Small Methods最新文献

Tetrahedral framework nucleic acids (tFNAs) are renowned for their controllable self-assembly, exceptional programmability, and excellent biocompatibility, which have led to their widespread application in the biomedical field. Beyond these features, tFNAs demonstrate unique chemical and biological properties including high cellular uptake efficiency, structural bio-stability, and tissue permeability, which are derived from their distinctive 3D structure. To date, an extensive range of tFNA-based nanostructures are intelligently designed and developed for various biomedical applications such as drug delivery, gene therapy, biosensing, and tissue engineering, among other emerging fields. In addition to their role in drug delivery systems, tFNAs also possess intrinsic properties that render them highly effective as therapeutic agents in the treatment of complex diseases, including arthritis, neurodegenerative disorders, and cardiovascular diseases. This dual functionality significantly enhances the utility of tFNAs in biomedical research, presenting valuable opportunities for the development of next-generation medical technologies across diverse therapeutic and diagnostic platforms. Consequently, this review comprehensively introduces the latest advancements of tFNAs in the biomedical field, with a focus on their benefits and applications as drug delivery nanoplatforms, and their inherent capabilities as therapeutic agents. Furthermore, the current limitations, challenges, and future perspectives of tFNAs are explored.

To facilitate the development of efficient neuromorphic perception and computation, it is crucial to explore optoelectronic synaptic devices that integrate perceptual and computational capabilities. Various materials such as oxide semiconductors, conjugated organic polymers, transition metal sulfides, perovskite materials, and metal nanoparticles, along with their composites, are utilized in constructing these devices. However, optoelectronic synaptic devices based on 2D covalent organic frameworks (COFs) is rarely reported. In this study, an anthracene-based 2D COF (COF-DaTp) film is prepared using a room-temperature interface-confined strategy and utilized it as the active layer in an optoelectronic synaptic device with an Al/COF-DaTp/ITO configuration. The device demonstrated dual optoelectronic modulation, exhibiting significant optoelectronic resistive switching in response to light pulses, achieving 32 photoconductive states. Moreover, it exhibited history-dependent memristive behavior in voltage scans and electrical pulses, with a comparable diversity of 32 conductive states. The photodual-responsive properties of the COF-DaTp-based synaptic device enable it to simultaneously perform optical sensing and basic image denoising and recognition tasks, significantly enhancing recognition accuracy and reducing the number of training epochs compared to datasets without noise mitigation. This work opens the door for the application of 2D COF-based optoelectronic synaptic devices in visual computational processing.

Magnesium-sodium hybrid ion batteries (MSHIBs) are expected to achieve excellent rate capability. However, existing MSHIB cathodes exhibit low ionic conductivity and poor structural stability, resulting in low power density and cycle lifespan. Herein, sodium-rich Na_3.7V₆O₁₆·2.9H₂O (Na-rich NVO) nanobelts are synthesized as MSHIB cathodes. Excess Na⁺ induced NaO₅ and NaO₃ interlayer pins, which ensures NVO structural stability to accommodate Mg²⁺ and Na⁺. They also confine the migration pathway of cations to the diffusion direction, lowering the migration barriers of Mg²⁺ and enhancing the ionic conductivity. Excess interlayer Na⁺ increases the electronic conductivity of the involved Na-rich NVO cathode. The cathode exhibits a high Mg²⁺ diffusion coefficient, and the resulting MSHIBs exhibit a power density of 3.4 kW kg^-1 and a lifespan of 20 000 cycles at 5.0 A g^-1, with a capacity retention rate of 85%. Overall, this study paves the way for designing and developing fast-charging secondary batteries.

A full-color colorimetric humidity sensor with high brightness is proposed by using a hetero-structured dielectric film in a metal-insulator-metal (MIM) resonator. A humidity-responsive polymer is designed to graft on top of a metal-organic frameworks (MOFs) thin film (MOFs-Polymer) as insulator layer in the resonator. Programmable tuning of reflected color is achieved by controlling the polymer thicknesses, and finite difference time domain simulation of light-matter interactions at subwavelength scales proves the dependence of the reflected wavelength on dielectric layer thickness of the resonator. Vivid full-color changing is realized during tracking humidity process due to swelling of the stimuli-responsive polymer. Ultrafast response (≈0.75 s) is achieved for tracking trace H₂O from H₂O/methanol mixture, which is ≈10⁴ faster than that of the pure polymer-based MIM resonator. Meanwhile, the study observes significant spectral redshift because the porous MOFs film facilitates the preconcentration of external stimulus and improves the detection sensitivity of the resonator. Further, double-channel anti-counterfeiting multiplexing imaging is devised on the MIM resonator by photomask technology. Patterned encoding for security label is achieved on the MIM resonator by engineering humidity-tunable pixels of Au/MOFs-Polymer/Au and humidity-invalid pixels of Au/MOFs/Au.

Surface engineering of BiVO₄ photoanodes is effective and feasible for photoelectrochemical (PEC) water splitting. To achieve superior PEC performance, however, more than one surface engineering method is usually indispensable, for which a positive synergistic effect is vital and thus highly desired. Herein, it is reported that the incorporation of borate moieties into ultrathin p-type NiO_x catalysts can induce the reconfiguration of surface catalytic sites to form new highly active species, in addition to enhanced fast charge separation and transfer. The photocurrent density of BiVO₄ photoanodes is enhanced from 1.49 to 5.76 mA cm^-2 at 1.23 V versus reversible hydrogen electrode (RHE) under AM 1.5G illumination, which is achieved by successive modifications of NiO_x and borate moieties. It is found that BO₃ groups anchored to Ni atoms by replacing the surface hydroxyl sites of NiO_x catalysts not only increase the relative ratio of Ni³⁺ species to facilitate charge transfer but also provide efficient active sites for H₂O molecule adsorption and oxidation reactions. This work demonstrates the positive synergistic effect of these two surface engineering methods and provides an effective pathway to construct highly efficient and stable photoanodes for PEC water splitting.

A thiosemicarbazone-based iron(III) complex is prepared and used in the preparation of a supercapacitor electrode material. This electrode is produced by a solvothermal reaction of polypyrrole and the complex on carbon felt. The characterization of the complex and material is carried out using UV-vis, elemental analysis, FT-IR, XRD, BET, and TGA methods, and the surface morphology is examined using SEM technique. Because the interaction of electrode and electrolyte is of great importance in energy storage systems, as the surface area and pore volume increase, electrode ions at the electrode/electrolyte interface leak to the inner surfaces and interact with the larger surface area, which increases the charge storage performance. The electrode material, nano-worm structure, reached the highest specific capacitance value of 764.6 F g^-1 at 5 mV s^-1. Compared to the capacitance value of polypyrrole in its pure form, it is observed to exhibit an 187.2% increase. The highest specific capacitance value of the asymmetric supercapacitor (ASC) formed with a graphite electrode is 318.1 F g^-1 at the current density of 1 Ag^-1. Moreover, ASC reached a wide working potential of 1.8 V in an aqueous electrolyte and exhibited ultra-long cycle life (112%), maintaining its stability after 10 000 cycles.

Förster resonance energy transfer (FRET) plays a critical role in organic optoelectronic materials. However, developing facile and effective strategies to achieve high-efficiency energy harvesting of chromophores with aggregation-caused quenching (ACQ) remains an appealing yet challenging task, that has not yet been explored. Herein, a subtly strategy, crystallization-induced precise co-assembly (CIPCA) involving a molecular "lightening agent," to effectively improve FRET efficiency of ACQ chromophores is developed. Bis(phenylethynyl)anthracene (BPA) and bis(phenylethynyl)naphthacene (BPN) with significant ACQ effect are chosen as representative FRET donor and acceptor, respectively, and weakly-fluorescent octafluoronaphthalene (OFN) acted as the "lightening agent." Thanks to precise co-assembly with OFN, the PLQY of solid BPA is enhanced by 107%, and the BPN powder can be unprecedentedly lighted. More importantly, through such powerful CIPCA, the monotonous and weak emission for BPA@BPN can be remarkably regulated to colorful and much brighter ones with FRET efficiency improvement of as high as 180-270%. An in-depth understanding of FRET regulation is elucidated through a precise correlation of the supramolecular structures and properties. Such achievements allow to successfully fabricate distinct multi-stimuli-responsive fluorescent patterns and highly-emissive colorful flowers with high flexibility. This research provides an efficient strategy to improve the FRET efficiency of ACQ pairs.

Configurations of composite metal oxide nanoparticles are typically far off their thermodynamic equilibrium state. As such they represent a versatile but so far overlooked source material for the intergranular solid-state chemistry inside ceramics. Here, it is demonstrated how the admixture of Fe³⁺ and In³⁺ ions to MgO nanoparticles, as achieved by flame spray pyrolysis, can be used to engage ion exsolution, phase separation, and subsequent spinel formation inside the network of diamagnetic and insulating MgO grains. Extremely high uniformity in the distribution of intergranular ferrimagnetic MgFe₂O₄ films and grains with resulting magnetic coercivity values that depend on the nanoparticles' initial Fe³⁺ concentration is achieved. Moreover, percolating networks of semiconducting MgIn₂O₄ are derived from MgO nanoparticles with admixtures of 20 at% In³⁺ that gives rise to an enhancement of dc conductivity values by more than five orders of magnitude in comparison to the insulating MgO host. The here presented approach is general and applicable to the synthesis of a variety of functional spinel nanostructures embedded inside ceramic matrices. Nanoparticle loading with aliovalent impurity ions, the level of nanoparticle powder density after compaction, and sintering temperature are key parameters for this novel type of solid-state chemistry in between the host grains.

Heteroatom doping can change the chemical environment of carbon-based nanomaterials and improve their catalytic performance. Exploring the structure-catalytic activity relationship of heteroatom-doped carbon-based materials is of great significance for studying catalytic mechanisms and designing highly efficient catalysts, but remains a significant challenge. Recently, reactive oxygen species (ROS)-triggered electrochemiluminescence (ECL) has shown great potential for unveiling the mechanism by which heteroatom-doped carbon-based materials catalyze the oxygen reduction reaction (ORR), owing to the high sensitivity of these materials to the properties of the electrode surface. Herein, two kinds of heteroatom-doped porous carbon (denoted as NP-C and N-C) are synthesized and analyzed by monitoring the cathodic ECL of luminol-H₂O₂ in the low negative-potential region. P, N-doped NP-C exhibits better catalytic ability for activating H₂O₂ to generate large amounts of •OH and O₂ ^•-, compared with N-C. A sensitive antioxidant-mediated ECL platform is successfully developed for detecting the antioxidant levels in cells, exhibiting considerable potential for evaluating the antioxidant capacity. The relationship between the structure and catalytic mechanism of heteroatom-doped carbon-based materials is successfully explored using ECL, where this method can be universally applied to carbon-based materials.

Complex oxide thin films cover a range of physical properties and multifunctionalities that are critical for logic, memory, and optical devices. Typically, the high-quality epitaxial growth of these complex oxide thin films requires single crystalline oxide substrates such as SrTiO₃ (STO), MgO, LaAlO₃, a-Al₂O_3, and many others. Recent successes in transferring these complex oxides as free-standing films not only offer great opportunities in integrating complex oxides on other devices, but also present enormous opportunities in recycling the deposited substrates after transfer for cost-effective and sustainable processing of complex oxide thin films. In this work, the surface modification effects introduced on the recycled STO are investigated, and their impacts on the microstructure and properties of subsequently grown epitaxial oxide thin films are assessed and compared with those grown on the pristine substrates. Detailed analyses using high-resolution scanning transmission electron microscopy and geometric phase analysis demonstrate distinct strain states on the surfaces of the recycled STO versus the pristine substrates, suggesting a pre-strain state in the recycled STO substrates due to the previous deposition layer. These findings offer opportunities in growing highly mismatched oxide films on the recycled STO substrates with enhanced physical properties. Specifically, yttrium iron garnet (Y₃Fe₅O₁₂) films grown on recycled STO present different ferromagnetic responses compared to that on the pristine substrates, underscoring the effects of surface modification. The study demonstrates the feasibility of reuse and redeposition using recycled substrates. Via careful handling and preparation, high-quality epitaxial thin films can be grown on recycled substrates with comparable or even better structural and physical properties toward sustainable process of complex oxide devices.