Colorimetric detection of Fe2+ and Cr2O72- in environmental water samples based on dual-emitting RhB-embedded Zr-MOFs.

Three dye-loaded tunable dual-emission colorimetric fluorescent probes RhB@UiO-66-Ph (R@U-P) were prepared by in-situ encapsulation method under solvothermal conditions. The resonance energy transfer between UiO-66-Ph and RhB made the dual emission of R@U-P easily tunable with the embedded dye content changing. The R@U-P composites achieved emission from purple light to red light, and served as probes to realize comparative detection of Fe3+, Fe2+ and Cr2O72- in water through colorimetric or quenching detection mode. Mechanism study indicates that the resonance energy transfer or electron transfer interactions between R@U-P composites and inorganic ions resulted in the relative changes of the two emission peaks and realized the selective detection of analytes. The preparation and application of R@U-P probes provide a promising strategy for the in-situ encapsulation dye to obtain two dual-emission composites for the comparative detection of Fe3+, Fe2+ and Cr2O72- in water samples.

Hydrophobic Porphyrin Titanium-Based MOFs for Visible-Light-Driven CO2 Reduction to Formate.

Three hydrophobic porphyrin titanium-based metal-organic frameworks (MOFs) (HPA/DGIST-1, DPA/DGIST-1, and OPA/DGIST-1) were synthesized through a postsynthetic coordination reaction by using alkylphosphonic acid of different lengths (HPA, hexylphosphonic acid; DPA, dodecylphosphonic acid; OPA, octadecylphosphonic acid). Compared with the hydrophilic DGIST-1, modified DGIST-1 exhibits excellent hydrophobicity and presents good stability in humid atmospheres. Due to the introduction of porphyrin ligands, HPA/DGIST-1, DPA/DGIST-1, and OPA/DGIST-1 showed good visible-light absorption (380-700 nm) and sensitive photogenerated charge responses. When acted as catalysts, these hydrophobic Ti-MOFs can selectively reduce CO2 to HCOO- under visible-light irradiation with average reaction rates of 150.9, 178.5, and 228.3 µmol·h-1·g-1, where these values are 1.3-2.0 times higher than the system mediated by the initial porphyrin Ti-MOF catalyst. 13C NMR spectroscopy demonstrates that the catalytic product HCOO- anion originates from the reactant CO2. The photocatalytic experiments, electron paramagnetic resonance, and photoluminescence spectra tests showed that porphyrin ligands and Ti-O units can act as catalytic activity centers to realize the conversion of CO2 to HCOO-. This work demonstrated that the combination of porphyrin titanium-based MOF and alkyl hydrophobic groups is an effective way to enhance the stability of titanium-based MOFs and maintain their high photocatalytic performance.

Identification and investigation of protein-related molecules in patients with hyperlipidemia using label-free combined with bioinformatics analysis.

This study aimed to identify proteins associated with high-fat diet patients and investigate their relationship with this dietary pattern. Five hyperlipidemia female patients and five normal individuals were included as the experiment and control groups, respectively. Blood samples were collected from both groups, and bioinformatics tools were employed for gene ontology annotation, KEGG pathway annotation, GO enrichment analysis, pathway enrichment analysis, and protein clustering to pinpoint genes, proteins, and pathways relevant to high-fat diet patients. Mass spectrometry analysis was subsequently used to confirm these proteins. The results indicated that bioinformatics analysis identified several proteins (P09871, P01019, P48740, P02654, P02649) potentially involved in the high-fat diet process by regulating downstream pathways. Label-free analysis revealed 3915 peptides in both groups, with 16 protein expression levels up-regulated in the experiment group, 13 of which showed significant differences. In contrast, 12 protein expression levels were down-regulated in the experiment group, with two showing significant differences. Notably, the proteins highlighted by bioinformatics analysis aligned with those identified through mass spectrometry. In conclusion, label-free analysis combined with bioinformatics can effectively identify proteins linked to high-fat diet patients. This research provides a fresh perspective on addressing high-fat diet-related issues using this approach.

Aluminum-Porphyrin Metal-Organic Frameworks for Visible-Light Photocatalytic and Sonophotocatalytic Cr(VI) Reduction.

In this study, four isostructural aluminum-based porphyrin metal-organic frameworks [Al-TCPP(M), M = H2 and Zn] with different morphologies and sizes were synthesized by the hydrothermal method. By adjusting the hydrothermal reaction time and the types of porphyrin ligands, Al-TCPP(M) MOFs exhibited diverse morphologies including tetragonal, rectangular, and carambola-like phase. In view of the introduction of porphyrin ligands and the strong coordination effect of Al-O units, Al-TCPP(M) MOFs exhibited good chemical stability, broad visible light harvesting capability, and fast photogenerated charge response. Four Al-TCPP(M) MOFs exhibited excellent photocatalytic activities for Cr(VI) in aqueous solution. Notably, the regulation to the nanoscale carambola-like morphology of Al-TCPP MOFs and metallization of the porphyrin ligand promoted the Cr(VI) photoreduction reaction where the catalytic activity of metallic carambola-like Al-TCPP increased 1.7 times compared to that of nonmetallic tetragonal MOFs. With the assistance of sonophotocatalysis, the Cr(VI) average reduction rates reached 0.658, 0.542, 0.785, and 0.629 mg·L-1·min-1 for Al-TCPP(H2)-24h, Al-TCPP(H2)-72h, Al-TCPP(Zn)-24h, and Al-TCPP(Zn)-72h, which are 1.2-1.4 times higher than that of photocatalysis. UV-vis absorption spectroscopy, electronic spin resonance, and fluorescence spectroscopy experiments demonstrated that the synergistic effect of photochemistry and sonochemistry promoted the transfer of photogenerated electrons from Al-TCPP(M) to Cr(VI), thus enhancing the catalytic activity. The combination of the sonophotocatalytic technology with aluminum-porphyrin MOFs may become an effective strategy to improve MOF-based photocatalytic systems.

Two anthracene-based zirconium metal-organic frameworks with fcu and hcp topologies as versatile fluorescent sensors for detection of inorganic ions and nitroaromatics.

Two anthracene-based zirconium metal-organic frameworks (UiO-68-AN-fcu and UiO-68-AN-hcp) with blue emission were synthesized by the solvothermal reaction of ZrCl4 with anthracene-based ligand 4,4'-(9,10-anthracenediyl)dibenzoic acid. The two MOFs inherited the luminescence properties of anthracene-based ligand and exhibited different topologies due to the change of connection mode of Zr-O clusters. The two stable anthracene-based zirconium MOFs served as luminescent sensors for selectively detecting 2-nitrophenol, Fe3+ and Cr2O72-. UiO-68-AN-hcp with flower morphology exhibited stronger quenching effect for 2-nitrophenol, Fe3+ and Cr2O72- by comparing to UiO-68-AN-fcu. Adsorption tests, fluorescence lifetime and spectroscopy studies demonstrated that the fluorescence responses of MOFs for analytes can be primarily attributed to the dynamic quenching mechanism involving energy and electron transfer. These results revealed that the combination of luminescent anthracene-based ligand and Zr-O clusters is a feasible strategy to construst MOFs-based fluorescent sensors.

Hyperglycemia-induced endothelial exosomes trigger trophoblast dysregulation and abnormal placentation through PUM2-mediated repression of SOX2.

BACKGROUND: Hyperglycemia is closely related to adverse pregnancy outcomes including pre-eclampsia (PE), a life-threatening complication with a substantial morbidity and mortality. However, the pathogenesis of abnormal placentation in gestational diabetes mellitus (GDM)-associated PE remains elusive. METHOD: Here we isolated exosomes from the human umbilical vein endothelial cells (HUVECs) treated with normal level of glucose (NG) and high levels of glucose (HG). The exosomes were added to HTR-8a/SVneo cells, a trophoblast cell line. High-throughput RNA-sequencing was performed to analyzed the changed RNAs in the exosomes and exosome-treated HTR-8a/SVneo cells. HTR-8a/SVneo cell phenotypes were evaluated from the aspects of cell proliferation, cell invasion and DNA damage. RESULTS: After treatment with HG, the changed RNAs in exosomes was enriched in RNA stabilization and oxidative stress. The altered RNAs in the HTR-8a/SVneo cells treated with exosomes from HG-induced HUVECs were enriched in pathways related to cell adhesion, migration, DNA damage response and angiogenesis. The HG-induced exosomes impaired the proliferation and invasion of HTR-8a cells and caused the DNA damage. HG up-regulated PUM2 in the exosomes and exosome-treated HTR-8a/SVneo cells. PUM2 interacted with SOX2 mRNA, resulting in the mRNA degradation. Overexpression of SOX2 prevented the damage to HTR-8a/SVneo cells caused by the exosomes from HG-induced HUVECs. CONCLUSIONS: We demonstrate that high glucose-induced endothelial exosomes mediate abnormal phenotypes of trophoblasts through PUM2-mediated repression of SOX2. Our results reveal a novel regulatory mechanism of hyperglycemia in development of abnormal placentation and provide potential targets for preventing adverse pregnancy outcomes.

Titanium-Porphyrin Metal-Organic Frameworks as Visible-Light-Driven Catalysts for Highly Efficient Sonophotocatalytic Reduction of Cr(VI).

In this work, we synthesized and characterized four titanium-porphyrin metal-organic frameworks (MOFs) [DGIST-1(M), M = Co(II), Fe(III), Zn(II), and H2] and used them as visible-light-driven catalysts for sonophotocatalytic Cr(VI) reduction. DGIST-1(M) exhibited open-framework, broad light absorption stemmed from ligand and sensitive photocurrent responses owing to the integration of one-dimensional Ti-oxo chains and 4-connected conjugated TCPP ligand (TCPP = tetrakis(4-carboxyphenyl)-porphyrin). DGIST-1(M) presented efficient reduction of Cr(VI) to Cr(III) in aqueous solution when used as sonophotocatalytic catalysts. The average reduction rates upon Cr(VI) were 0.920, 0.476, 0.377, and 0.194 mg·L-1·min-1 for DGIST-1(H2), DGIST-1(Zn), DGIST-1(Co), and DGIST-1(Fe), which are 1.15-2.45 times higher than those in photocatalysis. Sonophotocatalytic experiments and electron paramagnetic resonance measurement proved that Ti-oxo chain units and porphyrin ligand in the structures of DGIST-1(M) existed as catalytic active centers for sonophotocatalytic reduction of Cr(VI). Photoluminescence and UV absorption spectra revealed that the unity of photocatalysis and sonochemistry strengthened the migration of photogenerated electrons from DGIST-1(M) to Cr(VI), which improved the activities of catalysts. This study suggested that the association of titanium-porphyrin MOFs and sonophotocatalytic technology is an impactful program for enhancing MOF-based photocatalytic systems.

One-Pot Dual Catalysis of a Photoactive Coordination Polymer and Palladium Acetate for the Highly Efficient Cross-Coupling Reaction via Interfacial Electron Transfer.

We report herein an exploration of the straightforward one-pot dual-catalysis strategy, i.e., direct combination of a photoactive coordination polymer (CP) with another metal catalyst, for carrying out the desirable photoinduced organic transformation. The strategy overcomes the necessity of the presynthesis of the metal/CP composite that has been demonstrated to be invalid in our case. A new two-dimensional CP showing the desirable properties of wide-range visible-light absorption and efficient photoinduced charge generation was synthesized via a solvothermal reaction. The synthesized CP was successfully applied to the photocatalytic C-C cross-coupling reaction via the one-pot dual-catalysis method, in combination with the simple and ligand-free palladium salt of Pd(OAc)2 as a metal catalyst. The reaction features a short reaction time, mild reaction conditions, good recyclability, and a high yield of Heck products from a broad variety of substrates. A comparative experiment showed the presynthesized Pd/CP composite was invalid for the reaction, demonstrating the significance of the one-pot dual-catalysis strategy. Mechanistic studies suggest the one-pot reaction depends on the synergy between the photocatalysis of a synthesized CP to generate reactive aryl radicals and Pd catalysis to generate target products, in which the interfacial electron transfer has been demonstrated to be vital for producing the transient and catalytically active Pd(0) species near the surface of the CP. The study shows the direct combination of a CP photocatalyst and a metal catalyst is a highly feasible method for the photochemical reaction and enhances the prospects of application of photoactive CPs.

Visible-Light-Driven Sonophotocatalysis for the Rapid Reduction of Aqueous Cr(VI) Based on Zirconium-Porphyrin Metal-Organic Frameworks with csq Topology.

Photochemical treatment of highly toxic Cr(VI) is a desirable and ecofriendly method to protect the environment and human beings. In this study, a MOF-based sonophotocatalytic system is established, in which visible-light-driven sonophotocatalytic reduction of toxic Cr(VI) to Cr(III) in water is investigated using zirconium-porphyrin metal-organic frameworks (MOFs) structured as PCN-222(M) [M = H2, Zn(II), Fe(III), Co(II)]. In the view of the synergistic effect of sonochemistry and photocatalysis, PCN-222(M) exhibited enhanced activities for Cr(VI) reduction compared with the photocatalytic process. Kinetic studies showed that apparent reaction rate constants in the sonophotocatalytic system of PCN-222(M) are 1.5-3.3 times higher than those in photocatalysis. Fluorescence and UV-vis absorption spectra measurements demonstrate that the sonophotocatalytic process promotes the transfer of photoinduced electrons from PCN-222(M) to Cr(VI), thus enhancing the catalytic performance. The innovative combination of porous MOFs and sonophotocatalytic technology might become a feasible strategy to improve the existing MOF-based photocatalytic systems.

Hydrothermal synthesis of N-doped carbon quantum dots and their application in ion-detection and cell-imaging.

Carbon quantum dots (CQDs), owing to their characteristic luminescent properties, have become a new favorite in the field of luminescence. They have been widely used in light emitting diode, ion detection, cell-imaging, ect. Herein a facile synthesis method of nitrogen-doped carbon quantum dots (N-CQDs) has been developedviaa one-step hydrothermal of glucose and m-phenylenediamine. The chemical composition, surface functional groups, and crystal structure of so prepared N-CQDs were systematically characterized. The characterizations indicate that nitrogen has been chemically doped in the CQDs and the N-CQDs crystallize in a graphene structure. Photoluminescence (PL) measurements show that the N-CQDs emit strong blue emission under the irradiation of ultraviolet. The emission is excitation-dependent, is resistant to photo bleaching and high ionic strength, and slightly decreases with the increase of temperature. The quantum yield of them is about 17.5%. The PL intensity of N-CQDs quenches linearly with the increase of the concentrations of Fe3+(0.5-1.0 mM) and CrO42-(0.3-0.6 mM), which are a kind of excellent fluorescent probe for the detection of Fe3+ and CrO42-. The quenching mechanism of Fe3+ and CrO42-is verified to be a static quenching mechanism based on inner filter effect. The N-CQDs are also found to be a good cell-imaging reagent of Hela cells.

Eosin Y-Embedded Zirconium-Based Metal-Organic Framework as a Dual-Emitting Built-In Self-Calibrating Platform for Pesticide Detection.

A series of eosin Y (EY)-embedded zirconium-based metal-organic frameworks (Zr-MOFs) were prepared by utilizing the synthetic encapsulating method. By virtue of effective resonant energy transfer between Zr-MOF and EY, not only does EY@Zr-MOF exhibit dual-emissive characteristics, but also the relative intensity of their double emission is greatly tuned with increasing EY loading quantity. As a consequence, the double emission of EY@Zr-MOF presented large distinctions in location and intensity. By using the relative fluorescence intensity instead of the absolute fluorescence intensity of emission peaks as detection signals, two EY@Zr-MOFs served as built-in self-calibrated fluorescence sensors to detect pesticides, where EY@Zr-MOF realized the selective detection of nitenpyram, a kind of nicotine pesticide. These results indicate that the integration of robust Zr-MOF and fluorescence molecules provides a new research platform for pesticide sensing and recognition.

RhB-Embedded Zirconium-Naphthalene-Based Metal-Organic Framework Composite as a Luminescent Self-Calibrating Platform for the Selective Detection of Inorganic Ions.

A series of dye@MOF composites were synthesized through in situ encapsulation of luminous rhodamine B (RhB) molecules into a blue-emissive zirconium-naphthalene-based metal-organic framework (Zr-MOF). The fabricated RhB@Zr-MOF composites exhibit tunable dual-emissive characteristics due to the process of resonant energy transfer from Zr-MOF to RhB. Notably, one of the RhB@Zr-MOF composites (R@D3) exhibited a weak emission at 420 nm and a strong emission at 607 nm, for which the two emissions possess large distinctions in location and intensity and can be referenced with each other in sensing analytes. By using relative fluorescence intensity instead of their absolute fluorescence intensity as the detection signals, R@D3 served as a built-in self-calibrated platform to selectively detect Fe3+ and Cr2 O7 2- ions in water. Compared with the pristine Zr-MOF, the R@D3 composite shows enhanced sensing selectivity to Fe3+ and higher sensibility to Cr2 O7 2- . This study displays the advantages of combining organic dyes with robust Zr-MOFs in tuning fluorescence and sensing performance.

Enhancement of visible-light-driven CO2 reduction performance using an amine-functionalized zirconium metal-organic framework.

By employing a conjugated amine-functionalized dicarboxylic ligand (H2L = 2,2'-diamino-4,4'-stilbenedicarboxylic acid, H2SDCA-NH2), we have successfully synthesized and characterized a porous and visible light responsive zirconium metal-organic framework ([Zr6O4(OH)4(L)6]·8DMF, denoted as Zr-SDCA-NH2). This Zr-MOF showed good chemical stability and broad visible light absorption with an absorption edge at about 600 nm. When used as a photocatalyst, Zr-SDCA-NH2 exhibits visible-light activity for CO2 reduction with a formate formation rate of 96.2 µmol h-1 mmolMOF-1, which is higher than the series of reported amine-functionalized Zr-MOFs. Mott-Schottky measurements, photoluminescence study and photocatalytic experiments demonstrated that the Zr6 oxo cluster through the LMCT process and the organic ligand both contributed to the CO2 photoreduction. This study indicates that the combination of amino groups and highly conjugated molecules is a feasible and simple strategy to extend light absorption of the organic ligand, which is beneficial for designing a visible light responsive MOF photocatalyst.

Facile Fabrication of Well-Dispersed Pt Nanoparticles in Mesoporous Silica with Large Open Spaces and Their Catalytic Applications.

In this paper, a facile strategy is reported for the preparation of well-dispersed Pt nanoparticles in ordered mesoporous silica (Pt@OMS) by using a hybrid mesoporous phenolic resin-silica nanocomposite as the parent material. The phenolic resin polymer is proposed herein to be the key in preventing the aggregation of Pt nanoparticles during their formation process and making contributions both to enhance the surface area and enlarge the pore size of the support. The Pt@OMS proves to be a highly active and stable catalyst for both gas-phase oxidation of CO and liquid-phase hydrogenation of 4-nitrophenol. This work might open new avenues for the preparation of noble metal nanoparticles in mesoporous silica with unique structures for catalytic applications.

Electrical conductivity and electroluminescence of a new anthracene-based metal-organic framework with π-conjugated zigzag chains.

A new three-dimensional microporous MOF has been constructed using a highly conjugated anthracene-based ligand. The rarely occurring long-range π-stacking of the ligand in the form of a zigzag chain has been found in the MOF structure, which provides not only a new charge transport pathway with high electrical conductivity of 1.3 (±0.5) × 10(-3) S cm(-1) but also an electroluminescence property with an emission centred at 575 nm.