Luminescence of Sm3+ in double perovskite-type Ba2SrWO6 for insect trapping.

The predominant method for pest control has been the use of pesticides, which have been shown to have detrimental effects on soil, freshwater, and crop quality. Therefore, the development of novel and sustainable crop protection strategies has become increasingly imperative. In this study, a novel orange-red emitting Ba2SrWO6: Sm3+ phosphor was synthesized using the high-temperature solid-state reaction. Under ultraviolet excitation, the phosphors showed obvious emission peaks at 575, 614, and 662 nm. The Ba2SrWO6: Sm3+ was used to fabricate a fluorescence film with polydimethylsiloxane (PDMS), and attracted twice as many insects as the blank control group under 365 nm ultraviolet light. This material holds great potential as a fluorescent agent for insect trapping in the pest control fields of tea, cotton, eggplant, rice, potato, grape, and other agricultural industries. Our findings provide an eco-friendly approach to pest management for the increment of food production.

Structural, photoluminescence, and optical characteristics of a Sm3+ -doped lead borate-strontium-tungsten glass system: Evaluation of Judd-Ofelt intensity parameters and radiative properties.

In this study, the melt quenching approach is used to synthesize a lead borate-strontium-based glass system doped with samarium ions. Modifications in the glass network structure arising from the addition of various concentrations of Sm3+ ions were investigated via Fourier transform infrared (FTIR) spectroscopy. FTIR analysis revealed B-O-B bridges, BO3 , and BO4 units are present. UV-vis-NIR spectroscopic measurement was performed to study the optical absorption spectra. Optical constants such as optical bandgap energies, refractive indices, and other related parameters were evaluated. The lifetime fluorescence decay was measured and ranged between 1.04 and 1.88 ns. The photoluminescence spectra in the range 500-750 nm revealed four transitions from the ground state 6 G5/2 to the excited states 6 H5/2 , 6 H7/2 , 6 H9/2 and 6 H11/2 and J-O theory was utilized to study these optical transitions for Sm3+ ions. Calculations of the oscillator strengths and J-O intensity parameters were performed and the obtained J-O parameters followed the sequence Ω4 > Ω6 > Ω2 . The ratio O/R indicated a high lattice asymmetry around the samarium ions. The values of lifetimes and branching ratios for the fabricated samples emphasized their suitability to be used in laser applications. The current glass samples are good candidates for orange and red emission devices.

Exploring the role of neutral ligands in modulating the photoluminescence of samarium complexes with 1,1,1,5,5,5-hexafluoro-2,4-pentanedione.

Four eight-coordinated luminescent samarium complexes of type [Sm(hfpd)3L2] and [Sm(hfpd)3L'] [where hfpd = 1,1,1,5,5,5-Hexafluoro-2,4-pentanedione L = tri-octyl-phosphine oxide (TOPO) and L' = 1,10-phenanthroline (phen), neocuproine (neoc) and bathocuproine (bathoc) were synthesized via a stoichiometrically controlled approach. This allows for precise control over the stoichiometry of the complexes, leading to reproducible properties. This investigation focuses on understanding the impact of secondary ligands on the luminescent properties of these complexes. Infrared (IR) spectra provided information about the molecular structures, whereas 1H and 13C nuclear magnetic resonance (NMR) spectra confirmed these structural details along with the coordination of ligands to trivalent Sm ion. The UV-vis spectra revealed the molar absorption coefficient and absorption bands associated with the hfpd ligand and photoluminescence (PL) spectroscopy demonstrated intense orange-red emission (648 nm relative to 4G5/2 → 6H9/2) from the complexes. The Commission Internationale de l'Éclairage (CIE) triangles indicated that the complexes emitted warm orange red light with color coordinates (x, y) ranging from (0.62, 0.36) to (0.40, 0.27). The investigation of the band gap as well as color parameters confirms the utility of these complexes in displays and LEDs.

Demystification of luminescence properties and the near imperceptible thermal quenching of Sm3+-doped tungstate phosphors.

Ultra-high thermally stable Ca2MgWO6:xSm3+ (x = 0.5, 0.75, 1, 1.25, and 1.5 mol%) double perovskite phosphors were synthesized through solid-state reaction method. Product formation was confirmed by comparing the X-ray diffraction (XRD) patterns of the phosphors with the standard reference file. The structural, morphological, thermal, and optical properties of the prepared phosphor were examined in detail using XRD, Fourier transform infrared spectra, scanning electron microscopy, diffused reflectance spectra, thermogravimetric analysis (TGA), photoluminescence emission, and temperature-dependent PLE (TDPL). It was seen that the phosphor exhibited emission in the reddish region for the near-ultraviolet excitation with moderate Colour Rendering Index values and high colour purity. The optimized phosphor (x = 1.25 mol%) was found to possess a direct optical band gap of 3.31 eV. TGA studies showed the astonishing thermal stability of the optimized phosphor. Additionally, near-zero thermal quenching was seen in TDPL due to elevated phonon-assisted radiative transition. Furthermore, the anti-Stokes and Stokes emission peaks were found to be sensitive toward the temperature change and followed a Boltzmann-type distribution. All these marked properties will make the prepared phosphors a suitable candidate for multifield applications and a fascinating material for further development.

The Investigation of the Effect of La3+, Eu3+, and Sm3+ Ions on Photoluminescence and Piezoelectric Behavior of RE1.90Y0.10Zr2O7 (RE: Eu, Sm and Y: La, Sm, Eu) Pyrochlore-Based Multifunctional Smart Advanced Materials.

A series of compounds with the general formula RE1.90Y0.10Zr2O7 (where RE includes Eu, Sm and Y includes La, Sm, Eu) were synthesized using a solid-state reaction method. These compounds were analyzed through differential thermal analysis (DTA), thermogravimetric analysis (TG), X-ray powder diffraction (XRD), and scanning electron microscopy (SEM). Additionally, their dielectric constant, loss tangent, piezoelectric charge constant, and Curie temperature were measured using an LCR meter, d33 meter, and TG/DTA. X-ray diffraction results indicated that all samples crystallize in a cubic pyrochlore structure. Photoluminescence studies revealed that Eu3+ ions predominantly contribute to the emission, whether as activators or co-activators. Among the phosphors, Eu1.90La0.10Zr2O7 exhibited a significantly longer afterglow compared to Sm1.90Eu0.10Zr2O7 and Eu1.90Sm0.10Zr2O7. Conversely, Sm1.90Eu0.10Zr2O7 demonstrated luminescence intensity that was 20 times greater than that of Eu1.90La0.10Zr2O7 and Eu1.90Sm0.10Zr2O7. Furthermore, all samples with characteristic Eu3+ emissions also exhibited piezoelectric properties. Curie temperature (Tc) of Eu1.90La0.10Zr2O7, Sm1.90Eu0.10Zr2O7, and Eu1.90Sm0.10Zr2O7 are 770°C, 830°C, and 845°C, respectively. Therefore, Sm3+ ion improves piezoelectric properties and Curie temperature when doping into the Eu2Zr2O7 host crystal.

The effect of SiO2 crystallization in enhancing the luminescence of Dy3+-Sm3+ co-doped glass ceramics for cool white light application.

The present work investigates the structural and luminescence behaviour of Dy3+-Sm3+ co-doped glass ceramics obtained through heat treatment of precursor glasses. The growth of SiO2 polycrystalline particles and evolution of these crystallites in the glass domain are witnessed via XRD and FESEM study. The presence of network vibrational bands, hydroxyl groups and the increased quantity of bridging oxygens (BOs) in glass ceramics are analysed through FTIR spectroscopy study. The absorption study (UV-Visible-NIR) showed the possible electronic transitions of Dy3+ and Sm3+ ions. The red shift in the absorption band edges and the lower bandgap values are obtained as a result of improved heat treatment in glass ceramics. Emission studies show the enhanced luminescence intensity of glass ceramics under 350 and 402 nm excitations. Decay measurement of glass ceramics showed the improved lifetimes of Dy3+ and Sm3+ ions to have appeared in microseconds (×10-6 s). The colour characteristics of glass ceramics analysed using CIE colour chromaticity diagram and correlated colour temperature (CCT) values suggest the neutral to cool white light emissions. Therefore, prepared glass ceramics with SiO2 polycrystalline phase are considered to be suitable materials in cool white LEDs applications.

Luminescence properties of Sr2Ga2GeO7:Bi3+ phosphors and temperature sensing characteristics of co-doped Sm3.

As one of the fundamental physical quantities, temperature is extremely important in various fields. In order to study the temperature sensing characteristics of dual-emitting center phosphors, Bi3+-doped and Bi3+/Sm3+-doped Sr2Ga2GeO7 phosphors were synthesized by high-temperature solid-phase method. Under 312 nm excitation, the Sr2Ga2GeO7:Bi3+ phosphor exhibits a blue broadband emission corresponding to the 3P1 → 1S0 transition of Bi3+ ions. By testing the temperature change spectrum of phosphors, it was found that Bi3+ exhibited strong thermal sensitivity. However, due to the fact that single ion doped phosphors are easily affected by other factors when applied to the field of temperature sensing, based on the thermal sensitivity of Bi3+, Sm3+ with low temperature sensitivity was selected as the co-doped ion, and it was found that the two ions had different thermal quenching characteristics when the temperature change spectrum was tested. Using the temperature detection method based on the fluorescence intensity ratio (FIR) of the dual emission centers, it was found that the best absolute sensitivity Sa was 3.125% K-1 and the maximum relative sensitivity Sr was 1.275% K-1 in the range of 303-423 K. These results show that Sr2Ga2GeO7:Bi3+/Sm3+ phosphors have broad application prospects in the field of optical temperature sensing.

Unexpected Formation of 11(9→7)-abeo-Steroid Skeleton in Synthetic Studies toward Batrachotoxin.

Batrachotoxin (1) is a potent cardio- and neurotoxic steroid isolated from certain species of frogs, birds, and beetles. We previously disclosed two synthetic routes to 1. During our synthetic studies toward 1, we explored an alternative strategy for efficiently assembling its 6/6/6/5-membered steroidal skeleton (ABCD-ring). Here we report the application of intermolecular Weix and intramolecular pinacol coupling reactions. While Pd/Ni-promoted Weix coupling linked the AB-ring and D-ring fragments, SmI2-mediated pinacol coupling did not cyclize the C-ring. Instead, we discovered that SmI2 promoted a 1,4-addition of the α-alkoxy radical intermediate to produce the unusual 11(9→7)-abeo-steroid skeleton. Thus, this study demonstrates the convergent assembly of the skeleton of the natural product matsutakone in 11 steps from 2-allyl-3-hydroxycyclopent-2-en-1-one.

PANI/GO and Sm co-modified Ti/PbO2 dimensionally stable anode for highly efficient amoxicillin degradation: Performance assessment, impact parameters and degradation mechanism.

The abuse and uncontrolled discharge of antibiotics present a severe threat to environment and human health, necessitating the development of efficient and sustainable treatment technology. In this work, we employ a facile one-step electrodeposition method to prepare polyaniline/graphite oxide (PANI/GO) and samarium (Sm) co-modified Ti/PbO2 (Ti/PbO2-PANI/GO-Sm) electrode for the degradation of amoxicillin (AMX). Compared with traditional Ti/PbO2 electrode, Ti/PbO2-PANI/GO-Sm electrode exhibits more excellent oxygen evolution potential (2.63 V) and longer service life (56 h). In degradation experiment, under optimized conditions (50 mg L-1 AMX, 20 mA cm-2, pH 3, 0.050 M Na2SO4, 25 °C), Ti/PbO2-PANI/GO-Sm electrode achieves remarkable removal efficiencies of 88.76% for AMX and 79.92% for chemical oxygen demand at 90 min. In addition, trapping experiment confirms that ·OH plays a major role in the degradation process. Based on theoretical calculation and liquid chromatography-mass spectrometer results, the heterocyclic portion of AMX molecule is more susceptible to ·OH attacks. Thus, this novel electrode offers a sustainable and efficient solution to address environmental challenges posed by antibiotic-contaminated wastewater.

Multicomponent Assembly of Bicyclic Aza-peroxides Catalyzed by Samarium Complexes and Their Cytotoxic Activity.

An original strategy toward bridged tetraoxazaspirobicycloalkanes was developed. The synthesis is based on a three-component condensation-cyclization reaction of primary arylamines with 1,1'-peroxybis (1-hydroperoxycycloalkanes) and pentane-1,5-dial catalyzed by Sm(NO3)3·6H2O. The structures and conformations of the products were determined by X-ray diffraction analysis and 1H and 13C NMR spectroscopy. High cytotoxic activity and biological potential toward ferroptosis induction were found for the synthesized bicyclic aza-peroxides.

Samarium-Based Turn-Off Fluorescence Sensor for Sensitive and Selective Detection of Quinolinic Acid in Human Urine and Serum.

Quinolinic acid (QA) is an index for some diseases, whose detection is of importance. This work presents a samarium metal-organic framework (Sm-MOF) containing 5-sulfoisophthalate ligand (SIP3-). The fluorescence of Sm-MOF integrates the emission at 339 nm from the SIP3- ligand and four characteristic 4G5/2 → 4Hj (j = 5/2, 7/2, 9/2, and 11/2) transitions at 559, 596, 642, and 701 nm from Sm(III). Sm-MOF as a turn-off fluorescence sensor to QA exhibits high sensitivity, selectivity, and durability. The fluorescence quenching response to QA shows a linear relationship of I0/I = 0.00496·CQA + 1.12474 in the QA concentration of 0-500 µM and a limit of detection calculated as 4.11 µM. Sm-MOF shows the structural and fluorescent stabilities in five quenching-recovery cycles. The recoveries of close to 100% in human urine and serum indicate high reliability. The paper-based Sm-MOF sensor displays a rough QA quantitative analysis by recognizing red values in the on-site QA detection.

Visible light-active samarium manganite nanostructures for enhanced water-soluble pollutant degradation.

In this study, a green approach was used to synthesize SmMnO3 magnetic nanoparticles via the auto combustion method, where pomegranate juice was utilized as a natural fuel. The concentration of fuel was varied to investigate its effect on the purity and morphology of SmMnO3 nanoparticles. The physiochemical properties of the synthesized nanoparticles, including crystal structures, morphology, optical, and magnetic properties, were investigated using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier-Transform Infrared Spectroscopy (FTIR), Vibrating Sample Magnetometer (VSM), Diffuse Reflectance Spectroscopy (DRS), X-ray fluorescence (XRF) and Brunauer-Emmett-Teller (BET). The band gap of the as-synthesized nanoparticles was determined to be 1.8 eV, indicating their potential as a photocatalyst. The photocatalytic activity of SmMnO3 nanoparticles was evaluated against Methyl violet and Erythrosine, and the mechanism of photocatalyst was determined using EDTA, benzoic acid, and benzoquinone as scavengers. Photocatalytic activity was studied in both UV and visible light, and it was found that the maximum degradation (94%) was related to the degradation of Erythrosine (10 ppm) in the presence of visible light. The stability test of SmMnO3 performed and confirmed the stability of nanoparticles after 5 cycles. The results suggest that SmMnO3 nanoparticles synthesized via the green auto combustion method using pomegranate juice as a natural fuel can serve as a promising photocatalyst for the degradation of organic pollutants in the environment. Further studies can be conducted to investigate their potential in other applications.

Acute toxicity of single and combined rare earth element exposures towards Daphnia similis.

The increasing use of Rare Earth Elements (REE) in emerging technologies, medicine and agriculture has led to chronic aquatic compartment contamination. In this context, this aimed to evaluate the acute toxic effects of lanthanum (La), neodymium (Nd) and samarium (Sm), as both single and binary and ternary mixtures on the survival of the microcrustacean Daphnia similis. A metal solution medium with (MS) and without EDTA and cyanocobalamin (MSq) as chelators was employed as the assay dilution water to assess REE bioavailability effects. In the single exposure experiments, toxicity in the MS medium decreased following the order La > Sm > Nd, while the opposite was noted for the MSq medium, which was also more toxic than the MS medium. The highest MS toxicity was observed for the binary Nd + La (1:1) mixture (EC50 48 h of 11.57 ± 1.22 mg.L-1) and the lowest, in the ternary Sm + La + Nd (2:2:1) mixture (EC50 48 h 41.48 ± 1.40 mg.L-1). The highest toxicity in the MSq medium was observed in the single assays and in the binary Sm + Nd (1:1) mixture (EC50 48 h 10.60 ± 1.57 mg.L-1), and the lowest, in the ternary Sm + La + Nd (1:2:2) mixture (EC50 48 h 36.76 ± 1.54 mg.L-1). Concerning the MS medium, 75 % of interactions were additive, 19 % antagonistic, and 6 % synergistic. In the MSq medium, 56 % of interactions were synergistic and 44 % additive. The higher toxicity observed in the MSq medium indicates that the absence of chelators can increase the concentrations of more toxic free ions, suggesting that the MS medium should be avoided in REE assays. Additive interactions were observed in greater or equivalent amounts in both media and were independent of elemental mixture ratios. These findings improve the understanding of environmental REE effects, contributing to the establishment of future guidelines and ecological risk calculations.

Orange-red luminescence of samarium-doped bismuth-germanium-borate glass for light-emitting devices.

Samarium (Sm3+ )-doped glass has sparked a rising interest in demonstrating a noticeable emission in the range of 400-700, which is advantageous in solid-state lasers in the visible region, colour displays, undersea communication, and optical memory devices. This study reports the fabrication of Sm3+ -doped bismuth-germanium-borate glasses were established using a standard melt-quenching technique and inspection by absorption, steady-state luminescence, and transient studies. The typical peaks of Sm3+ ions were detected in the visible range under 403 nm excitation. A strong emission band was detected at 599 nm that resembles the 4 G5/2 →6 H7/2 transition of Sm3+ ions for BGBiNYSm0.5 glass. Furthermore, a reddish-orange (coral) luminescence at 646 nm that resembles the 4 G5/2 →6 H9/2 transition was also perceived. The stimulated emission cross-section of 4 G5/2 level for BGBiNYSm0.5 glass was 0.39 × 10-22  cm2 . Lifetime of the 4 G5/2 level was enhanced for the BGBiNYSm0.5 glass and decreased with an increase in active ion concentrations. The lifetime quenching of ions at the metastable state was because of energy transfer among Sm3+ ions by cross-relaxation channels. Commission Internationale de l'Éclairage (CIE) coordinates were evaluated from the emission spectra. Moreover, all the findings recommend these glass as light-emitting materials in the coral region at 599 nm for solid-state lighting applications.

Regioselective SmI2-Mediated Radical ipso-Substitution Cyclization for the Construction of Pyrrolophenanthridinone Skeletons: The Synthesis of Amaryllidaceae Alkaloids.

Here, we report a regioselective, samarium(II) diiodide mediated intramolecular radical ipso-substitution cyclization. Through the use of a methoxy group as a leaving group, it was possible to regulate the regioselectivity of the reaction by changing the temperature and additives. We applied the developed reaction to the synthesis of four Amaryllidaceae alkaloids and have shown that the present reaction successfully overcomes regioselectivity issues encountered with other cyclization methods.

Adjustable luminescence copper nanoclusters nanoswitch based on competitive coordination of samarium ions for cascade detection of adenosine triphosphate and acid phosphatase activity.

Benefit from the strong coordination property, lanthanide metal ions have been used as competitive reagents to modulate the fluorescence changes of the system. However, lanthanide metal ions as inducers for aggregation-induced emission enhancement in nanosystems is rare. Herein, we report a "turn on-off-on" fluorescent switch for cascade detection of acid phosphatase (ACP) and adenosine triphosphate (ATP) based on the competitive coordination of samarium ions (Sm3+). Novel copper nanoclusters (CuNCs) with long wavelength emission (614 nm) stabilized by glutathione (GSH) and glycylglycine (Gly-Gly) have been confirmed to have AIE property. With the continuous aggregation of GSH/Gly-Gly CuNCs under the induction of Sm3+, the fluorescence of the system increased to achieve the "turn-on" process. The coordinated behaviour between Sm3+ and GSH/Gly-Gly CuNCs is discussed. Due to the strong metal coordination ability of ATP, the Sm3+ coordinated with the GSH/Gly-Gly CuNCs is competed out, resulting in the fluorescence "turn-off" process of the system. As the substrate of enzymatic hydrolysis of ACP, with the continuous hydrolysis of ATP by ACP, Sm3+ coordinates with GSH/Gly-Gly CuNCs again, which leads to the AIE effect and realize the fluorescence "turn-on" process of the system. This strategy results in ATP linear range of 0.508 ~ 120.0 µM with a detection limit of 0.508 µM (S/N = 3) and ACP linear range of 0.011 ~ 30.0 U·L-1 with a detection limit of 0.011 U·L-1 (S/N = 3). Application to biologic samples was successful.

Phase I evaluation of CycloSam® (Sm-153-DOTMP) bone seeking radiopharmaceutical in dogs with spontaneous appendicular osteosarcoma.

153 Sm-DOTMP (CycloSam® ) is a newly-patented radiopharmaceutical for bone tumor treatment. DOTMP (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetramethylene-phosphonate) is a macrocyclic chelating agent with superior binding properties to 153 Sm when compared with EDTMP (Quadramet™, used for palliative treatment of bone cancer). CycloSam® was administered at 1 mCi/kg (37 MBq/kg) in a prospective pilot study to seven dogs with bone cancer resulting in no myelosuppression. Then, 13 dogs were enrolled in a prospective clinical trial study using traditional 3+3 dose escalation and starting at 1.5 mCi/kg. Baseline evaluation included hematologic and biochemical testing, diagnosis confirmation, thoracic and limb radiographs, technetium-99 m-HDP bone scintigraphy, and 18 F-FDG PET scan (SUVmax). Toxicity (primary endpoint) was assessed through weekly blood counts and adverse events. Dogs received 1.5 mCi/kg (n = 4), 1.75 mCi/kg (n = 6), and 2 mCi/kg (n = 3) of 153 Sm-DOTMP. Dose-limiting neutropenia and thrombocytopenia were seen at 2 mCi/kg. No dose-limiting nonhematologic toxicities occurred. Efficacy (secondary endpoint) was assessed by objective lameness measurement (body-mounted inertial sensors), owner quality-of-life (QoL) questionnaire, and repeat PET scan. Objective lameness measurement improved in four dogs (53%-60% decrease) was equivocal in three dogs, and worsened in four dogs (66%-115% increase); two dogs were not evaluable. Repeat 18 F-FDG PET scan results varied and change in lameness did not consistently correlate with SUVmax changes. QoL score worsened (n = 5) or was improved/stable (n = 7). Carboplatin chemotherapy (300 mg/m2 IV every 3 weeks ×4) started 4 weeks after 153 Sm-DOTMP injection. No dog died of chemotherapy-related complications. All dogs completed study monitoring. The recommended dose for CycloSam® in dogs is 1.75 mCi/kg, which resulted in some pain control with minimal toxicity and was safely combined with chemotherapy.

Diastereoselective Radical 1,4-Ester Migration: Radical Cyclizations of Acyclic Esters with SmI2.

Reductive cyclizations of carbonyl compounds, mediated by samarium(II) diiodide (SmI2, Kagan's reagent), represent an invaluable platform to generate molecular complexity in a stereocontrolled manner. In addition to classical ketone and aldehyde substrates, recent advances in radical chemistry allow the cyclization of lactone and lactam-type substrates using SmI2. In contrast, acyclic esters are considered to be unreactive to SmI2 and their participation in reductive cyclizations is unprecedented. Here, we report a diastereoselective radical 1,4-ester migration process, mediated by SmI2, that delivers stereodefined alkene hydrocarboxylation products via radical cyclization of acyclic ester groups in α-carbomethoxy δ-lactones. Isotopic labeling experiments and computational studies have been used to probe the mechanism of the migration. We propose that a switch in conformation redirects single electron transfer from SmI2 to the acyclic ester group, rather than the "more reactive" lactone carbonyl. Our study paves the way for the use of elusive ketyl radicals, derived from acyclic esters, in SmI2-mediated reductive cyclizations.

Morphologically Flex Sm-MOF Based Electrochemical Immunosensor for Ultrasensitive Detection of a Colon Cancer Biomarker.

Despite having the potential to synthesize stable metal-organic frameworks (MOFs), rare earth metal-based MOFs have not been exploited extensively. Owing to the high coordination numbers, the MOFs can generate a suitable coordination environment for various applications. Herein, samarium (Sm)-based MOFs were synthesized with three different organic linkers, namely, trimesic acid (TMA), meso-tetra(4-carboxyphenyl)porphine (TCPP), and 1,3,6,8-tetra(4-carboxylphenyl) pyrene(TBPy) by the solvothermal approach. The morphologies of Sm-TMA MOF, Sm-TCPP MOF, Sm-TBPy MOF were rod-shaped, cubic consisting of stacked 2D layers, and spherical made of small cubic structures, respectively. After the electrochemical properties of the synthesized MOFs were investigated, the MOFs were used to fabricate immunosensors for detection of carcinoembryonic antigen using a label-free signaling strategy. The immunosensors exhibited a wide linear detection range and a lower detection limit. The exhibited reproducibility and selectivity of the immunosensors were within the tolerable limits. The established label-free immunosensor has been successfully applied for detection of carcinoembryonic antigen in human serum samples, demonstrating that the rare earth metal-based MOFs are promising for construction of biosensors for medical diagnosis.

A new method for screening acute/chronic lymphocytic leukemia: dual-label time-resolved fluorescence immunoassay.

BACKGROUND: Lymphocytic leukemia (LL) is a primary malignant tumor of hematopoietic tissue, which seriously affects the health of children and the elderly. The study aims to establish a new detection method for screening acute/chronic LL using time-resolved fluorescence immunoassay (TRFIA) via quantitative detection of S100 calcium binding protein A8 (S100A8) and leucine-rich alpha-2-glycoprotein 1 (LRG1) in serum. METHODS: Here a sandwich TRFIA was optimized and established: Anti-S100A8/LRG1 caputre antibodies immobilized on 96-well plates captured S100A8/LRG1, and then banded together with the anti-S100A8/LRG1 detection antibodies labeled with Europium(III) (Eu3+)/samarium(III) (Sm3+) chelates. Finally time resolved fluorometry measured the fluorescence intensity. RESULTS: The sensitivity of S100A8 was 1.15 ng/mL(LogY = 3.4027 + 0.4091 × LogX, R2 = 0.9828, P < 0.001, dynamic range: 2.1-10,000 ng/mL), and 3.2 ng/mL for LRG1 (LogY = 3.3009 + 0.4082 × LogX, R2 = 0.9748, P < 0.001, dynamic range: 4.0-10,000 ng/mL). The intra-assay and inter-assay CVs were low, ranging from 5.75% to 8.23% for S100A8 and 5.30% to 9.45% for LRG1 with high specificity and affinity in serum samples. Bland-Altman plots indicated TRFIA and ELISA kits have good agreement in clinical serum samples. Additionally, the cutoff values for S100A8 and LRG1 were 1849.18 ng/mL and 588.08 ng/mL, respectively. CONCLUSION: The present TRFIA method could be used for the quantitative detection of S100A8 and LRG1 in serum, and it has high sensitivity, accuracy and specificity. Clinically, this TRFIA method could be suitable for screening of LL via the quantitative detection of S100A8 and LRG1.