Nano Letters最新文献

Upconversion Phosphor-Driven Photodegradation of Plastics

IF 10.8 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Letters

Pub Date : 2024-10-22 DOI: 10.1021/acs.nanolett.4c04138

Shimao Deng, Runzi Cao, Xinjie Wang, Yuanhao Zhou, Jiaxin Liang, Huan Tang, Xuezhen Feng, Songhe Yang, Yangzi Shangguan, Yang Li, Hong Chen

Plastic waste poses a profound threat to ecosystems and human health, necessitating novel strategies for effective degradation in nature. Here, we present a novel approach utilizing upconversion phosphors as additives to significantly accelerate plastic photodegradation in nature via enhancing ultraviolet (UV) radiation. Pr-doped Li₂CaGeO₄ (LCGO:Pr) upconversion phosphors readily converting blue light into deep-UV radiation, dramatically improve photodegradation rates for polyethylene (PE) and polyethylene terephthalate (PET) microplastics. In situ spectroscopic studies show that upconversion fluorescence initiates the photophysical cleavage of C–C and C–O bonds in the backbones of PE and PET, resulting in plastic degradation. Moreover, incorporating LCGO:Pr into polypropylene (PP) sheets realizes markedly enhanced photodamage, with the cracking area increasing by nearly 38-fold under simulated sunlight for 10 days. This underscores the potential of employing this approach for the construction of light-driven destructible polymers. Further optimization and exploration of material compatibility hold promise for developing sustainable photodegradable plastics.

塑料废弃物对生态系统和人类健康构成了深远的威胁，因此有必要采取新颖的策略在自然界中进行有效降解。在这里，我们提出了一种利用上转换荧光粉作为添加剂的新方法，通过增强紫外线（UV）辐射来显著加速塑料在自然界中的光降解。掺杂 Pr 的 Li2CaGeO4（LCGO:Pr）上转换荧光粉能轻易地将蓝光转化为深紫外辐射，从而显著提高聚乙烯（PE）和聚对苯二甲酸乙二酯（PET）微塑料的光降解率。原位光谱研究表明，上转换荧光会引发聚乙烯和聚对苯二甲酸乙二醇酯骨架中 C-C 和 C-O 键的光物理裂解，从而导致塑料降解。此外，在聚丙烯（PP）片材中加入 LCGO:Pr 能显著增强光破坏效果，在模拟阳光下 10 天的开裂面积增加了近 38 倍。这凸显了采用这种方法制造光驱动可破坏聚合物的潜力。进一步优化和探索材料的兼容性为开发可持续光降解塑料带来了希望。

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引用次数: 0

Cryogels Composites: Recent Improvement in Bone Tissue Engineering

IF 10.8 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Letters

Pub Date : 2024-10-22 DOI: 10.1021/acs.nanolett.4c03197

Edgar J. Castanheira, João M. M. Rodrigues, João F. Mano

Autogenous bone grafts have long been considered the optimal choice for bone reconstruction due to their excellent biocompatibility and osteogenic properties. However, their limited availability and associated donor site morbidity have led to exploration of alternative bone substitutes. Cryogels, with their interconnected porosity, shape recovery, and enhanced mass transport capabilities, have emerged as a promising polymer-based solution. By incorporating bioactive glasses and nanofillers, cryogel composites offer bioactivity, cost-efficiency, and easy cell integration. This approach not only enhances bone regeneration but also underscores the broader role of nanotechnology in regenerative medicine. This mini-review discusses the advancement of organic–inorganic composites, focusing on biopolymeric cryogels and inorganic elements for reinforcement. We highlight how cryogels can be integrated into minimally invasive procedures, reducing patient distress and complications, and advanced 3D-printing techniques that enable further customization of these materials to mimic bone tissue architecture, offering potential for patient-specific treatments.

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引用次数: 0

An Mn-Enriched Interfacial Layer for Reversible Aqueous Mn Metal Batteries 用于可逆锰金属水电池的富锰界面层

IF 10.8 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Letters

Pub Date : 2024-10-22 DOI: 10.1021/acs.nanolett.4c03815

Zhichao Hou, Wenqiang Lu, Hongbao Zheng, Nan Chen, Heng Jiang, Dong Zhang, Fei Du

Aqueous manganese metal batteries have emerged as promising candidates for stationary storage due to their natural abundance, safety, and high energy density. However, the high chemical reactivity and sluggish migration kinetics of the Mn metal anode induce a severe hydrogen evolution reaction (HER) and dendrite formation, respectively. The situation deteriorates in the low-concentration electrolyte especially. Here, we propose a novel approach to construct an Mn-enriched interfacial layer (Mn@MIL) on the Mn metal anode surface to address these challenges simultaneously. The Mn@MIL acts as a physical barrier to not only suppress HER but also accelerate the Mn²⁺ diffusion kinetics through the Mn²⁺ saturated interfacial layer to inhibit dendrite growth. Therefore, in the low-concentration electrolyte (1 M MnCl₂), the Mn||Mn symmetric cells and Mn||V₂O₅ full cells with high mass loading demonstrate promising cycling stability with minimal polarization and parasitic reactions, making them more suitable for practical applications in a smart grid.

水态金属锰电池因其天然丰富、安全和高能量密度而成为固定存储的理想候选材料。然而，金属锰阳极的高化学反应性和缓慢的迁移动力学分别会引起严重的氢演化反应（HER）和枝晶形成。这种情况在低浓度电解液中尤为严重。在此，我们提出了一种在锰金属阳极表面构建富锰界面层（Mn@MIL）的新方法，以同时应对这些挑战。Mn@MIL 作为一种物理屏障，不仅能抑制 HER，还能加速 Mn2+ 通过 Mn2+ 饱和界面层的扩散动力学，从而抑制枝晶的生长。因此，在低浓度电解液（1 MnCl2）中，Mn|||Mn 对称电池和高负载质量的 Mn|||V2O5 全电池表现出良好的循环稳定性，极化和寄生反应极少，更适合在智能电网中实际应用。

引用次数: 0

Superconducting Boride Nb₂IrB₂ with Variable and Tunable Stacking Behaviors of Two-Dimensional [Nb-Ir-Nb] Triangular Lattices. 具有二维 [Nb-Ir-Nb] 三角晶格可变和可调堆积行为的超导硼化物 Nb2IrB2。

IF 9.6 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Letters

Pub Date : 2024-10-22 DOI: 10.1021/acs.nanolett.4c04739

Hanbin Gao, Yang Song, Ning Guo, Qing-Qiao Fu, Yue Gong, Feiyu Li, Fangli Li, Liusuo Wu, Junjie Zhang, Er-Jia Guo, Lizhi Zhang, Qiang Zheng

In structures with special geometry lattices, variations in stacking sequences are ubiquitous, yielding many novel structures and functionalities. Despite a wealth of intriguing properties and wide-ranging applications, there remains a considerable gap in understanding the correlation between special geometry lattices and functionalities in borides. Here, we design and synthesize a new superconducting boride Nb₂IrB₂, with a body-centered orthorhombic structure, consisting of alternating two-dimensional [Nb-Ir-Nb] triple-triangular-lattice-layers and B fragment layers. Advanced aberration-corrected scanning transmission electron microscopy observations show variable stacking configurations between [Nb-Ir-Nb] triple-triangular-lattice layers that can be tuned through synthesis conditions. Density functional theory calculations reveal that the coherent low-energy boundary interface plane of {101} between [11̅1] and [010] domains is responsible for the variable stacking behaviors. Energetically favorable structures are thereby reasonably proposed, based on nanoscale imperfect structure units. These findings provide valuable insights for designing and exploring new structures and functionalities within boride systems involving special geometry lattices.

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引用次数: 0

Evidence for π-Shifted Cooper Quartets and Few-Mode Transport in PbTe Nanowire Three-Terminal Josephson Junctions 铂碲纳米线三端约瑟夫森结中的π移库珀四元组和少模传输证据

IF 10.8 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Letters

Pub Date : 2024-10-22 DOI: 10.1021/acs.nanolett.4c02414

Mohit Gupta, Vipin Khade, Colin Riggert, Lior Shani, Gavin Menning, Pim J. H. Lueb, Jason Jung, Régis Mélin, Erik P. A. M. Bakkers, Vlad S. Pribiag

Josephson junctions are typically characterized by a single phase difference across two superconductors. This conventional two-terminal Josephson junction can be generalized to a multiterminal device where the Josephson energy contains terms with contributions from multiple independent phase variables. Such multiterminal Josephson junctions (MTJJs) are being considered as platforms for engineering effective Hamiltonians with nontrivial topologies, such as Weyl crossings and higher-order Chern numbers. These prospects rely on the ability to create MTJJs with nonclassical multiterminal couplings in which only a few quantum modes are populated. Here, we demonstrate these requirements in a three-terminal Josephson junction fabricated on selective-area-grown (SAG) PbTe nanowires. We observe signatures of a π-shifted Josephson effect, consistent with interterminal couplings mediated by four-particle quantum states called Cooper quartets. We further observe a supercurrent coexistent with a non-monotonic evolution of the conductance with gate voltage, indicating transport mediated by a few quantum modes in both two- and three-terminal devices.

约瑟夫森结的典型特征是两个超导体之间存在单个相位差。这种传统的双端约瑟夫森结可以推广到多端设备，在这种设备中，约瑟夫森能量包含来自多个独立相位变量的贡献项。这种多端约瑟夫森结（MTJJ）正被视为具有非难拓扑结构（如韦尔交叉和高阶切尔数）的有效哈密顿工程平台。这些前景依赖于创造具有非经典多端耦合的 MTJJ 的能力，其中只有少数量子模式被填充。在这里，我们在选择性面积生长（SAG）碲镉铅纳米线上制造的三端约瑟夫森结中证明了这些要求。我们观察到了π偏移约瑟夫森效应的特征，这与称为库珀四元组的四粒子量子态介导的端间耦合是一致的。我们进一步观察到超电流与电导随栅极电压的非单调演化并存，这表明在两端和三端器件中都存在由少数量子模式介导的传输。

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引用次数: 0

Nanomagnetic Guidance Shapes the Structure–Function Relationship of Developing Cortical Networks 纳米磁导向塑造发育中皮质网络的结构-功能关系

IF 10.8 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Letters

Pub Date : 2024-10-21 DOI: 10.1021/acs.nanolett.4c03156

Connor L. Beck, Conner T. Killeen, Sara C. Johnson, Anja Kunze

In this study, we implement large-scale nanomagnetic guidance on cortical neurons to guide dissociated neuronal networks during development. Cortical networks cultured over microelectrode arrays were exposed to functionalized magnetic nanoparticles, followed by magnetic field exposure to guide neurites over 14 days in vitro. Immunofluorescence of the axonal protein Tau revealed a greater number of neurites that were longer and aligned with the nanomagnetic force relative to nonguided networks. This was further confirmed through brightfield imaging on the microelectrode arrays during development. Spontaneous electrophysiological recordings revealed that the guided networks exhibited increased firing rates and frequency in force-aligned connectivity identified through Granger Causality. Applying this methodology across networks with nonuniform force directions increased local activity in target regions, identified as regions in the direction of the nanomagnetic force. Altogether, these results demonstrate that nanomagnetic forces guide the structure and function of dissociated cortical neuron networks at the millimeter scale.

在这项研究中，我们对皮质神经元实施了大规模纳米磁引导，以引导发育过程中分离的神经元网络。在微电极阵列上培养的皮层网络暴露于功能化的磁性纳米粒子，然后在体外暴露于磁场以引导神经元14天。轴突蛋白 Tau 的免疫荧光显示，与非引导网络相比，更多的神经元在纳米磁力的作用下变长并对齐。在发育过程中，微电极阵列上的明视野成像进一步证实了这一点。自发电生理记录显示，通过格兰杰因果关系（Granger Causality）确定的力对齐连接中，引导网络的发射率和频率都有所提高。在具有不均匀力方向的网络中应用这种方法，会增加目标区域（即纳米磁力方向上的区域）的局部活动。总之，这些结果表明，纳米磁力能在毫米尺度上引导分离的皮层神经元网络的结构和功能。

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引用次数: 0

High-Resolution Distance Dependence Interrogation of Scanning Ion Conductance Microscopic Tip-Enhanced Raman Spectroscopy Enabled by Two-Dimensional Molybdenum Disulfide Substrates 利用二维二硫化钼基底实现扫描离子传导显微镜尖端增强拉曼光谱的高分辨率距离相关性探测

IF 10.8 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Letters

Pub Date : 2024-10-21 DOI: 10.1021/acs.nanolett.4c04200

Xing He, Abu Montakim Tareq, Kai Qi, Ylli Conti, Vincent Tung, Naihao Chiang

Scanning ion conductance microscopy (SICM) is a powerful surface imaging tool used in the electrolytic environment. Tip-enhanced Raman spectroscopy (TERS) can give more information in addition to the morphology provided by the SICM by utilizing label-free Raman spectroscopy aided by the localized plasmonic enhancement from the metal-coated probes. In this study, the integration of SICM with TERS is demonstrated through employing a silver-coated plasmonic nanopipette. Leveraging a two-dimensional (2D) molybdenum disulfide (MoS₂) as a model system, the SICM-TERS enhancement factor was estimated to be ∼10⁵, supported by finite-difference time-domain (FDTD) simulation. Moreover, the subnanometer distance dependence SICM-TERS study reveals the tensile stress and structural changes caused by the nanopipette. These findings illustrate the potential of SICM-TERS for providing comprehensive morphological and chemical insights into electrolytic environments, paving the way for future investigations of electrocatalytic and biological systems.

扫描离子电导显微镜（SICM）是一种用于电解环境的强大表面成像工具。尖头增强拉曼光谱（TERS）通过利用金属涂层探针的局部等离子增强作用辅助无标记拉曼光谱，可以在扫描离子电导显微镜提供的形貌信息之外提供更多信息。在本研究中，通过使用银涂层质子纳米管，展示了 SICM 与 TERS 的整合。以二维（2D）二硫化钼（MoS2）为模型系统，通过有限差分时域（FDTD）模拟，估计 SICM-TERS 增强因子为 105。此外，与亚纳米距离相关的 SICM-TERS 研究揭示了纳米吸管引起的拉伸应力和结构变化。这些发现说明了 SICM-TERS 在提供有关电解环境的全面形态和化学见解方面的潜力，为今后研究电催化和生物系统铺平了道路。

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引用次数: 0

Quantitative Analysis of Protein–Protein Equilibrium Constants in Cellular Environments Using Single-Molecule Localization Microscopy 利用单分子定位显微镜定量分析细胞环境中的蛋白质-蛋白质平衡常数

IF 10.8 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Letters

Pub Date : 2024-10-21 DOI: 10.1021/acs.nanolett.4c04394

Luis F. Marcano-García, Cecilia Zaza, Olivia P. L. Dalby, Megan D. Joseph, M. Victoria Cappellari, Sabrina Simoncelli, Pedro F. Aramendía

Current methods for determining equilibrium constants often operate in three-dimensional environments, which may not accurately reflect interactions with membrane-bound proteins. With our technique, based on single-molecule localization microscopy (SMLM), we directly determine protein–protein association (K_a) and dissociation (K_d) constants in cellular environments by quantifying associated and isolated molecules and their interaction area. We introduce Kernel Surface Density (ks-density,) a novel method for determining the accessible area for interacting molecules, eliminating the need for user-defined parameters. Simulation studies validate our method’s accuracy across various density and affinity conditions. Applying this technique to T cell signaling proteins, we determine the 2D association constant of T cell receptors (TCRs) in resting cells and the pseudo-3D dissociation constant of pZAP70 molecules from phosphorylated intracellular tyrosine-based activation motifs on the TCR-CD3 complex. We address challenges of multiple detection and molecular labeling efficiency. This method enhances our understanding of protein interactions in cellular environments, advancing our knowledge of complex biological processes.

目前确定平衡常数的方法通常在三维环境中运行，可能无法准确反映与膜结合蛋白的相互作用。我们的技术以单分子定位显微镜（SMLM）为基础，通过量化关联分子和分离分子及其相互作用面积，直接测定细胞环境中的蛋白质-蛋白质关联常数（Ka）和解离常数（Kd）。我们引入了核表面密度（ks-density），这是一种确定相互作用分子可接触面积的新方法，无需用户定义参数。模拟研究验证了我们的方法在各种密度和亲和力条件下的准确性。将该技术应用于 T 细胞信号蛋白，我们确定了静息细胞中 T 细胞受体 (TCR) 的二维结合常数，以及 pZAP70 分子与 TCR-CD3 复合物上基于磷酸化细胞内酪氨酸的激活基团的伪三维解离常数。我们解决了多重检测和分子标记效率的难题。这种方法增强了我们对细胞环境中蛋白质相互作用的理解，促进了我们对复杂生物过程的认识。

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引用次数: 0

Structure-Guided Bacteria Specificity and Wide Activity Spectrum of Endotoxin-Responsive Peptide Nanonets 内毒素响应肽纳米网的结构引导细菌特异性和广泛活性谱

IF 10.8 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Letters

Pub Date : 2024-10-21 DOI: 10.1021/acs.nanolett.4c03166

Nhan Dai Thien Tram, Jan Kazimierz Marzinek, Louis Perrin, Devika Mukherjee, Vanitha Selvarajan, Peter John Bond, Pui Lai Rachel Ee

Peptide nanonets offer a promising avenue for constructing anti-infective biomaterials. Our group recently reported innovative designs of synthetic BTT nanonets that fibrillate selectively in response to bacterial endotoxins. Herein, we delved deeper into the molecular interactions between our peptides and these bacteria-specific biomolecules, which is an aspect critically missing from major works in the field. Using microscopic and biophysical techniques, we identified phosphate moieties in endotoxins as being the most essential to the initiation of peptide fibrillation. This was strongly supported by molecular dynamics simulations in an outer membrane environment with variable states of phosphorylation. To support the claim over bacterial specificity, we demonstrated a lack of nanonet formation in the presence of various phosphate-containing biomolecules native to human biology. The structural importance of phosphate moieties among pathogenic strains strongly indicates a wide clinical spectrum of our peptides, which was experimentally verified.

肽纳米网为构建抗感染生物材料提供了一条前景广阔的途径。我们的研究小组最近报告了合成 BTT 纳米网的创新设计，这种纳米网在细菌内毒素的作用下会选择性地纤维化。在此，我们深入研究了我们的肽与这些细菌特异性生物分子之间的分子相互作用，这是该领域主要研究中严重缺失的一个方面。利用显微镜和生物物理技术，我们确定了内毒素中的磷酸分子是引发肽纤维化的最重要因素。在磷酸化状态可变的外膜环境中进行的分子动力学模拟有力地证明了这一点。为了支持细菌特异性的说法，我们证明了在人类生物学中存在各种含磷生物大分子的情况下，纳米网的形成并不存在。病原菌中磷酸盐分子结构的重要性有力地说明了我们的多肽具有广泛的临床应用范围，这一点已得到实验验证。

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引用次数: 0

Salmonella Biomimetic Nanoparticles for Photothermal-Chemotherapy of Colorectal Cancer 用于大肠癌光热化疗的沙门氏菌仿生纳米粒子

IF 10.8 1区材料科学 Q1 CHEMISTRY, MULTIDISCIPLINARY

Nano Letters

Pub Date : 2024-10-21 DOI: 10.1021/acs.nanolett.4c04609

Ruichi Liu, Yunqiu Miao, Keyi Wen, Yang Yang, Dan Xu, Shengwei Lu, Ziyuan Liu, Huanlong Qin, Xinxin Zhang, Yang Zhang

Nanomedicines have been widely used in colorectal cancer treatment, but their suboptimal targeting and deficient penetration capabilities remain obstacles in the delivery of therapeutics. In this study, inspired by the natural tumor tropism and intestinal invasion of Salmonella, we engineered highly biomimetic nanoparticles (SM-AuNRs) utilizing a Salmonella membrane to coat bacilliform Au nanorods. The engineered SM-AuNRs were able to mimic the germ’s morphology and biological surface. SM-AuNRs containing the specific proteins inherited from the Salmonella membrane facilitated specific targeting and internalization into tumor cells. Meanwhile, SM-AuNRs with the rod-shaped morphology effectively traversed mucus barriers and tumor stroma. Due to the superior biological barrier penetrating and tumor targeting capabilities, doxorubicin-loaded SM-AuNRs with near-infrared laser irradiation displayed remarkable photothermal-chemotherapeutic antitumor effects in mouse orthotopic colorectal cancer models. Our findings pave the way for the design of bacteria-mimicking nanoparticles, presenting a promising avenue for the targeting and efficient treatment of colorectal cancer.

纳米药物已被广泛应用于结直肠癌的治疗，但其不理想的靶向性和不足的渗透能力仍然是治疗药物输送的障碍。在这项研究中，我们从沙门氏菌的天然肿瘤滋养和肠道侵袭性中得到启发，利用沙门氏菌膜包覆金纳米棒，设计出高度仿生的纳米颗粒（SM-AuNRs）。工程化的 SM-AuNRs 能够模拟病菌的形态和生物表面。SM-AuNRs含有从沙门氏菌膜中继承的特异性蛋白质，有助于特异性靶向和内化到肿瘤细胞中。同时，具有杆状形态的 SM-AuNRs 能有效穿越粘液屏障和肿瘤基质。由于SM-AuNRs具有卓越的生物屏障穿透能力和肿瘤靶向能力，在近红外激光照射下，负载了多柔比星的SM-AuNRs在小鼠正位结直肠癌模型中显示出显著的光热化学治疗抗肿瘤效果。我们的研究结果为设计仿菌纳米粒子铺平了道路，为靶向和高效治疗结直肠癌提供了一条前景广阔的途径。

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引用次数: 0