Small Methods最新文献

Gas detection has become a popular research topic in the field of environmental protection and disease detection because of the concerning increase in environmental pollution and human health problems. 2D MXenes are promising candidates for room-temperature gas sensors because of their flexible and adjustable material compositions, high conductivities, high signal-to-noise ratios, and adjustable surface terminations. This paper presents the prospects of gas sensors, structure of MXenes, and potential sensing mechanisms of MXenes-based gas sensors. Applications of Ti₃C₂T_x, V₂CT_x, Nb₂CT_x, and Mo₂CT_x MXenes in gas sensors for the detection of different gases are reviewed, and the challenges and potential research directions for applying MXenes in gas sensors are discussed. This review provides ideas for designing novel sensitive materials by analyzing the potential value of MXenes-based gas sensors in the sensor field.

Precision phototherapy requires tight control over several therapeutic steps, which traditional methods often struggle to achieve. Here, this study reports an orthogonal trichromatic upconversion nanoparticle with a rather simple nanoarchitecture, NaErF₄@NaYbF₄@NaYbF₄:Nd@NaYF₄:Yb,Tm. Unlike conventional designs that rely on multiple activators and complicated multi-shelled structures (up to six nanoshells), the reported triple-shelled UCNPs utilize only two activator ions (Er³⁺ and Tm³⁺) but still enables to release red, green, and blue colors in response to three different NIR light excitations, thus significantly reducing structural complexity and synthetic workload. Integrating these UCNPs with photosensitizers and nitric oxide (NO) donors further achieve to a precision photodynamic therapy, which allows for step-wise control throughout the entire PDT process by independent activation of bioimaging, photochemical internalization, respiration prohibition via NO release, and ROS generation via specific light illuminations. Both in vitro and in vivo results demonstrate high efficiency of presented methodology, highlighting its great potential for NIR light-activated precision phototherapy.

Surface organic nanostructures demonstrate great potential across multidisciplinary fields ranging from molecular electronics to energy conversion and storage. In the regime of surface chemistry, their preparation generally relies on intrinsic components originally involved in the molecule-substrate systems to drive molecular assembly and reaction. The recent paradigm shift employs extrinsic components as functional mediators to precisely regulate nanostructure formation pathways and the resulting molecular nanostructures. This review highlights three categories of extrinsic modulators, including small gas molecules, metals, and their combinations, that allow the construction and modification of surface organic nanostructures through tailored assembly and reaction. In addition, their detailed roles and regulatory mechanisms at the single-molecule level are also discussed. This emerging extrinsic-components-mediated assembly and reaction methodology displayed herein enriches the preparation toolbox for surface organic nanostructures and further allows the modification of their physicochemical properties, opening new frontiers in supramolecular engineering, nanomaterials development, etc.

Metal halide perovskites (MHPs) show optoelectronic properties that are highly advantageous for light-emitting applications. Compared to polycrystalline (PC) perovskite, single-crystal (SC) perovskite exhibits high carrier mobility, reducing ion migration and suppressing Auger recombination. However, SC perovskite light-emitting diodes (SC-PeLEDs) face the following challenges: i) the growth of high-aspect-ratio SC films; ii) the interfacial contact between the SC light-emitting layers and the carrier transport layers. This review begins with the growth methods of MHP SC thin films. Then, the recent research progress of SC-PeLEDs is summarized, and the strategies for optimizing device performance are also reviewed. Finally, perspectives are proposed further to enhance the performance and practical application of SC-PeLEDs.

Spatial transcriptomics revolutionizes the understanding of tissue organization and cellular interactions by combining high-resolution spatial information with gene expression profiles. Existing spatial transcriptomics analysis platforms face challenges in accommodating diverse techniques, integrating multi-omics data, and providing comprehensive analytical workflows. STExplore, an advanced online platform, is developed to address these limitations. STExplore supports a wide range of technologies, including sequencing-based and image-based methods, and offers a complete analysis workflow encompassing preprocessing, integration with single-cell RNA sequencing (scRNA-seq), cluster-level and gene-level analyses, and cell-cell communication studies. The platform features dynamic parameter adjustments and interactive visualizations at each analytical stage, enabling users to gain deeper insights into the spatial transcriptomic landscape. Case studies on neurogenesis in embryonic brain development, Alzheimer's disease, and brain tissue architecture demonstrate STExplore's capabilities in enhancing gene expression analysis, revealing cellular spatial organizations, and uncovering intercellular communication patterns. STExplore provides a comprehensive and user-friendly solution for the expanding demands of spatial transcriptomics research. The platform is accessible at http://120.77.47.2:3000/.

Stabilizing oxidation state of Cu (Cu^δ+, δ > 0) sites is the key-enabling issue for electrocatalytic carbon dioxide (CO₂) reduction reaction (eCO₂RR) to multicarbon (C₂₊) products. The present study addresses this challenge by introducing cerium (Ce) doping into La₂CuO₄. The Ce doping facilitates f-d orbital coupling between Ce 4f and Cu 3d orbitals, suppressing electron enrichment around Cu atoms by transferring electrons from Cu 3d orbitals to Ce 4f orbitals via a Cu-O-Ce chain. These changes modulate the electronic structure of Cu, reduce the distance between neighboring Cu atoms, optimize the binding energy of surface-adsorbed CO (*CO), and lower the reaction energy barrier for *CO dimerization. As a result, the La_1.95Ce_0.05CuO₄ catalyst achieves a Faradaic efficiency up to 81% for C₂₊ products and maintains high stability over 50 h operation. This work highlights the unique role of Ce doping in stabilizing Cu^δ+ sites and hence enhancing C-C coupling, providing a pathway for designing efficient catalysts for eCO₂RR.

Oxide submicrospheres with a high refractive index are essential for enhancing scattering and manipulating light transmission at submicrometer scale in photonic applications. However, achieving precise control over the diameter and monodispersity of transition metal oxide submicrospheres remains challenging, due to the unclear formation mechanism and lack of effective synthesis strategy. Here, a nonclassical mechanism of oligomer aggregation for controllable synthesis of monodispersed ZrO₂ submicrospheres (ZS) with mean diameters ranging from 0.263 to 1.295 µm and polydispersity indices almost below 0.1 is presented. Oligomers are identified as the fundamental building units, and their aggregation behavior governs the formation of ZS. Moreover, the precise regulation of homogeneous oligomer formation and aggregation is achieved through the introduction of alkanoic acids and amines. This adjustment, driven by steric effect, hydrogen bonding strength, reaction priority, and quantity, enables control over spherical morphology, monodispersity, and diameter. Compared to SiO₂ and polystyrene submicrospheres, ZS exhibits enhanced, tunable scattering behavior and superior chemical stability. The findings suggest that the oligomer aggregation mechanism, along with its controllable strategy, provides a new framework for synthesizing monodispersed transition metal oxide submicrospheres, broadening the range of materials available for photonic applications.

The kinetics of Ho(III) extraction using di(2-ethylhexyl)phosphoric acid (D2EHPA) under the influence magnetic field are examined. The methodology for kinetics research is based on spectrophotometric techniques. Initial experiments without a magnetic field assess the influence of Ho(III) concentration (0.00625-0.1 m), pH (1-6), D2EHPA concentration (0.1-2 m), and temperatures (5-35 °C). Subsequent tests (5-35 °C) determine the influence of the magnetic field. Experimental considerations are supplemented with numerical simulations of the magnetic field affecting the extraction system. A white precipitate formed at the phase boundary is characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) techniques. Post-extraction solutions are analyzed with nuclear magnetic resonance (NMR) spectroscopy to investigate the structure and magnetic properties of the D2EHPA-Ho(III) complex. The conducted research indicate that magnetic fields notably enhance kinetics of extraction above 25 °C, suggesting a possible change in the extraction mechanism.

Aqueous zinc-ion batteries have emerged as promising candidates for large-scale energy storage, but their cycle stability is limited by irreversible zinc anodes due to dendrite growth and undesired side reactions. Here, an artificial composite protective layer consisting of a Zn metal-organic framework (MOF) layer infiltrated with a hydrophobic ionic liquid 1-ethyl-3-methylimidazoline bis(trifluoromethyl sulfonyl) imide is constructed on zinc anodes. The unique porous structure of the MOF enables uniform electric field distribution, effectively inducing uniform Zn plating and stripping. Meanwhile, a small amount of hydrophobic ionic liquid can effectively isolate the direct contact between the zinc anode and the aqueous electrolyte, thereby inhibiting undesired side reactions including hydrogen evolution reaction. In addition, the cations in the ionic liquid can act as a shielding layer to suppress the tip effect. Consequently, the stability of the zinc metal anode is greatly improved. The assembled symmetric cell is able to cycle stably for over 2600 h at 0.2 mA cm^-2/0.2 mAh cm^-2 and over 800 h at 1 mA cm^-2/1 mAh cm^-2, which also exhibits lower and more stable overpotentials.

It is highly desired to get rid of the high-temperature annealing process in manufacturing perovskite solar cells (PSCs) to reduce production costs. Herein, perovskite films are designed by rapidly evaporating of a mixture solvent consisting of methylamine ethanol solution (MA-EtOH sol) and acetonitrile (ACN) (MA-EtOH-ACN) by dopping different amounts of formamidinium iodide (FAI) into the CH₃NH₂PbI₃ (MAPbI₃) precursor solution; as a result, the high-temperature annealing step is effectively eliminated while the perovskite solar cell efficiency remains unchanged. The in situ UV-vis absorption for monitoring the perovskite crystallization process shows that FAI retards the crystallization rate, leading to a dense and smooth film. It is also found that the synergistic effect of solvent and composition engineering reduces defect density, boosts absorption strength, and enhances film stability. Consequently, high-performance ITO/SnO₂/FA_0.05MA_0.95PbI₃/carbon device is obtained with efficiency as high as 18.74%, with an excellent short circuit current of 25.04 mA cm^-2, an open circuit voltage of 1.16 V, and a fill factor of 64.53%. The carbon-based perovskite solar cells also exhibit outstanding stability. This strategy offers a reference to producing efficient and stable perovskite cells by the straightforward ink method.