Rare Earth Hybrid Research Articles

Hybrid Lanthanide Metal–Organic Compounds with Flavonoids: Magneto-Optical Properties and Biological Activity Profiles

Lanthanides have seen rapid growth in the pharmaceutical and biomedical field, thus necessitating the development of hybrid metal–organic materials capable of exerting defined biological activities. Ternary hybrid lanthanide compounds were synthesized through reaction systems of Ln(III) (Ln = La, Nd, Eu) involving the antioxidant flavonoid chrysin (Chr) and 1,10-phenanhtroline (phen) under solvothermal conditions, thus leading to pure crystalline materials. The so-derived compounds were characterized physicochemically in the solid state through analytical (elemental analysis), spectroscopic (FT-IR, UV-visible, luminescence, ESI-MS, circular dichroism, 151Eu Mössbauer), magnetic susceptibility, and X-ray crystallographic techniques. The analytical and spectroscopic data corroborate the 3D structure of the mononuclear complex assemblies and are in line with theoretical calculations (Bond Valence Sum and Hirshfeld analysis), with their luminescence suggesting quenching on the flavonoid-phen electronic signature. Magnetic susceptibility data suggest potential correlations, which could be envisioned, supporting future functional sensors. At the biological level, the title compounds were investigated for their (a) ability to interact with bovine serum albumin and (b) antibacterial efficacy against Gram(−) (E. coli) and Gram(+) (S. aureus) bacteria, collectively revealing distinctly configured biological profiles and suggesting analogous applications in cellular (patho)physiologies.

Three new organic hybrid lanthanide antimony selenides with photocurrent response and photocatalytic properties

Three new organic hybrid lanthanide antimony selenides [Ln(teta)2][SbSe4] [teta = triethylenetetramine, Ln = Ho (1a), Er (1b) and Tm (1c)] were solvothermally synthesized and structurally characterized. 1a-c are isostructural and their crystal structures consist of discrete [Ln(teta)2]3+ cations and [SbSe4]3− anions, which are interconnected by the NH···Se hydrogen bonds, resulting in the three-dimensional network structures. The absorption edges of 1a-c are in the range of 1.82–1.99 eV, implying the excellent visible-light harvesting ability. Consequently, 1a-c show remarkable photocurrent response and photocatalytic degradation of methylene blue under visible-light irradiation. This work not only presents the rare example of lanthanide antimony selenides as visible-light-driven photo-catalysts, but also offers a reliable way for the preparation of other new lanthanide antimony selenides with photoelectric and photocatalytic properties.

Molecular Engineering Regulation Achieving Out-of-Plane Polarization in Rare-Earth Hybrid Double Perovskites for Ferroelectrics and Circularly Polarized Luminescence.

Out-of-plane polarization is a highly desired property of two-dimensional (2D) ferroelectrics for application in vertical sandwich-type photoferroelectric devices, especially in ultrathin ferroelectronic devices. Nevertheless, despite great advances that have been made in recent years, out-of-plane polarization remains unrealized in the 2D hybrid double perovskite ferroelectric family. Here, from our previous work 2D hybrid double perovskite HQERN ((S3HQ)4EuRb(NO3)8, S3HQ=S-3-hydroxylquinuclidinium), we designed a molecular strategy of F-substitution on organic component to successfully obtain FQERN ((S3FQ)4EuRb(NO3)8, S3FQ=S-3-fluoroquinuclidinium) showing circularly polarized luminescence (CPL) response. Remarkably, compared to the monopolar axis ferroelectric HQERN, FQERN not only shows multiferroicity with the coexistence of multipolar axis ferroelectricity and ferroelasticity but also realizes out-of-plane ferroelectric polarization and a dramatic enhancement of Curie temperature of 94 K. This is mainly due to the introduction of F-substituted organic cations, which leads to a change in orientation and a reduction in crystal lattice void occupancy. Our study demonstrates that F-substitution is an efficient strategy to realize and optimize ferroelectric functional characteristics, giving more possibility of 2D ferroelectric materials for applications in micro-nano optoelectronic devices.

A novel hybrid lanthanide metal-organic frameworks based on porphyrin for rapid detection of iron ions

BackgroundIron ion (Fe3+) is essential for the environment and human health. Detecting Fe3+ in water is crucial, making high-performance detection a key objective. Lanthanide metal-organic frameworks with abundant functional sites have been deemed a promising fluorescence sensor for Fe3+ detection. Currently, most metal-organic framework-based sensors for Fe3+ detection have cumbersome and time-consuming synthesis procedures and long detection times, which greatly limits their practical application. This study aims to construct a hybrid lanthanide metal-organic frameworks-based fluorescence sensor for Fe3+ detection that promises simple and rapid iron ion quantification in water. ResultsA novel hybrid lanthanide metal-organic frameworks (ECTMNs) was synthesized in one step using a solvothermal method with only 4 h. The frameworks comprise two metal ions, cerium and europium, serving as metal centers, and 4,4,4,4-(Porphine-5,10,15,20-tetrayl) tetrakis (TCPP) as an organic ligand. With the addition of Fe3+, the host-guest reaction occurred between Fe3+ and ECTMNs probe, leading to the gradual fluorescence burst of ECTMNs probe. A strong linear correlation between ECTMNs fluorescence intensity and Fe3+ concentration (1–90 μM) makes it a reliable sensor for Fe3+ monitoring with a detection limit of 0.3 μM. Moreover, the method was used to analyze real samples (tap water and river water), showing good recoveries (92–98 %) and low relative standard deviations (3.96–6.11 %), making it a promising option for rapidly detecting Fe3+. Significance and noveltyA rapid synthesis protocol for hybrid lanthanide metal-organic frameworks is proposed in this study. The obtained ECTMNs exhibits good water solubility, high stability, and specificity for Fe3+. Based on ECTMNs, an innovative fluorescence sensor is established for selectively detecting Fe3+ in water, which is a simple operation method with a low detection limit and short sensing time. It provides a novel method for accurately and rapidly detecting Fe3+ in environmental pollution and water safety monitoring.

Exploring the Feasibility of Eu(TTA)3TPPO as Pigment for Fluorescent Paint

We outline the synthesis of rare earth hybrid organic β-diketonate Eu(TTA)3TPPO complex [Eu: Europium, TTA: Thenoyl Trifluoro Acetone, TPPO: Triphenylphosphine oxide] pigment to formulate luminous paints. Epoxy and urea formaldehyde resins were synthesized by catalytic homo polymerization and solution polymerization technique, respectively. The fluorescent pigment was synthesized at ambient temperature by solution technique, maintaining the stoichiometric ratio at pH 7. Nextly, fluorescent paint was developed on glass substrate with epoxy (E) and urea formaldehyde (UF) resins and toluene as solvent with thickness 0.1 mm, respectively. Photoluminescence (PL) spectra and photometric assessment of the complex were carried out to probe its photophysical parameters. The excitation spectra of the synthesized complex depicts a wide-ranging excitation peak at 466 nm with a wide shoulder at 538 nm, while emission spectra discloses an intense peak, recorded at 617 nm which portrays colour in the reddish-orange region of the visible spectrum. The paint compositions were checked for tack-free, hard dry, adhesion, water, salt, alkali and acid spray test to study their resistance against distinct surroundings. The painted panels also portrayed reddish orange emission at a unique wavelength of 617 nm. Amid all the paint compositions, the intensity of the painted panel with urea formaldehyde as a binder was found to be maximum, followed by the painted panel with epoxy as the binder. Photometric evaluation revealed reddish-orange emission from pure pigment as well as painted panels, which portrayed in the visible spectrum. This proposes a way to develop fluorescent paints that find applications in several areas such as flexible displays, glow-in-dark road paints, OLED devices, automotive rare lighting, fluorescent sensors, aircraft cabin and floor lighting, architectural and interior decorations and many more.

Exploring the Feasibility of Eu(TTA)<sub>3</sub>TPPO as Pigment for Fluorescent Paint

We outline the synthesis of rare earth hybrid organic β-diketonate Eu(TTA)3TPPO complex [Eu: Europium, TTA: Thenoyltrifluoroacetone, TPPO: Triphenylphosphine oxide] pigment to formulate luminous paints. Epoxy and urea-formaldehyde resins were synthesized by catalytic homo polymerization and solution polymerization technique, respectively. The fluorescent pigment was synthesized at ambient temperature by solution technique, maintaining the stoichiometric ratio at pH 7. Nextly, fluorescent paint was developed on glass substrate with epoxy (E) and urea-formaldehyde (UF) resins and toluene as solvent with thickness 0.1 mm, respectively. Photoluminescence spectra and photometric assessment of the complex were carried out to probe its photophysical parameters. The excitation spectra of the synthesized complex depict a wide-ranging excitation peak at 466 nm with a wide shoulder at 538 nm, while emission spectra disclosed an intense peak, recorded at 617 nm which portrays color in the reddish-orange region of the visible spectrum. The paint compositions were checked for tack-free, hard dry, adhesion, water, salt, alkali, and acid spray test to study their resistance against distinct surroundings. The painted panels also portrayed reddish-orange emission at a unique wavelength of 617 nm. Amid all the paint compositions, the intensity of the painted panel with UF as a binder was found to be maximum, followed by the painted panel with epoxy as the binder. Photometric evaluation revealed reddish-orange emission from pure pigment as well as painted panels, which are portrayed in the visible spectrum. This proposes a way to develop fluorescent paints that find applications in several areas such as flexible displays, glow-in-dark road paints, OLED devices, automotive rare lighting, fluorescent sensors, aircraft cabin and floor lighting, architectural and interior decorations, and many more. Received: 23 January 2024 | Revised: 1 April 2024 | Accepted: 27 May 2024 Conflicts of Interest The authors declare that they have no conflicts of interest to this work. Data Availability Statement Data are available on request from the corresponding author upon reasonable request. Author Contribution Statement Vyankatesh Rajhans: Formal analysis, Investigation, Data curation, Writing – original draft, Visualization. N. Thejo Kalyani: Conceptualization, Methodology, Validation, Resources, Writing – review & editing, Supervision, Project administration. Akhilesh Ugale: Software, Writing – review & editing. S. J. Dhoble: Supervision, Project administration.

Unravelling the Mechanism of CO2 Activation: Insights Into Metal-Metal Cooperativity and Spin-Orbit Coupling with {3d-4f} Catalysts.

Converting CO2 into useful chemicals using metal catalysts is a significant challenge in chemistry. Among the various catalysts reported, transition metal lanthanide hybrid {3d-4f} complexes stand out for their superior efficiency and site selectivity. However, unlike transition metal catalysts, understanding the origin of this efficiency in lanthanides poses a challenge due to their orbital degeneracy, rendering the application of DFT methods ineffective. In this study, we employed a combination of density functional theory (DFT) and ab initio CASSCF/RASSI-SO calculations to explore the mechanism of CO2 conversion to cyclic carbonate using a 3d-4f heterometallic catalyst for the first time. This work unveils the importance of 3d and 4f metal cooperativity and the role of individual spin-orbit states in dictating the overall efficiency of the catalyst.

Multicolor Fluorescent Inks Based on Lanthanide Hybrid Organogels for Anticounterfeiting and Logic Circuit Design.

With the rapid development of information technology, the encrypted storage of information is becoming increasingly important for human life. The luminescent materials with a color-changed response under physical or chemical stimuli are crucial for information coding and anticounterfeiting. However, traditional fluorescent materials usually face problems such as a lack of tunable fluorescence, insufficient surface-adaptive adhesion, and strict synthesis conditions, hindering their practical applications. Herein, a series of luminescent lanthanide hybrid organogels (Ln-MOGs) were rapidly synthesized using a simple method at room temperature through the coordination between lanthanide ions and 2,6-pyridinedicarboxylic acid and 5-aminoisophthalic acid. And the multicolor fluorescent inks were also prepared based on the Ln-MOG and hyaluronic acid, with the advantages of being easy to write, color-adjustable, and water-responsive discoloration, which has been applied to paper-based anticounterfeiting technology. Inspired by the responsiveness of the fluorescent inks to water, we designed a logic system that can realize single-input logic operations (NOT and PASS1) and double-input logic operations (NAND, AND, OR, NOR, XOR). The encryption of a binary code can be actualized utilizing different luminescent response modes based on the logic circuit system. By adjusting the energy sensitization and luminescence mechanism of lanthanide ions in the gel structure, the information reading and writing ability of the fluorescent inks were verified, which has great potential in the field of multicolor pattern anticounterfeiting and information encryption.

High efficient and ultrahigh thermal stability in a rigid rare-earth hybrid molecular crystal: [(CH3CH2)4N]Tb[CH2(SO3)2

Organic-inorganic hybrid molecular fluorescent materials have attracted much attention due to their application potential in white LEDs and high-definition displays. However, achieving high thermal stability for the fields of lighting/displays remains greatly challenging based on the hybrid molecular materials. Herein, we reported a crystalline state 1D rigid rare-earth hybrid coordinate polymer molecular crystal [(CH3CH2)4N]Tb[CH2(SO3)2] (1) along with high quantum yield (QY) 75.2%. Interestingly, this hybrid molecular crystal remains stable up to 728 K (∼455 °C). Remarkably, it exhibits excellent fluorescence thermal stability at high temperatures (150 °C, >95% and 150–200 °C, >82%) and a high thermal activation energy of 568.7 meV. Besides, the fabricated n-UV chips based white-LED by 1, commercial red Y2O3:Eu3+ and blue BaMgAl10O17:Eu2+ phosphor emits white light with color coordinates (CIE, 0.33, 0.32), high color rendering index (CRI) of 91.2, and correlated color temperature (CCT) 5623 K. These results reveal that this ultrahigh thermal stability hybrid molecular crystal as a green phosphor has great potential applications for displays or WLEDs. Therefore, this study opens a new avenue to develop novel rare-earth phosphors and gives new visions for hybrid molecular fluorescent materials.

Polyarylether-based COFs coordinated by Tb3+ for the fluorescent detection of anthrax-biomarker dipicolinic acid.

In this study, a rare-earth hybrid luminescent material (lanthanide@COF) was constructed for the detection of a biomarker for anthrax (dipicolinic acid, DPA). JCU-505-COOH was prepared by the hydrolysis of the cyano group in JCU-505 via a post-synthetic modification strategy, then the carboxyl groups in JCU-505-COOH coordinated with Tb3+ ions, similar to pincer vising nut. The prepared Tb3+@JCU-505-COOH exhibited a turn-on response toward DPA, which allowed the lanthanide@COF to serve as a fluorescence sensor with excellent selectivity and high sensitivity (binding constant Ka = 3.66 × 103). The fluorescent probe showed satisfactory performance for the determination of DPA in saliva and urine with a detection limit of 0.6 μM. Moreover, we established a facile point-of-care testing (POCT) using the Tb3+@JCU-505-COOH-based fluorescent test paper together with a smartphone for the initial diagnosis of anthrax. As expected, Tb3+@JCU-505-COOH showed great potential for the rapid screening of anthrax due to low cost, simple operation, and wide applicability.

Rare Earth Nitrate Hybrid Double Perovskites [Me4N]2[MLn(NO3)6] (M = Na-Cs; Ln = La-Gd, ex. Pm).

An exploration of the synthetic and structural phase space of rare earth hybrid double perovskites A2B'BX6 (A = organocation, B' = M+, B = M3+, X = molecular bridging anion) that include X = NO3- and B' = alkali metal is reported, complementing earlier studies of the [Me4N]2[KB(NO3)6] (B = Am, Cm, La-Nd, Sm-Lu, Y) (Me4N = (CH3)4N+) compounds. In the present efforts, the synthetic phase space of these systems is explored by varying the identity of the alkali metal ion at the B'-site. Herein, we report three new series of the form [Me4N]2[B'B(NO3)6] (B = La-Nd, Sm-Gd; B' = Na, Rb, Cs). The early members of the Na-series crystallize in the trigonal space group R3̅ from La to Nd where a phase transition occurs in the phase between 273 and 300 K, going from R3̅ to the high-symmetry, cubic space group Fm3̅m. The preceding trigonal members of the Na-series also undergo phase transitions to cubic symmetry at temperatures above 300 K, establishing a decreasing trend in the phase-transition temperature. The remainder of the Na-series, as well as the Rb- and Cs-series, all crystallize in Fm3̅m at 300 K. The temperature-dependent phase behavior of the synthesized phases is studied via variable-temperature spectroscopic methods and high-resolution powder X-ray diffractometry. All phases were characterized via single-crystal and powder X-ray diffraction and Fourier transform infrared (FT-IR) and Raman spectroscopic methods. These results demonstrate the versatility of the perovskite structure type to include rare earth ions, nitrate ions, and a suite of alkali metal ions and serve as a foundation for the design of functional rare earth hybrid double perovskite materials such as those possessing useful multiferroic, optical, and magnetic properties.

Ultraviolet Emission from Cerium‐Based Organic‐Inorganic Hybrid Halides and Their Abnormal Anti‐Thermal Quenching Behavior

AbstractRare earth elements are widely employed and investigated as dopants in luminescent materials because of their ability to modulate hosts’ specific physical and chemical properties. However, stable phosphors crystallized with pure rare earth elements are few and hence their potential for wider utilization is largely limited. Herein, two examples of cerium (Ce)‐based organic–inorganic hybrid halides, (DFPD)4CeX7 (DFPD+ = 4,4‐difluoropiperidinium; X− = Cl− and Br−) and (DFPD)CeCl4·2MeOH are demonstrated. The Cl compositions of both examples are capable of emitting the fascinating ultraviolet (UV) light (350–375 nm), which represents the shortest emission wavelength ever reported in existing metal halide perovskites. Moreover, the resulting crystals are of high quality, which have intrinsic photoluminescence quantum yields of 95%–100%. Besides, in contrast to their all‐inorganic counterparts like Ce3CeBr6, the proposed two forms of Ce3+‐based halides show abnormal anti‐thermal quenching behavior (≈128% of emission intensity at 420 K relative to 80 K), being particularly applicable for practical use in a heated environment. A phosphor‐converted light‐emitting diode fabricated with (DFPD)4CeCl7 demonstrates stable UV emission (840 min) and has a high external quantum efficiency of 1%. This study opens up the way to a possible design of robust UV‐emitting structures based on rare earth hybrid metal halides.

Application of TEMPO‐Oxidized Cellulose Nanofibrils/Lanthanide Hybrid Materials TOCN/Eu(III) as Luminescent Sensor

AbstractThis study prepares lanthanide rare earth ion‐doped optical materials TOCN/Eu(III) based on the simple blending reaction of TEMPO‐oxidized cellulose nanofiber (TOCN) with trivalent lanthanide ions (Eu3+). The carboxyl groups on the surface of TOCN are adopted to generate solid ionic bonds with rare earth ions (Eu3+) so that TOCN/Eu(III) emits solid red light under UV irradiation. TOCN/Eu(III) composites are synthesized and proved to selectively detect Fe3+. This finding suggests that the cellulose‐based lanthanide hybrid material, TOCN/Eu(III), holds promising application potential as a fluorescent probe for the selective detection of Fe3+ ions.

Lanthanide and Ladder-Structured Polysilsesquioxane Composites for Transparent Color Conversion Layers

Ladder-type polysilsesquioxanes (LPSQs) containing phenyl as a high refractive index unit and cyclic epoxy as a curable unit were found to be excellent candidates for a transparent color conversion layer for displays due to being miscible with organic solvents and amenable to transparent film formation. Therefore, the LPSQs were combined with luminescent lanthanide metals, europium Eu(III), and terbium Tb(III), to fabricate transparent films with various emission colors, including red, orange, yellow, and green. The high luminescence and transmittance properties of the LPSQs-lanthanide composite films after thermal curing were attributed to chelating properties of hydroxyl and polyether side chains of LPSQs to lanthanide ions, as well as a light sensitizing effect of phenyl side chains of the LPSQs. Furthermore, Fourier-transform infrared (FT-IR) and X-ray photoelectron spectroscopy and nanoindentation tests indicated that the addition of the nanoparticles to the LPSQs moderately enhanced the epoxy conversion rate and substantially improved the wear resistance, including hardness, adhesion, and insusceptibility to atmospheric corrosion in a saline environment. Thus, the achieved LPGSG-lanthanide hybrid organic-inorganic material could effectively serve as a color conversion layer for displays.

Shape memory luminescent cellulose/chitosan hydrogel for high sensitive detection of formaldehyde

Hybrid hydrogels containing biomacromolecules have been widely used in sensors, fluorescent probes, and other fields due to their high biocompatibility and nontoxicity. In this paper, tough hydrogels with interconnected macro-pores have been fabricated by freeze-induced chemical cross-linking of microfibrillated cellulose (MFC) and organic modified chitosan (CS). In this hydrogel materials, three-dimensional networks were formed by abundant hydrogen bonds and chemical cross-linking. Luminescent lanthanide complexes were covalently bonded to the hydrogel networks through coordination of Eu3+ ions with 2, 3-pyridine dicarboxylic acid modified chitosan. The luminescence of hydrogel materials was further improved by the replacement of coordination water with 2-thiophenyltrifluoroacetone (TTA). The prepared hydrogels showed excellent shape memory properties both under water and in air. The stress of the hybrid hydrogel at 80 % strain can reach 159 kPa, which is much higher than that of the traditional microfibrillated cellulose-based hydrogels. The obtained luminescent hybrid hydrogels exhibited an excellent fluorescence detection effect on formaldehyde. The detection limit for formaldehyde is 45.7 ppb, which is much lower than the WHO standard (80 ppb for indoor air). The novel, facile preparing procedure may extend the potential applications of hybrid lanthanide luminescent hydrogel as fluorescence probes for pollution monitoring, especially for formaldehyde and other organic aldehydes.

Facile solvothermal preparation of an organic hybrid dysprosium selenidoantimonate for an efficient oxygen evolution reaction.

To overcome the issue of the sluggish kinetics in the oxygen evolution reaction (OER), the development of an efficient OER electrocatalyst with high intrinsic activity is very desirable for green hydrogen energy utilization from electrochemical water splitting. Herein, a facile and feasible solvothermal reaction of Sb, Se, DyCl3 and triethylenetetramine (teta) at 170 °C for 7 days achieved a new organic hybrid dysprosium selenidoantimonate [Dy(teta)2][SbSe4] (SbSe-1), which comprises discrete [SbSe4]3- and [Dy(teta)2]3+ ions. SbSe-1 was utilized in combination with acetylene black (AB), Ni nanoparticles and the porous Ni foam (NF) support to fabricate a Ni/SbSe-1@AB/NF electrode as an efficient anodic electrocatalyst, showing excellent OER electrocatalytic performance with a low overpotential of 269 mV at 10 mA cm-2. Although some antimony chalcogenides are used as electrocatalysts for the water splitting, organic hybrid lanthanide chalcogenidoantimonates applied as OER electrocatalysts have not emerged. Therefore, SbSe-1 offers the first example of an organic hybrid lanthanide chalcogenido-antimonate as an OER electrocatalyst.

Tri-channel tubular lanthanide nanocomposites for multimodal anti-counterfeiting

Integrating multiple signals with different excitation wavelength dependence and temperature response properties into a single nanomaterial to construct multimodal anti-counterfeiting materials is still challenging. In this research, an exciting lanthanide hybrid tri-channel tubular anti-counterfeiting nanomaterial was fabricated by fixing NaYF4:Yb3+/Tm3+ up-conversion nanoparticles and Cit-Eu-TC complex on the surface of YHF:Ce/11.4%Tb nanotubes, which can be further used to make anti-counterfeiting fluorescent ink and hydrogel. The hidden three-mode anti-counterfeiting patterns showed bright green, red, and blue-violet fluorescence under 254 nm, 365, and 980 nm excitation, respectively. More importantly, under the co-irradiation of 254 and 365 nm light, the patterns prepared by the anti-counterfeiting ink showed mesmerizing dynamic anti-counterfeiting performance under the stimulation of developer and temperature. With the developer's dosage increase or temperature change, the color of anti-counterfeiting patterns changed obviously. The combination of this dynamic stimulus-responsive anti-counterfeiting feature and the above three-channel static anti-counterfeiting feature might bring about multi-mode static-dynamic anti-counterfeiting performance, significantly improving the difficulty of forgery and was expected to be widely used in the field of confidential information and file anti-counterfeiting.

H/F Substitution Induced Enhancement of Phase Transition Temperature and Quantum Yield in Rare-Earth Hybrid Perovskite

Organic–inorganic hybrid perovskites (OIHPs) with switchable properties are believed to be important as stimuli-responsive materials. Herein, we report two ABX2-type OIHPs: [(CH3)3NCH2R]2[Eu(H2O)]2[CH2(SO3)2]4·2H2O (R = H, 1; F, 2) by using [CH2(SO3)2]2– bridged rare-earth (RE) ions. Meanwhile, these self-assembled host–guest compounds display structural phase transition with a dielectric switch and fluorescent response. Notably, H/F substitution enhanced the intermolecular interactions between the anionic host and the cationic guest. This results in skeleton deformation and changes in the spatial arrangement and symmetry of Eu3+. As a result, the phase transition temperature (Ttr) moved up, and the fluorescence quantum yield (FQY) increased by 4.73%. The molecular assembly strategy proposed in this work will benefit the construction of new multifunctional stimuli-responsive materials.

Killing two birds with one stone: Construction of a rare earth hybrid dual-channel fluorescent biosensor with intelligent broadcasting function and visualized synchronous assessment of multi-objectives

Contamination of pathogenic bacteria and abuse of antibiotics have become important factors restricting the healthy and rapid development of animal husbandry. Simultaneous quantitative detection of pathogenic bacteria and antibiotics is not only the need of animal husbandry development, but also a challenge in the development of sensor analysis technology. In this study, a dual-channel fluorescent biosensor based on tubular halloysite (THT) loaded with carbon dots and lanthanide bimetal organic frameworks was prepared (THT@CDs-MOF), which contained blue emitters (peak emission at 450 nm under 365 nm excitation) and red emitters (peak emission at 616 nm under 254 nm excitation). The obtained dual-channel biosensor can realize quick visual intelligent assessment of 2,6-pyridinedicarboxylic acid (DPA) through energy transfer under 254 nm excitation and tetracycline (TC) through antenna effect and internal filtering effect (IFE) under 365 nm excitation. This biosensor can detect DPA with a concentration of 0–72 μM (LOD was 6.07 nM) and TC with a concentration of 0–19 μM (LOD was 11.31 nM). By fixing the biosensor on agarose, a biosensor with rapid visualization for simultaneous detection of DPA and TC was obtained. Importantly, a color recognition speech broadcasting system based on 51 single-chip microcomputer for the real-time semi-quantitative identification of DPA and TC was also developed, which promoted the application of artificial intelligence in the field of small molecules analysis.

Hybrid lanthanide double-deckers based on calixarene and polyoxometalate units.

Complementarity of calixarene (H2L) and polyoxometalate ligands results in the first organic-inorganic [MIIIL{Mo5O13(OMe)4(NO)}]2- (M = Y, Gd and Dy) hybrid, directing the formation of a distorted square-antiprismatic MO8 ligand field and resulting in slow relaxation of the magnetisation for the Dy derivative.