ACS Nano最新文献

{"title":"Charged Biexciton Formation with Many-Body-Induced Valley Polarization in a Monolayer Semiconductor","authors":"Qirui Liu, Ke Wei, Yuxiang Tang, Yingqian Ye, Siwei Li, Hongyun Yu, Zhichao Pan, Tian Jiang","doi":"10.1021/acsnano.5c01195","DOIUrl":"https://doi.org/10.1021/acsnano.5c01195","url":null,"abstract":"In the realm of many-body physics, the study of low-dimensional excitonic complexes has emerged as a compelling area of research, offering tunable modifications and highlighting quasiparticle interactions as key drivers for advancing valleytronics. Building upon extensive studies of simpler few-body systems such as excitons and trions, here we present a comprehensive exploration of the valley dynamics in more complex five-body charged biexciton (XX^–) in monolayer WS₂ using helicity-resolved ultrafast spectroscopy. We observe a near-unity degree of valley polarization at a moderate temperature of ∼150 K, which persists substantially longer than the population lifetime. Intriguingly, this polarization reveals an unexpected positive correlation with external disturbances such as temperature and pump fluence─behaviors distinct from conventional few-body systems. These phenomena are attributed to the inherent suppression of valley-exchange interactions in XX^–, combined with its dual formation mechanisms: direct optical excitation and indirect conversion mediated by trion–trion interactions. Our results demonstrate that multibody excitonic complexes are stable candidates for maintaining valley polarization and could enable valleytronic applications that utilize many-body correlations.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"59 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143723568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microscopic Mechanisms, Morphology, and Defect Formation in the Thermally Activated Crystallization of Methylammonium Lead Iodide","authors":"Simone Argiolas, Claudia Caddeo, Christian Tantardini, Jgor Pensè Schone, David Dell’Angelo, Alessio Filippetti, Alessandro Mattoni","doi":"10.1021/acsnano.4c14732","DOIUrl":"https://doi.org/10.1021/acsnano.4c14732","url":null,"abstract":"In this study, we unravel the atomistic mechanisms that govern the crystallization process of methylammonium lead iodide through the application of microsecond time scale molecular dynamics simulations.The findings indicate that methylammonium iodide (MAI) and lead iodide (PbI₂) precursors exhibit a propensity to aggregate into a disordered film, which ultimately undergoes a thermally activated disorder-to-order transformation to achieve crystallization. Notably, the crystal evolution during the annealing process reveals morphological characteristics consistent with the Straski–Krastanov growth mode. The temperature dependence of the crystal growth rate demonstrates an activation energy of 0.37 eV, which may be ascribed to the energy required to dissociate defective Pb–I bonds and facilitate Pb diffusion. Finally, the mechanisms underlying the spontaneous generation of lead vacancies are examined, suggesting a kinetic origin for such optically active defects. In principle, the latter suggests the potential for reducing their concentration through optimization of the growth parameters.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"29 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly Efficient and Stable Wide Band Gap Quasi-2D Perovskite Solar Cells via Interfacial Quantum Well Regulation","authors":"Nuanshan Huang, Daozeng Wang, Jun Fang, Xin Wang, Shaokuan Gong, Sibo Li, Guanshui Xie, Huan Li, Dongxu Lin, Lin Gan, Haichen Peng, Xihan Chen, Sisi He, Longbin Qiu","doi":"10.1021/acsnano.5c01589","DOIUrl":"https://doi.org/10.1021/acsnano.5c01589","url":null,"abstract":"Quasi-2D perovskites are known for their long-term environmental stability. In this system, bulky spacers are expected to inhibit ion migration and reduce interfacial nonradiative recombination. However, it also presents challenges for charge transportation at the same time. As a result, the possibility and great potential of such quasi-2D perovskites for wide band gap (WBG) solar cells have rarely been explored. Here, we specialize in formamidinium-based quasi-2D WBG perovskites, obtaining a preferential crystal orientation perovskite film. To obtain better performance, the interfacial quantum wells (QWs) regulation strategy for a higher preference of a low-dimensional perovskite interface layer is proposed. The interfacial QWs are adjusted by the preference binding capacity of the solvent and long-chain molecules. The importance of interfacial QW distribution for charge transportation and stability is further investigated in this work. The quasi-2D 1.70 eV perovskite solar cells achieved by the regulation strategy exhibit an efficiency of 20.18% with a <i>V</i>_OC of 1.27 V and maintain 95% initial performance under 1 sun illumination over 500 h of stable operation.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"29 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-Precision Biochemical Sensing with Resonant Monocrystalline Plasmonic Ag Microcubes in the Mid-Infrared Spectrum","authors":"Aidana Beisenova, Wihan Adi, Shinwon Kang, Kenzie B. Germanson, Simon Nam, Samir Rosas, Shovasis Kumar Biswas, Manish S. Patankar, Seog-Jin Jeon, Filiz Yesilkoy","doi":"10.1021/acsnano.5c00624","DOIUrl":"https://doi.org/10.1021/acsnano.5c00624","url":null,"abstract":"Infrared (IR) spectroscopic fingerprinting is a powerful analytical tool for characterizing molecular compositions across biological, environmental, and industrial samples through their specific vibrational modes. Specifically, when the sample is characterized in resonant plasmonic cavities, as in the surface-enhanced mid-IR absorption spectroscopy (SEIRAS), highly sensitive and specific molecular detection can be achieved. However, current SEIRAS techniques rely on nanofabricated subwavelength antennas, limited by low-throughput lithographic processes, lacking scalability to address broad biochemical sensing applications. To address this, we present an on-resonance SEIRAS method utilizing silver (Ag) cubic microparticles (Ag-CMPs) with robust mid-IR plasmonic resonances. These monocrystalline Ag-CMPs, featuring sharp edges and vertices, are synthesized via a high-throughput, wet-chemical process. When dispersed on gold mirror substrates with an aluminum oxide spacer, Ag-CMPs support enhanced near-field light–matter interactions in nanocavities while enabling far-field imaging-based optical interrogation due to their strong extinction cross sections. We demonstrate the detection of polydimethylsiloxane (PDMS) and bovine serum albumin (BSA) monolayers by simply probing individual Ag-CMPs, enabled by the resonant amplification of the characteristic vibrational absorptions. Furthermore, our single-particle SEIRAS (SP-SEIRAS) approach effectively analyzes complex human peritoneal fluid (PF) samples, eliminating the challenges of standard bulk sample measurements. This scalable and efficient SP-SEIRAS method addresses key limitations of IR spectroscopic fingerprinting techniques, unlocking possibilities for their widespread adoption in real-world biochemical sensing applications.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"57 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Catalytic Activation Function of Noble-Metal-Free High-Entropy Alloy for Enhancing SnO2 Acetone Detection Capability","authors":"Ou Wang, Zhiheng Ma, Zhenggang Xue, Muyu Yan, Bao-Li An, Yongmei Zhao, Jiaqiang Xu, Xiaohong Wang","doi":"10.1021/acsnano.5c00940","DOIUrl":"https://doi.org/10.1021/acsnano.5c00940","url":null,"abstract":"Enhancing the gas-sensing properties of metal oxide semiconductors using noble metals’ electronic and chemical sensitization functions is a common approach to develop high-performance gas sensors. However, the high cost and scarcity of noble metals pose challenges to sustainability. In this study, a non-noble metal MnFeCoNiCu high-entropy alloy (HEA) was designed as an alternative to noble metals to enhance the sensitivity of SnO₂ and enable efficient, stable, and rapid detection of acetone (C₃H₆O). The MnFeCoNiCu HEA-loaded SnO₂ demonstrated improved performance in C₃H₆O detection, including high selectivity (κ &gt; 3), a high sensitivity (<i>R</i>_a/<i>R</i>_g = 4.17 at 0.5 ppm), a low detection limit (30 ppb), fast response and recovery time (4.6 s/5 s), long-term stability (over 50 days), and resistance to humidity (stable at 90% RH). The enhanced performance of the HEA is attributed to the fact that it possesses more valence electrons and the electrons can transfer and redistribute among different atoms, which leads to an increase in active oxygen species and catalytic sites, promoting electron sensitization. This study provides insights into designing and developing a highly catalytic, non-noble metal HEA for gas-sensing applications.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"12 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Decoupling Strategy to Separate Training and Inference with Three-Dimensional Neuromorphic Hardware Composed of Neurons and Hybrid Synapses","authors":"Jung-Woo Lee, See-On Park, Seong-Yun Yun, Yeeun Kim, Hyun Myung, Shinhyun Choi, Yang-Kyu Choi","doi":"10.1021/acsnano.4c18145","DOIUrl":"https://doi.org/10.1021/acsnano.4c18145","url":null,"abstract":"Monolithic 3D integration of neuron and synapse devices is considered a promising solution for energy-efficient and compact neuromorphic hardware. However, achieving optimal performance in both training and inference remains challenging as these processes require different synapse devices with reliable endurance and long retention. Here, we introduce a decoupling strategy to separate training and inference using monolithically integrated neuromorphic hardware with layer-by-layer fabrication. This 3D neuromorphic hardware includes neurons consisting of a single transistor (1T-neuron) in the first layer, long-term operational synapses composed of a single thin-film transistor with a SONOS structure (1TFT-synapses) in the second layer for inference, and durable synapses composed of a memristor (1M-synapses) in the third layer for training. A 1TFT-synapse, utilizing a charge-trap layer, exhibits long retention properties favorable for inference tasks. In contrast, a 1M-synapse, leveraging anion movement at the interface, demonstrates robust endurance for repetitive weight updates during training. With the proposed hybrid synapse architecture, frequent training can be performed using the 1M-synapses with robust endurance, while intermittent inference can be managed using the 1TFT-synapses with long-term retention. This decoupling of synaptic functions is advantageous for achieving a reliable spiking neural network (SNN) in neuromorphic computing.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"35 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"2-Nitroimidazole-Functionalized Superparamagnetic Iron Oxide Nanoparticles Detect Hypoxic Regions of Glioblastomas on MRI and Improve Radiotherapy Efficacy","authors":"Yuki Yoshino, Fumi Yoshino, Ichio Aoki, Yasuyuki Mori, Gen Suzuki, Shunichiro Tsuji, Tsukuru Amano, Akihiko Shiino, Tokuhiro Chano, Yoshio Furusho, Takashi Murakami, Hideya Yamazaki, Kei Yamada","doi":"10.1021/acsnano.4c06753","DOIUrl":"https://doi.org/10.1021/acsnano.4c06753","url":null,"abstract":"The presence of hypoxic regions in tumors is associated with malignancy and is an important target for the high-precision diagnosis and treatment of tumors. Radioresistant hypoxic regions can be precisely identified and treated without the use of high doses of radiation if hypoxic region-specific contrast agents have a therapeutic effect. In this study, we synthesized a therapeutic-diagnostic complex agent (SPION-PG-NI) by combining polyglycerol-functionalized superparamagnetic iron oxide nanoparticles (SPION-PG, core diameter of 8.8 ± 1.9 nm) as an MRI contrast agent and 2-nitroimidazole (NI, a pimonidazole derivative) as a hypoxia-targeted ligand to visually evaluate hypoxic regions using MRI and improve radiotherapy efficacy at those sites. SPION-PG-NI showed a concentration-dependent contrast effect and had significantly higher accumulation in subcutaneous glioblastomas than the control agent, SPION-PG, 24 h after administration. Immunohistological evaluations showed that the SPION-PG-NI-accumulated regions corresponded well to hypoxic regions. SPION-PG-NI showed neither migration into the brain parenchyma nor neurotoxicity. Both SPION-PG and SPION-PG-NI decrease reactive oxygen species (ROS); however, they improve radiotherapy efficacy in hypoxic glioblastoma cells due to cytotoxicity. This effect of SPION-PG-NI was significantly higher than that of SPION-PG (<i>p</i> &lt; 0.01). After 12 Gy irradiation, the mean normalized glioblastoma tumor volume on day 38 in the SPION-PG-NI group (288%) was significantly lower than that in the control group (882%) (<i>p</i> &lt; 0.05). Collectively, these findings suggest the potential of SPION-PG-NI as a useful and safe tumor theranostic nanodevice for hypoxic imaging and improving radiotherapy efficacy.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"30 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Layered Metal–Organic Chalcogenides: 2D Optoelectronics in 3D Self-Assembled Semiconductors","authors":"Watcharaphol Paritmongkol, Zhifu Feng, Sivan Refaely-Abramson, William A. Tisdale, Christoph Kastl, Lorenzo Maserati","doi":"10.1021/acsnano.4c18493","DOIUrl":"https://doi.org/10.1021/acsnano.4c18493","url":null,"abstract":"Molecular self-assembly offers an effective and scalable way to design nanostructured materials with tunable optoelectronic properties. In the past 30 years, organic chemistry has delivered a plethora of metal–organic structures based on the combination of organic groups, chalcogens, and a broad range of metals. Among these, several layered metal–organic chalcogenides (MOCs)─including “mithrene” (AgSePh)─recently emerged as interesting platforms to host 2D physics embedded in 3D crystals. Their combination of broad tunability, easy processability, and promising optoelectronic performance is driving a renewed interest in the more general material group of “low-dimensional” hybrids. In addition, the covalent MOC lattice provides higher stability compared with polar materials in operating devices. Here, we provide a perspective on the rise of 2D MOCs in terms of their synthesis approaches, 2D quantum confined exciton physics, and potential future applications in UV and X-ray photodetection, chemical sensors, and electrocatalysis.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"3 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leveraging Vitamin C to Augment Nanoenabled Photothermal Immunotherapy","authors":"Wuxian Deng, Yiyuan Wang, Junyu Wang, Yitan Su, Mingyang Li, Kun Qu, Yucai Wang, Min Li","doi":"10.1021/acsnano.4c17080","DOIUrl":"https://doi.org/10.1021/acsnano.4c17080","url":null,"abstract":"Photothermal immunotherapy (PTI) is valuable for precise tumor targeting and immune activation. However, its efficacy is hindered by insufficient immune response, elevated antioxidant levels within tumor, and intrinsic tumor resistance mechanisms. This study introduces Vitamin C (VC), a widely available dietary nutrient, as an effective enhancer for PTI. High-dose VC induces oxidative imbalance in tumor cells, making them more susceptible to nanoenabled near-infrared-II photothermal therapy (NIR-II PTT) with the photosensitizer IR1080. The combination of VC and NIR-II PTT significantly amplifies antitumor immunity by upregulating CXCL16 expression and promoting CXCR6⁺ T cell infiltration. Clinical data reveal that higher CXCL16 and CXCR6 levels in human tumors correlate with improved survival and T cell infiltration, underscoring the translational potential of this approach. This study positions VC as a safe, accessible, and cost-effective dietary enhancer for PTI, reshaping the role of dietary nutrients in cancer therapy and offering a strategy for overcoming treatment resistance.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"72 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling the Assembly Transition of Diphenylalanine and Its Analogs: from Oligomer Equilibrium to Nanocluster Formation","authors":"Chang Liu, Yoav Dan, Ji Yun, Lihi Adler-Abramovich, Jinghui Luo","doi":"10.1021/acsnano.5c00433","DOIUrl":"https://doi.org/10.1021/acsnano.5c00433","url":null,"abstract":"Peptide self-assembly is fundamental to various biological processes and holds significant potential for nanotechnology and biomedical applications. Despite progress in understanding larger-scale assemblies, the early formation of low-molecular-weight oligomers remains poorly understood. In this study, we investigate the aggregation behavior of the self-assembling diphenylalanine (FF) peptide and its analogs. Utilizing single-nanopore analysis, we detected and characterized the low-molecular-oligomer formation of FF, <i>N</i>-<i>tert</i>-butoxycarbonyl-diphenylalanine (BocFF), fluorenylmethyloxycarbonyl-diphenylalanine (FmocFF), and fluorenylmethyloxycarbonyl-pentafluoro-phenylalanine (Fmoc-F₅-Phe) in real time. This approach provided detailed insights into the early stages of peptide self-assembly, revealing the dynamic behavior and formation kinetics of low-molecular-weight oligomeric species. Analysis revealed that the trimer is the key nucleus for FF, while the dimer is the primary nucleus for FmocFF and Fmoc-F₅-Phe aggregation, whereas both the dimer and trimer serve as nuclei for BocFF. Mass photometry was employed to track the evolution of these oligomers, revealing the transition from low- to high-molecular-weight species, thereby elucidating intermediate phases in the aggregation process. Transmission electron microscopy and Fourier transform infrared spectroscopy were further employed to characterize the final assembly states, offering high-resolution imaging of morphological structures and detailed information on secondary structures. Based on these analyses, we constructed a comprehensive graph that correlates the entire aggregation processes of the tested self-assembling peptides across multiple scales. This integrative approach provides a holistic understanding of peptide self-assembly, particularly in the formation of low-molecular-weight oligomers toward mature supramolecular structures. These findings shed light on their assembly pathways and structural properties, advancing our understanding of their assembly pathways for nanotechnology and biomedical applications.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"16 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}