Nano Research最新文献

Dry reforming of methane (DRM) can simultaneously convert two critical greenhouse gases CH₄ and CO₂ into high-value syngas. However, the catalyst deactivation caused by sintering and carbon deposition of Ni-based catalysts at high temperature is a significant problem to be solved for DRM industrialization. Herein, we represent a hierarchical Ni-La@S-1 catalyst for DRM reaction, showing high anti-sintering/coke capacity to improve DRM stability. The La and Ni nitrates were first grinded into the pores of SBA-15 followed by N₂-treatment; the sample was then recrystallized by a unique template assisted-uniformly dispersed strategy to obtain the hierarchical Ni-La@S-1 catalyst. This strategy achieves uniform encapsulation of stabilized Ni-La bimetallic nanoparticles in S-1 with high loading, exhibiting high DRM activity and stability at 700 °C and 36,000 mL·g⁻¹·h⁻¹. Moreover, La addition promoted CO₂ to form bidentate carbonate, a critical intermediate in DRM, which greatly ameliorated carbon deposition in Ni catalysts. This work offers promising clue for tailoring the industrial DRM catalysts.

Proteolysis targeting chimeras (PROTACs) have recently emerged as promising therapeutic agents for cancer therapy. However, their clinical application is considerably hindered by the poor membrane permeability and insufficient tumor distribution of PROTACs. Here we proposed a nanoengineered targeting strategy to construct a self-assembled affibody-PROTAC conjugate nanomedicine (APCN) for tumor-specific delivery of PROTACs. As proof of concept, a hydrophobic PROTAC MZ1 (a bromodomain-containing protein 4 degrader) was selected to couple with a hydrophilic affibody Z_HER2:342 (an affinity protein of human epidermal growth factor receptor 2, HER2) via a smart linker containing disulfide bond to form an amphiphilic Z_HER2:342-MZ1 conjugate. It spontaneously self-assembled into nanoparticles (Z_HER2:342-MZ1 APCN) in water. Upon the excellent targeting property of Z_HER2:342 and HER2 receptor-mediated endocytosis, Z_HER2:342-MZ1 APCN was accumulated in tumor sites and internalized by cancer cells effectively in vitro. Under the intracellular high level of glutathione (GSH), Z_HER2:342-MZ1 APCN released MZ1 to specifically degrade bromodomain-containing protein 4 (BRD4) and subsequently induced BRD4 deficiency-mediated apoptosis of cancer cells. By the tail-vein injection, Z_HER2:342-MZ1 APCN showed the outstanding tumor-specific targeting ability, drug accumulation capacity, enhanced BRD4 degradation and antitumor efficacy in vivo for an HER2-positive SKOV-3 tumor model. Such an affibody mediated nanoengineered strategy would facilitate the application of PROTACs for targeted cancer therapy.

Moiré superlattices based on twisted transition metal dichalcogenide (TMD) heterostructures have recently emerged as a promising platform for probing novel and distinctive electronic phenomena in two-dimensional (2D) materials. By stacking TMD monolayers with a small twist angle, these superlattices create a periodic modulation of the electronic density of states, leading to the formation of mini bands. These mini bands can exhibit intriguing properties such as flat bands, correlated electron behavior, and unconventional superconductivity. This review provides a comprehensive overview of recent progress in Moiré superlattices formed from twisted TMD heterostructures. It covers the theoretical principles and experimental techniques for creating and studying these superlattices, and explores their potential applications in optoelectronics, quantum computing, and energy harvesting. The review also addresses key challenges, such as improving the scalability and reproducibility of the fabrication process, emphasizing the exciting opportunities and ongoing hurdles in this rapidly evolving field.

The development of biosensors is gaining tremendous attention in various fields due to their extraordinary advantages, however, their sensitivity and accuracy are still challenging. Herein, we proposed a novel multifunctional nanocomposite Ce-MOF@PdNPs (MOF = metal-organic framework, PdNPs = Pd nanoparticles)-mediated triple-readout aptasensor for accurate and reliable detection of diethylstilbestrol (DES), in which Ce-MOF@PdNPs exhibited excellent peroxidase (POD)-like activity, fluormetric, and electro conductive properties. In addition, enzymes-assisted target recycling amplification was utilized to improve the sensitivity, that is the specific binding of aptamer and DES triggered an Exo III enzyme-assisted recycling reaction. The generated F-DNA was captured by the H3 strand linked to Ce-MOF@PdNPs immobilized on the electrode, exposing cleavage sites and activating the Nt.BbvCI enzyme-assisted recycling reaction, leading to the dissociation of Ce-MOF@PdNPs and a significant reduced electrochemical signal. The collected Ce-MOF@PdNPs solution also induced a proportional change in the color and fluorescence, achieving a colorimetric and fluormetric detection functionality. The detection limit under colorimetric mode was 0.16 and 0.76 ng/mL under fluorescence mode, and 0.87 pg/mL under electrochemical mode. This triple-readout aptasensor exhibits high sensitivity, selectivity and accuracy, providing a new idea for designing novel biosensing platforms for veterinary drug residue detection.

Coupling quantum dots (QDs) in S-scheme (referred to as QD-S-scheme) is an efficient approach for photocatalysis. However, a comprehensive review of S-scheme QDs heterojunction photocatalysts is, to the best of our knowledge, absent. Herein, a concise overview of the unique advantages and limitations of QDs in photocatalytic reactions, as well as the charge transfer mechanism of the S-scheme is first introduced. Secondly, a thorough summary and evaluation of the types and assembly strategies of QDs are presented, highlighting the pivotal role of the QD-S-scheme heterojunction interface in photocatalytic performance. Then, the characterization methods for the charge transfer from the bulk to the interface and surface are discussed from the perspectives of the built-in electric field (BEF), steady-state and transient charge transfer processes, and photochemical reactions. And the design principles and optimization strategies for surface modulation, interface construction, and heterojunction design are also illustrated. Finally, insights on the current research status, challenges, and prospects of the QD-S-scheme are presented to contribute the development of QD-S-scheme heterojunction photocatalysts.

Exosomes are a kind of nanoscale membrane vesicles that can be secreted by many types of cells in both normal and pathological states and play a very important role in intercellular information exchange and transmission by transporting proteins, nucleic acids, lipids, and other biologically active substances to act on the receptor cells. Recent studies have shown that exosomes from some plants, animals, microorganisms, and other food sources can also be extracted like the structure of exosomes secreted by mammalian cells, which are named food-derived exosomes (FDEs) and can be absorbed by intestinal cells and further transported to other organs through blood circulation. With the advantages of high biocompatibility, low immunogenicity, low toxicity, high cargo capacity, and the ability to cross biological barriers, FDEs can be involved in a variety of applications such as immune response, cell migration, and tumor invasion, and have attracted a lot of attention as biotherapeutic agents and drug delivery carriers in the treatment of human diseases. This article reviews the classification, preparation characterization, physiological processes in the human body, biological functions, and application prospects of FDEs. It aims to provide a reference for the research and application of FDEs in disease treatment.

Developing emerging technologies in Internet of Things and artificial intelligence requires high-speed, low-power, high-sensitivity, and switchable-functionality strain sensors capable of sensing subtle mechanical stimuli in complex ambience. Resonant tunneling diodes (RTDs) are the good candidate for such sensing applications due to the ultrafast transport process, lower tunneling current, and negative differential resistance. However, notably enhancing sensing sensitivity remains one of the greatest challenges for RTD-related strain sensors. Here, we use piezotronic effect to improve sensing performance of strain sensors in double-barrier ZnO nanowire RTDs. This strain sensor not only possesses an ultrahigh gauge factor (GF) 390 GPa⁻¹, two orders of magnitude higher than these reported RTD-based strain sensors, but also can switch the sensitivity with a GF ratio of 160 by adjusting bias voltage in a small range of 0.2 V. By employing Landauer–Büttiker quantum transport theory, we uncover two primary factors governing piezotronic modulation of resonant tunneling transport, i.e., the strain-mediated polarization field for manipulation of quantized subband levels, and the interfacial polarization charges for adjustment of space charge region. These two mechanisms enable strain to induce the negative differential resistance, amplify the peak-valley current ratio, and diminish the resonant bias voltage. These performances can be engineered by the regulation of bias voltage, temperature, and device architectures. Moreover, a strain sensor capable of electrically switching sensing performance within sensitive and insensitive regimes is proposed. This study not only offers a deep insight into piezotronic modulation of resonant tunneling physics, but also advances the RTD towards highly sensitive and multifunctional sensor applications.

Pressure exerts a profound influence on atomic configurations and interlayer interactions, thereby modulating the electronic and structural properties of materials. While high pressure has been observed to induce a structural phase transition in bulk PdSe₂ crystals, leading to a transition from semiconductor to metal, the high-pressure behavior of few-layer PdSe₂ remains elusive. Here, employing diamond anvil cell (DAC) techniques and high-pressure Raman spectroscopy, we investigate the structural evolution of layer-dependent PdSe₂ under high pressure. We reveal that pressure significantly enhances interlayer coupling in PdSe₂, driving structural phase transitions from an orthorhombic to a cubic phase. We demonstrate that PdSe₂ crystals exhibit distinct layer-dependent pressure thresholds during the phase transition, with the decrease of transition pressure as the thickness of PdSe₂ increases. Furthermore, our results of polarized Raman spectra confirm a reduction in material anisotropy with increasing pressure. This study offers crucial insights into the structural evolution of layer-dependent van der Waals materials under pressure, advancing our understanding of their pressure-induced behaviors.