Hydrothermal Preparation of Five Rare-Earth (Re = Dy, Gd, Ho, Pr, and Sm) Luminescent Cluster-Based Coordination Materials: The First MOFs-based Ratiometric Fluorescent Sensor for Lysine and Bifunctional Sensing Platform for Insulin and Al³⁺

Abstract

Through the powerful hydrothermal method, five rare-earth (Re = Dy, Gd, Ho, Pr, and Sm) three-dimensional (3D) cluster-based metal–organic frameworks (MOFs) have been synthesized, namely, [Dy­(L)­(H2O)­(DMF)] n (1), {[Gd­(L)­(H2O)­(DMF)]·DMF} n (2), {[Ho­(L)­(H2O)­(DMF)]·0.5DMF} n (3), {[Pr­(L)­(H2O)­(DMF)]·0.5DMF} n (4), and {[Sm­(L)­(H2O)1.55(DMF)0.45]·DMF} n (5; H3L = terphenyl-3,4″,5-tricarboxylic acid), which have been determined by single crystal X-ray analyses and PXRD characterization. Structural analyses reveal that, in 1–5, these L3– ligands are linked by five different rare-earth centers, forming the iso-structural nanoporous frameworks. PXRD patterns of bulky samples 1–5 also are consistent with theoretical PXRD patterns confirming their purity. Solid state photoluminesce of free H3L and 1–5 at room temperature also has been investigated indicating strong ligand-based emissions. Besides these, fluorescent dye Rhodamine B (RhB) can be introduced into MOF1 forming the composite material RhB@MOF1 with a high quantum yield of 35%. It is noted that, through deliberately tuning the morphologies of nanoparticle MOF1 under different ultrasonic conditions, RhB@MOF1 can be utilized as the first ratiometric fluorescent sensor to effectively discriminate l- and d-lysine from other amino acid molecules with high K sv values and low LOD values. On the other hand, 2 was for the first time to be utilized as an excellent bifunctional MOFs-based sensing platform to detect insulin and Al3+ with a low detection limit in the human serum solution.

Cu(ii)/Ni(ii)–organic frameworks constructed from the homometallic clusters by 5-(2-carboxyphenoxy)isophthalic acid and N-ligand: synthesis, structures and visible light-driven photocatalytic properties

“…23,24 Recently, MOFs have been demonstrated with a good photocatalytic activity for the degradation of organic dyes such as methyl orange, methylene blue and rhodamine B (RhB) under visible light irradiation. 15,19,[25][26][27][28][29] Due to the high importance of environment protection, how to effectively remove organic pollutants has become a hot social issue, leading to high demands for high-efficiency photocatalysts.…”

Towards Point-of-Care Insulin Detection

“…143 Recently, alternative approaches have been reported using optical methods for the detection of insulin. 162,163 Wang et al report a ratiometric fluorescent sensor using metal−organic frameworks for detecting insulin between 0 and 1.8 μM. 162 Whereas Strano and co-workers use corona-phase molecular recognition to detect insulin in phosphate buffer saline or serum.…”

Highly Enhanced OER Performance by Er-Doped Fe-MOF Nanoarray at Large Current Densities

“…Ma et al proved that Cu-doped Ni 3 S 2 /Co 3 S 4 could not only increased the specific surface area but also alter the electron density of Ni/Co sites [17]. For the past few years, rare-earth elements have received more and more attention on account of the 4f orbitals partial filling [18,19]. Importantly, the doping of rare-earth elements can effectively regulate the electronic and geometric structures of electrocatalysts, thus improving their electrical conductivity and internal catalytic activity.…”