化学最新文献

A cDNA sensor based on gold nanoparticles (Au) supported on nickel metal-organic framework nanosheets (MOF-NS) modified fluorine-tin oxide (FTO) glass electrode for the ultrasensitive and selective detection of miRNA-128 biomarker associated with the progression of Alzheimer's disease (AD) has been reported. The MOF-NS and Au nanoparticles were electrodeposited onto FTO electrode using chronoamperometry to immobilize 5'-biotinylated DNA (btn-cDNA) complementary to miRNA-128 by streptavidin-biotin interaction, generating the modified electrode (btn-cDNA/SV/Au/MOF-NS/FTO). The fabricated electrode was characterized using various surface characterization techniques, including FESEM, XPS, FTIR, and electrochemical methods. The fabricated electrode was then utilized for the selective detection of miRNA-128 using electrochemical impedance spectroscopy. The results indicated a linear response range of 1.0 × 10^-1 fM-1.0 × 10² nM with limit of detection of 0.017 fM, and sensitivity of 180.11 Ω fM^-1cm^-2. Moreover, the cDNA sensor showed satisfactory performance with real serum samples from AD patients and healthy individuals, as validated by real time-PCR technique with area under curve of 0.93 and a sensitivity of 90%, respectively, demonstrating the potential of present cDNA sensing approach in the biomedical field.

Triacylglycerols (TGs) represent one of the most abundant lipid classes in biological and food matrices; however, their structural characterization by mass spectrometry remains challenging because conventional workflows often provide only sum composition information. In the present study, an aza-Paternò-Büchi (aPB) derivatization strategy based on 6-azauracil was optimized and applied for negative-ion-mode, isomer-resolved analysis of TGs by high-resolution mass spectrometry. Reaction conditions were systematically investigated through solvent optimization, mixture design modeling, and kinetic studies. Moreover, the ionization and fragmentation behavior of aPB-derivatized TGs was comprehensively investigated, revealing distinct fragmentation pathways associated with charge localization effects in neutral lipids. Application to complex matrices demonstrated the feasibility of the approach, providing direct access to TG regioisomer distributions in human plasma and vegetable seed oils. Overall, the proposed strategy enables untargeted and double-bond-resolved annotation of TGs in complex matrices while maintaining straightforward sample preparation and compatibility with routine lipidomics workflows. For the first time, negative-ion mode was employed for TG annotation, expanding the molecular information accessible in TG lipidomics and food analysis.

This study introduces a novel rapid and efficient analytical approach for the determination of PGEs, excluding Os, in rock samples by ICP-MS. This approach combines effective matrix removal in silicate rock samples through the formation of insoluble fluorides during microwave-assisted digestion and the volatilization of silicon as SiF₄ with the capability of ICP-MS to quantify target isotopes at very low signal intensities (10-100 cps) using optimized acquisition parameters. Moreover, the ability to perform ICP-MS measurements at such low signal intensities also enables matrix reduction in other sample types, such as ores, through simple dilution while maintaining sufficient analytical sensitivity. Since proposed strategy employs fast microwave dissolution of PGEs together with their reliable and accurate determination, without the need for complex and time-consuming matrix-separation procedures such as ion-exchange chromatography or tellurium co-precipitation, the analytical workflow is significantly simplified, and the overall analysis time is reduced several-fold compared with conventional methods. At the same time, detection and quantitation limits are below 0.1 and 0.5 ng/g, respectively, for all analytes except Pd, for which the corresponding limits are 0.18 and 0.9 ng/g, enabling the determination of PGEs in variety rock types. The new method was verified using six rocks certified reference materials (CRMs) MUH-1 (harzburgite), NCS-DC73354/GBW07290 (peridotite), OKUM (komatiite), and UMT-1 (ultramafic ore tailings), WMS-1a (massive sulfide) and NCS-DC73356/GBW07292 (chromitite). The results obtained showed excellent agreement with both certified values and previously published data, with the vast majority of measurements falling within stated uncertainties or within ±10% of certified values.

Elucidating the effects of pollutants at the level of primary single cells is of great significance for an in-depth understanding of their health risks and toxicological mechanisms. N,N'-bis (1,4-dimethylpentyl)-p-phenylenediamine quinone (77PDQ) is an emerging environmental contaminant with multiple biological toxicities; however, its toxic effects at the primary single-cell level remain unexplored. In this study, we established a high-throughput single-cell metabolomics platform based on label-free CyESI-MS and applied it to the analysis of freshly isolated primary mouse liver cells for toxicological assessment of 77PDQ exposure at single-cell resolution. This strategy enabled us to capture cell-to-cell metabolic heterogeneity that was lost in conventional bulk measurements. Analysis of primary mouse liver cells revealed 181 significantly altered metabolites (|Log₂FC|>1, p < 0.05) following 77PDQ exposure. Pathway analysis demonstrated substantial disruptions in glycerophospholipid, arginine-proline, and beta-alanine metabolism. Eight lipid biomarkers (PC (41:6), PS (31:4), Cer (d41:1), TAG (53:2), LPG (18:1), SM (d42:3), FA (23:0), PA (36:2)) showed excellent diagnostic capacity (AUC>0.9). Our study provides the single-cell metabolomics evidence of 77PDQ hepatotoxicity and offers new mechanistic insights into this emerging environmental contaminant.

In this work, a high-performance, room-temperature-operated acetone gas sensor is developed based on cladding-modified optical fiber functionalized with hierarchical flower-like ZnO@Ag₂O nanostructures. Unlike conventional metal-oxide gas sensors operating at elevated temperatures, the formation of a p-n heterojunction between p-type Ag₂O and n-type ZnO facilitates efficient charge separation and significantly lowers the activation energy for acetone oxidation, enabling enhanced sensing at ambient conditions. The structural and morphological properties were characterized by X-ray diffraction, FESEM, XPS, and FTIR. The sensing performance was achieved by coating the modified fiber cladding with ZnO@Ag₂O, where evanescent-field interaction and adsorption-induced optical property changes govern the sensing mechanism, as validated by COMSOL Multiphysics simulations. The flower-like morphology provides a larger surface area and abundant active sites, resulting in superior sensing performance compared to pristine ZnO nps. The performance parameters of the developed sensor include a sensitivity of 11.37/ppm, a limit of detection of 0.85 ppm, and response and recovery times of 14 s and 60 s, respectively, compared to pristine ZnO nps. Additionally, the sensor exhibits good selectivity for acetone over different interfering VOC species. Owing to its spark-free operation, low power consumption, and immunity to electromagnetic interference, the proposed sensing platform presents a promising solution for real-time acetone detection in industrial process monitoring and non-invasive biomedical diagnostics.

Starbon derived from starch exhibits tunable surface functionality and high porosity, making them prominent candidates in energy storage technology. However, the poor fast-charging and limited stable-cycling properties of starbon limits the broad applications of lithium-ion batteries (LIBs) in practical scenarios. Herein, a boron-tailored approach was proposed to promote Li-ion migration and retard capacity decay of starbon anode. A boron solid-solution phase such as BC₂O was formed in the starbon framework by a simple pentaborate starch hydrothermal reaction and annealing process, and then boron quantum dots (BQDs) were confined within conductive boron-doped starbon. The electron-deficient BQDs endow the boronated starbon framework with superior electrochemical performance, vastly enabling the electrochemical activity of boron as well as providing more active sites for ion insertion and extraction, thus increasing capacity and improving ion charge/diffusion and transfer. As an anode material for LIBs, BQDs/Starbon anode exhibits a high discharge capacity of 928 mAh g^-1 at 0.05 A g^-1, and the reversible specific capacity remains at 238 mAh g^-1 at 2 A g^-1 after 1000 cycles, demonstrating excellent long-term cycling stability. After cycling at a high current density of 10 A g^-1 to recover to the initial 0.5 A g^-1, the electrode was still able to maintain a high capacity of 318 mAh g^-1. The excellent lithium storage properties demonstrated the composite anode of BQDs and biomass starbon is feasible, providing more choices for the development of anode materials for lithium-ion batteries.

Organic phenazine derivatives have emerged as promising materials for aqueous rechargeable batteries (ARBs) owing to their high theoretical capacity, molecular tunability and low cost. However, their practical application is largely constrained by poor intrinsic electronic conductivity and severe dissolution-induced capacity fading. Herein, a versatile dissolution-reprecipitation strategy is developed to construct highly integrated organic‑carbon nanocomposites for fast and durable aqueous K⁺ storage. Nano-sized dipyridophenazine (DPPZ) is conformally reprecipitated on Ketjen Black (KB), yielding a composite with intimate interfacial coupling and continuous electron pathways. As a result, the composite delivers exceptional high-rate capability and unprecedented cycling stability, retaining 99.9% of its initial capacity over 55,000 cycles at 50 A g^-1. Operando spectroscopic analyses, combined with density functional theory (DFT) calculations, reveal a highly reversible CN-K⁺ coordination mechanism, which governs the outstanding electrochemical behavior. Furthermore, full batteries employing Ni(OH)₂ cathodes deliver a high discharge capacity of 113 mAh g^-1 at 50 A g^-1 along with long-term durability, demonstrating record-level high-rate capability in aqueous K⁺ batteries. This work establishes a general and scalable strategy for advanced organic electrodes, offering a viable pathway toward safe, low-cost, and long-lifetime aqueous energy storage systems.

Cerium oxide (CeO₂) is one of the most effective catalysts for volatile organic compound (VOC) oxidation. However, the construction of ordered mesoporous CeO₂ architectures through sustainable synthesis routes remains highly challenging. Metal-organic frameworks (MOFs) are promising sacrificial templates for the synthesis of oxides. Herein, we report a surfactant-regulated, alkali-metal-assisted aqueous strategy to construct ordered mesoporous CeO₂ via UiO-66(Ce) templating. Pluronic was employed as a soft template, while inorganic bases (LiOH, NaOH, and KOH) were used to promote H₂BDC deprotonation in water. The Li⁺, Na⁺, and K⁺ cations are believed to influence the self-assembly of UiO-66(Ce) framework (CeULi, CeUNa, and CeUK, respectively), leading to differences in the properties of the resulting particles. CeO₂ derived from CeULi at low temperature, denoted as cCeULi, exhibited outstanding acetone conversion, reaching 90% at 207 °C. This is due to its mesoporous structure, the presence of Ce³⁺defects, and surface oxygen mobility. The cCeULi catalyst performed well over 10 cycles, averaging 87.9% efficiency over 25 h at 200 mg catalyst, 100 cc/min flow rate, and 600 ppm acetone. Also, cCeULi proved highly resistant to water vapor (5-10 vol%). In-situ DRIFTS analysis indicates that the acetone oxidation on cCeULi follows a Mars-van Krevelen mechanism involving lattice oxygen. Overall, the combination of morphological structure and surface chemical properties plays a key role in catalytic activity. This study is an important reference for the future development of ordered mesoporous CeO₂ derived from MOFs.

Room-temperature sodium‑sulfur (RT Na-S) batteries hold great promise for large-scale energy storage, yet they face severe challenges from polysulfide shuttling and sodium dendrite growth. To address these challenges, this study proposes an innovative strategy by introducing a boron-based additive, 2,4,6-trimethoxyboroxine (TMBX), into the propylene carbonate (PC)/NaClO₄ electrolyte to in-situ construct a boron-rich interphase. On the cathode side, the cathode electrolyte interface (CEI) layer is enriched with electron-deficient Lewis acidic B₂O₃, which chemisorbs soluble sodium polysulfides via BS and OS bonds. Simultaneously, this interphase forms a physical barrier due to its high mechanical strength and favorable structural properties, and the two effects work synergistically to suppress the shuttle effect. On the anode side, the inner solid electrolyte interface (SEI) layer that rich in boron-containing inorganic components can effectively inhibits sodium dendrite nucleation. Benefiting from the synergistic regulation of the boron-containing interphase, the TMBX-modified electrolyte endows Na-S cells with excellent performance. This work establishes a rational electrolyte design principle of leveraging boron-centered Lewis acidity for targeted polysulfide anchoring, coupled with a high-modulus interphase, offers a scalable and efficient strategy toward durable RT Na-S batteries.