminescent lanthanide functionalized coordination polymer (Eu@BUC-14) by doping Eu³⁺ cations to BUC-14 nanocrystals. This Eu³⁺ functionalized hybrid (Eu@BUC-14) presents excellent luminescence features of Eu³⁺ ion that originated from efficient energy transfer from the ligand. The detection results show that Eu@BUC-14 is a highly efficient luminescent probe for phosphate detection in aqueous solutions, exhibiting high sensitivity with a low detection limit of 0.88 μM and a short response time of within 5 min. More significantly, Eu@BUC-14 has a high specificity for PO₄³⁻ over fifteen other pollutant anions and eleven metal cations. The sensing mechanism is proposed via an in-depth analysis of the interaction between PO₄³⁻ and Eu³⁺. Simultaneously, it displays high adsorption ability toward PO₄³⁻ (57.9 mg P/g), making it an outstanding multifunctional material. And the adsorption process plays an important role in preconcentration of PO₄³⁻ which can lead to a quick fluorescent response with high quenching efficiency. The practicality of Eu@BUC-14 was also validated by sensing PO₄³⁻ in real environment water samples.