Dual-ligand two-dimensional Europium-organic gels nanosheets for ratiometric fluorescence detecting anthrax spore biomarker

A ratiometric fluorescent probe based on a dual-ligand lanthanide metal–organic framework (MOF) for sensitive detection of aluminium and fluoride ions in river and tap water

“…42,43 The singlet-state (1ππ*) level is 39 841 cm −1 for H 2 TDA 27 and 21 786 cm −1 for BDC-NH 2 . 44 The triplet-state energy (3ππ*) levels of H 2 TDA and BDC-NH 2 are 29 069 cm −1 and 17 214 cm −1 . The Δ E values of H 2 TDA and BDC-NH 2 between S1 and T1 are 18 055 cm −1 and 11 855 cm −1 , respectively.…”

Dual-ligand-functionalized dodeca-nuclear lanthanide–tungsten-cluster incorporated selenotungstates and fluorescence detection of dipicolinic acid (an anthrax biomarker)

“…Considering the strong coordination affinity of DPA towards Eu 3+ ions owing to its unique coordination sites with three active chelating sites (two carboxyl and one pyridyl groups), we speculate that the FL enhancement mechanism might be attributed to the replacement of coordinate H 2 O ligands around Eu 3+ ions in 4 by DPA, which can effectively inhibit the FL quenching triggered by the O–H oscillators of coordinate H 2 O molecules. 56–58 To verify this hypothesis, the number ( q ) of coordinate H 2 O ligands on the Eu 3+ ions in 4 was determined by measuring the decay lifetimes in H 2 O and D 2 O with and without DPA (Fig. 7) according to the equation q = 1.1 × [ τ H 2 O −1 − τ D 2 O −1 − 0.31], where τ H 2 O and τ D 2 O are the lifetimes in H 2 O and D 2 O environments, respectively, and q was found to be 5.4 in the absence of DPA ( τ H 2 O = 0.174 ms, τ D 2 O = 1.927 ms), indicating that about five H 2 O ligands coordinate with the Eu 3+ centers (Table 1 and Fig.…”

Smart intercalation and coordination strategy to construct stable ratiometric fluorescence nanoprobes for the detection of anthrax biomarker

“…In recent years, fluorescence-based nanosensors, especially in biological systems, [16][17][18] have attracted widespread attention for the detection of DPA due to their simple operation with high sensitivities and rapid responses. [19][20][21] More importantly, ratiometric fluorescence methods not only improve the sensitivity and accuracy of the assay but also eliminate the interference of environmental factors. 21,22 Therefore, it is a hot research topic to find a suitable lightresponsive reference with a stable luminous mode in guest materials.…”

“…In recent years, fluorescence-based nanosensors, especially in biological systems, 16–18 have attracted widespread attention for the detection of DPA due to their simple operation with high sensitivities and rapid responses. 19–21…”