Trigger Factor (TF) is a primary ATP-independent molecular chaperone in bacteria that engages nascent polypeptide chains emerging from the ribosomal exit tunnel to assist their folding. However, the real-time behavior of TF during active translation under near-physiological conditions remains elusive. Here, we employ high-speed atomic force microscopy (HS-AFM) imaging to visualize TF dynamics on intact Escherichia coli ribosomes in real time. We observe that TF transitions between compact and extended conformations and forms stable and transient contacts near ribosomal proteins uL23 and bL17, respectively. Interestingly, TFs engage distinct regions of the same ribosome-nascent chain complex, with one TF binding near the nascent chain and another near bL17, revealing multivalent interactions on the ribosome surface. Complementary all-atom molecular dynamics simulations reproduced the observed TF conformations and interaction dynamics, validating the experimentally observed structural transitions and dual-site engagement. This integrative approach uncovers previously inaccessible dynamics of ribosome-associated chaperones and offers a broadly applicable platform to probe cotranslational folding under near-physiological conditions.
{"title":"Multivalent Interactions between Chaperone and Ribosome-Nascent Chain Complex Revealed by High-Speed AFM and MD Simulations.","authors":"Eider Nuñez,Prithwidip Saha,Markel G Ibarluzea,Arantza Muguruza-Montero,Sara M-Alicante,Rafael Ramis,Aritz Leonardo,Aitor Bergara,Alvaro Villarroel,Felix Rico","doi":"10.1021/acsnano.5c13500","DOIUrl":"https://doi.org/10.1021/acsnano.5c13500","url":null,"abstract":"Trigger Factor (TF) is a primary ATP-independent molecular chaperone in bacteria that engages nascent polypeptide chains emerging from the ribosomal exit tunnel to assist their folding. However, the real-time behavior of TF during active translation under near-physiological conditions remains elusive. Here, we employ high-speed atomic force microscopy (HS-AFM) imaging to visualize TF dynamics on intact Escherichia coli ribosomes in real time. We observe that TF transitions between compact and extended conformations and forms stable and transient contacts near ribosomal proteins uL23 and bL17, respectively. Interestingly, TFs engage distinct regions of the same ribosome-nascent chain complex, with one TF binding near the nascent chain and another near bL17, revealing multivalent interactions on the ribosome surface. Complementary all-atom molecular dynamics simulations reproduced the observed TF conformations and interaction dynamics, validating the experimentally observed structural transitions and dual-site engagement. This integrative approach uncovers previously inaccessible dynamics of ribosome-associated chaperones and offers a broadly applicable platform to probe cotranslational folding under near-physiological conditions.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"8 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728653","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}
Disrupting mitochondrial calcium ion (Ca2+) homeostasis in tumor cells has emerged as a potent anticancer strategy, however, achieving precise, spatiotemporal control of mitochondrial Ca2+ overload poses a significant challenge. Herein, we present a bioinspired miRNA-responsive Ca2+ nanoregulator (Cu2O@Dz) that orchestrates endogenous ion flux through a multistage cascade to induce tumor-specific mitochondrial dysfunction. In this design, hairpin-structured DNAzymes (Dz) are conjugated to cuprous oxide (Cu2O) nanoparticles: within the acidic and H2O2-rich tumor microenvironment, the Cu2O core catalyzes site-specific Fenton-like reactions to generate hydroxyl radicals (•OH), which activate TRPA1 channels on the cell membrane and thereby trigger a robust influx of extracellular Ca2+. Concurrently, the Dz component functions as a dual-mode biosensor–actuator: recognition of overexpressed miRNA-21 produces a fluorescent signal for real-time diagnosis monitoring, while cleavage of miRNA-25 alleviates suppression of the mitochondrial calcium uniporter (MCU), thereby promoting mitochondrial Ca2+ uptake. The synergistic coupling of a TRPA1-mediated cytosolic Ca2+ surge with MCU-driven mitochondrial import establishes a unidirectional Ca2+ gradient, culminating in irreversible mitochondrial Ca2+ overload and potent tumor cell apoptosis. This work not only demonstrates an efficiently spatiotemporal coordination of dual ion-interference pathways for precision targeting but also establishes a versatile framework for organelle specific modulation of pathological ion fluxes in precision oncology.
{"title":"Bioinspired miRNA-Responsive Ca2+ Nanoregulator with Dual Interference Pathways and Self-Amplifying Cascade for Tumor-Targeted Mitochondrial Dysfunction","authors":"Jinkun Huang, Qin Xiang, Lei Shuai, Shuangshuang Yang, Jianglian Xu, Yaru Cheng, Youming Feng, Yufan Zhang, Zijia Zhou, Jiale Cheng, Youcong Gong, Jinze Li, Haifeng Dong","doi":"10.1021/acsnano.5c19706","DOIUrl":"https://doi.org/10.1021/acsnano.5c19706","url":null,"abstract":"Disrupting mitochondrial calcium ion (Ca<sup>2+</sup>) homeostasis in tumor cells has emerged as a potent anticancer strategy, however, achieving precise, spatiotemporal control of mitochondrial Ca<sup>2+</sup> overload poses a significant challenge. Herein, we present a bioinspired miRNA-responsive Ca<sup>2+</sup> nanoregulator (Cu<sub>2</sub>O@Dz) that orchestrates endogenous ion flux through a multistage cascade to induce tumor-specific mitochondrial dysfunction. In this design, hairpin-structured DNAzymes (Dz) are conjugated to cuprous oxide (Cu<sub>2</sub>O) nanoparticles: within the acidic and H<sub>2</sub>O<sub>2</sub>-rich tumor microenvironment, the Cu<sub>2</sub>O core catalyzes site-specific Fenton-like reactions to generate hydroxyl radicals (•OH), which activate TRPA1 channels on the cell membrane and thereby trigger a robust influx of extracellular Ca<sup>2+</sup>. Concurrently, the Dz component functions as a dual-mode biosensor–actuator: recognition of overexpressed miRNA-21 produces a fluorescent signal for real-time diagnosis monitoring, while cleavage of miRNA-25 alleviates suppression of the mitochondrial calcium uniporter (MCU), thereby promoting mitochondrial Ca<sup>2+</sup> uptake. The synergistic coupling of a TRPA1-mediated cytosolic Ca<sup>2+</sup> surge with MCU-driven mitochondrial import establishes a unidirectional Ca<sup>2+</sup> gradient, culminating in irreversible mitochondrial Ca<sup>2+</sup> overload and potent tumor cell apoptosis. This work not only demonstrates an efficiently spatiotemporal coordination of dual ion-interference pathways for precision targeting but also establishes a versatile framework for organelle specific modulation of pathological ion fluxes in precision oncology.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"14 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145718326","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}
Hend Mohamed Abdel-Bar, Steven Tandiono, Revadee Liam-Or, Calvin C. L. Cheung, Osama W. M. Hassuneh, Qingyang Lyu, Yue Qin, Shunping Han, Nadia Rouatbi, Julie Tzu-Wen Wang, Adam A. Walters, Khuloud T. Al-Jamal
Exosome lipid hybrid nanoparticles (ELNs) have emerged as promising drug delivery vehicles, integrating the innate targeting capabilities of exosomes with efficient cytosolic delivery of lipid nanoparticles. However, despite growing interest, the development of ELNs for nucleic acid delivery remains a formidable challenge, compounded by diverse production methods and a lack of systematic approaches to optimize their formulation and performance. This study employed a Box-Behnken design and two fabrication methods: freeze–thaw and sonication, to optimize the formulation of ELNs derived from exosomes of five distinct cancer cells. Formulation criteria focused on maximizing the fusion efficiency while minimizing particle size. The impact of the fusion method on cellular association and gene silencing of promising therapeutic targets, CD24, CD44, and CD47, was evaluated. The optimized formulations were subsequently assessed for therapeutic efficacy in 4T1 and B16F10 tumor models. Through careful manipulation of formulation variables, we obtained optimal ELNs with fusion efficiencies exceeding 50% and particle sizes under 170 nm while preserving exosomal markers CD9, CD63, and CD81. Cellular association studies revealed that ELNs specifically targeted their parental cell line, achieving ∼2.5-fold higher siRNA association compared to LNPs. Furthermore, the optimized ELNs facilitated the delivery of therapeutic siRNAs, resulting in robust gene silencing and consequently improved the in vitro macrophage-mediated phagocytosis of treated cancer cells. In vivo studies using 4T1 and B16F10 tumor models highlighted the enhanced therapeutic potential of the optimized ELNs, as evidenced by significant tumor targeting and growth inhibition. These findings underscore the importance of systematic formulation and method optimization in advancing ELNs as effective nucleic acid delivery platforms for cancer therapy.
{"title":"Optimizing Exosome Lipid Hybrid Nanoparticles for Enhanced siRNA Delivery and Improved Therapeutic Anticancer Efficacy In Vivo","authors":"Hend Mohamed Abdel-Bar, Steven Tandiono, Revadee Liam-Or, Calvin C. L. Cheung, Osama W. M. Hassuneh, Qingyang Lyu, Yue Qin, Shunping Han, Nadia Rouatbi, Julie Tzu-Wen Wang, Adam A. Walters, Khuloud T. Al-Jamal","doi":"10.1021/acsnano.5c16991","DOIUrl":"https://doi.org/10.1021/acsnano.5c16991","url":null,"abstract":"Exosome lipid hybrid nanoparticles (ELNs) have emerged as promising drug delivery vehicles, integrating the innate targeting capabilities of exosomes with efficient cytosolic delivery of lipid nanoparticles. However, despite growing interest, the development of ELNs for nucleic acid delivery remains a formidable challenge, compounded by diverse production methods and a lack of systematic approaches to optimize their formulation and performance. This study employed a Box-Behnken design and two fabrication methods: freeze–thaw and sonication, to optimize the formulation of ELNs derived from exosomes of five distinct cancer cells. Formulation criteria focused on maximizing the fusion efficiency while minimizing particle size. The impact of the fusion method on cellular association and gene silencing of promising therapeutic targets, CD24, CD44, and CD47, was evaluated. The optimized formulations were subsequently assessed for therapeutic efficacy in 4T1 and B16F10 tumor models. Through careful manipulation of formulation variables, we obtained optimal ELNs with fusion efficiencies exceeding 50% and particle sizes under 170 nm while preserving exosomal markers CD9, CD63, and CD81. Cellular association studies revealed that ELNs specifically targeted their parental cell line, achieving ∼2.5-fold higher siRNA association compared to LNPs. Furthermore, the optimized ELNs facilitated the delivery of therapeutic siRNAs, resulting in robust gene silencing and consequently improved the in vitro macrophage-mediated phagocytosis of treated cancer cells. In vivo studies using 4T1 and B16F10 tumor models highlighted the enhanced therapeutic potential of the optimized ELNs, as evidenced by significant tumor targeting and growth inhibition. These findings underscore the importance of systematic formulation and method optimization in advancing ELNs as effective nucleic acid delivery platforms for cancer therapy.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"170 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145718325","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}
Navod Thyashan,Janeesha Manawasinghe,Chaoming Gu,Santosh Khatri,Christopher Nelson,Merve Emecen Sanli,Steven J Gray,Sangyoup Lee,Prashanta Dutta,George Alexandrakis,Min Jun Kim
Adeno-associated virus (AAV) vectors are excellent gene-delivery carriers in gene therapy; however, improperly packaged capsids produced during manufacturing can reduce potency and raise safety concerns. We introduce a machine-learning-assisted, low-cost, label-free nanopore sensing platform with single-particle resolution to enhance AAV quality control. Using solid-state nanopore (SSN) devices on SixNy membranes, we optimized in vitro conditions for AAV9 detection and classification. We observed pH-dependent capsid denaturation under strong alkaline conditions. Buffer-specific, selective translocation of emptyAAV9 capsids from cargo-loaded samples enabled clear discrimination and revealed potential avenues for in situ filtration. We also observed distinct translocation behaviors between vectors encapsulating single-stranded DNA and those encapsulating self-complementary DNA. In addition, unsupervised clustering algorithms demonstrated high accuracy in distinguishing capsids with truncated genomes from those with full genomes, further facilitating AAV production quality. These findings support practical avenues for AAV filtration and analysis, providing a basis for label-free, high-throughput, precise, and scalable quality control in AAV vector manufacturing.
{"title":"Mechanisms of Adeno-Associated Virus Serotype 9 Vector Characterization and Quality Control through Solid-State Nanopores.","authors":"Navod Thyashan,Janeesha Manawasinghe,Chaoming Gu,Santosh Khatri,Christopher Nelson,Merve Emecen Sanli,Steven J Gray,Sangyoup Lee,Prashanta Dutta,George Alexandrakis,Min Jun Kim","doi":"10.1021/acsnano.5c16533","DOIUrl":"https://doi.org/10.1021/acsnano.5c16533","url":null,"abstract":"Adeno-associated virus (AAV) vectors are excellent gene-delivery carriers in gene therapy; however, improperly packaged capsids produced during manufacturing can reduce potency and raise safety concerns. We introduce a machine-learning-assisted, low-cost, label-free nanopore sensing platform with single-particle resolution to enhance AAV quality control. Using solid-state nanopore (SSN) devices on SixNy membranes, we optimized in vitro conditions for AAV9 detection and classification. We observed pH-dependent capsid denaturation under strong alkaline conditions. Buffer-specific, selective translocation of emptyAAV9 capsids from cargo-loaded samples enabled clear discrimination and revealed potential avenues for in situ filtration. We also observed distinct translocation behaviors between vectors encapsulating single-stranded DNA and those encapsulating self-complementary DNA. In addition, unsupervised clustering algorithms demonstrated high accuracy in distinguishing capsids with truncated genomes from those with full genomes, further facilitating AAV production quality. These findings support practical avenues for AAV filtration and analysis, providing a basis for label-free, high-throughput, precise, and scalable quality control in AAV vector manufacturing.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"152 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145728509","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}
Semiconductor nanowires are sensitive to the polarization of light due to their one-dimensional structure and high dielectric contrast to the surrounding medium. This phenomenon enables configurations of polarization-sensitive nanoscale devices that can be potentially integrated onto a chip. Here, we demonstrate a hybrid plasmonic perovskite nanolaser that exhibits unconventional polarization dependence. Typical plasmonic nanolaser designs utilize a metallic substrate and a low-index buffer layer material. In this study, we use a birefringent CsPbBr3 perovskite nanowire on a metal substrate separated by a thin Ta2O5 buffer layer, exhibiting a refractive index lower than that along the ordinary axes of the nanowire, but higher than that along the extraordinary axes. In these conditions, we experimentally show a lower lasing threshold when the incident field is orthogonally polarized, i.e., along the b-axis. This is due to stronger electric field confinement at the nanowire-buffer interface as shown in simulation when pumped by orthogonal polarized light. This polarization sensitivity is unique to the hybrid plasmonic configuration and is not observed in the photonic counterpart, such as a nanowire on a quartz substrate. Furthermore, we found that short plasmonic nanowires exhibit lower lasing thresholds in addition to a larger polarization dependence, contrary to longer plasmonic nanowires. Moreover, orthogonally polarized pumping induces a larger-emission blueshift than longitudinally polarized pumping, attributed to strong exciton-polariton interactions. This blueshift is pronounced in plasmonic nanowires with lower lasing thresholds. This polarization-sensitive plasmonic nanolaser with reduced lasing threshold has potential applications in nanophotonic integrated circuits and room-temperature perovskite polaritonics.
{"title":"Unconventional Polarization-Dependent Lasing Behavior in Birefringent CsPbBr3 Hybrid Mode Plasmonic Nanolasers.","authors":"Tik Lun Leung,Tzu-Yu Peng,Finn Harley Whitney,Helgi Sigurđsson,Yu-Jung Lu,Stevie Furxhiu,Girish Lakhwani,Christopher Bailey,Stefano Palomba,Anita Ho-Baillie","doi":"10.1021/acsnano.5c13252","DOIUrl":"https://doi.org/10.1021/acsnano.5c13252","url":null,"abstract":"Semiconductor nanowires are sensitive to the polarization of light due to their one-dimensional structure and high dielectric contrast to the surrounding medium. This phenomenon enables configurations of polarization-sensitive nanoscale devices that can be potentially integrated onto a chip. Here, we demonstrate a hybrid plasmonic perovskite nanolaser that exhibits unconventional polarization dependence. Typical plasmonic nanolaser designs utilize a metallic substrate and a low-index buffer layer material. In this study, we use a birefringent CsPbBr3 perovskite nanowire on a metal substrate separated by a thin Ta2O5 buffer layer, exhibiting a refractive index lower than that along the ordinary axes of the nanowire, but higher than that along the extraordinary axes. In these conditions, we experimentally show a lower lasing threshold when the incident field is orthogonally polarized, i.e., along the b-axis. This is due to stronger electric field confinement at the nanowire-buffer interface as shown in simulation when pumped by orthogonal polarized light. This polarization sensitivity is unique to the hybrid plasmonic configuration and is not observed in the photonic counterpart, such as a nanowire on a quartz substrate. Furthermore, we found that short plasmonic nanowires exhibit lower lasing thresholds in addition to a larger polarization dependence, contrary to longer plasmonic nanowires. Moreover, orthogonally polarized pumping induces a larger-emission blueshift than longitudinally polarized pumping, attributed to strong exciton-polariton interactions. This blueshift is pronounced in plasmonic nanowires with lower lasing thresholds. This polarization-sensitive plasmonic nanolaser with reduced lasing threshold has potential applications in nanophotonic integrated circuits and room-temperature perovskite polaritonics.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"1 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145711005","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}
Jack Harrison, Junxiong Hu, Charles Godfrey, Jheng-Cyuan Lin, Tim A. Butcher, Jörg Raabe, Simone Finizio, Hariom Jani, Paolo G. Radaelli
Antiferromagnetic materials are promising platforms for the development of ultrafast spintronics and magnonics due to their robust magnetism, high-frequency relativistic dynamics, low-loss transport, and the ability to support topological textures. However, achieving deterministic control over antiferromagnetic order in thin films is a major challenge due to the formation of multidomain states stabilized by competing magnetic and destressing interactions. Thus, the successful implementation of antiferromagnetic materials necessitates careful engineering of their anisotropy. Here, we demonstrate strain-based, robust control over multiple antiferromagnetic anisotropies and nanoscale domains in the promising spintronic candidate α-Fe2O3 at room temperature. By applying isotropic and anisotropic in-plane strains across a broad temperature–strain phase space, we systematically tune the interplay between magneto-crystalline and magneto-elastic interactions. We observe that strain-driven control steers the system toward an aligned antiferromagnetic state, while preserving topological spin textures, such as merons, antimerons, and bimerons. We directly map the nanoscale antiferromagnetic order using linear dichroic scanning transmission X-ray microscopy integrated with in situ strain and temperature control. A Landau model and micromagnetic simulations reveal how strain reshapes the magnetic energy landscape. These findings suggest that strain could serve as a versatile control mechanism to reconfigure equilibrium or dynamic antiferromagnetic states on demand in α-Fe2O3 for implementation in next-generation spintronic and magnonic devices.
{"title":"Room Temperature Control of Axial and Basal Antiferromagnetic Anisotropies Using Strain","authors":"Jack Harrison, Junxiong Hu, Charles Godfrey, Jheng-Cyuan Lin, Tim A. Butcher, Jörg Raabe, Simone Finizio, Hariom Jani, Paolo G. Radaelli","doi":"10.1021/acsnano.5c12282","DOIUrl":"https://doi.org/10.1021/acsnano.5c12282","url":null,"abstract":"Antiferromagnetic materials are promising platforms for the development of ultrafast spintronics and magnonics due to their robust magnetism, high-frequency relativistic dynamics, low-loss transport, and the ability to support topological textures. However, achieving deterministic control over antiferromagnetic order in thin films is a major challenge due to the formation of multidomain states stabilized by competing magnetic and destressing interactions. Thus, the successful implementation of antiferromagnetic materials necessitates careful engineering of their anisotropy. Here, we demonstrate strain-based, robust control over multiple antiferromagnetic anisotropies and nanoscale domains in the promising spintronic candidate α-Fe<sub>2</sub>O<sub>3</sub> at room temperature. By applying isotropic and anisotropic in-plane strains across a broad temperature–strain phase space, we systematically tune the interplay between magneto-crystalline and magneto-elastic interactions. We observe that strain-driven control steers the system toward an aligned antiferromagnetic state, while preserving topological spin textures, such as merons, antimerons, and bimerons. We directly map the nanoscale antiferromagnetic order using linear dichroic scanning transmission X-ray microscopy integrated with in situ strain and temperature control. A Landau model and micromagnetic simulations reveal how strain reshapes the magnetic energy landscape. These findings suggest that strain could serve as a versatile control mechanism to reconfigure equilibrium or dynamic antiferromagnetic states on demand in α-Fe<sub>2</sub>O<sub>3</sub> for implementation in next-generation spintronic and magnonic devices.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"7 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145711464","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}
Xiaofan Wei,Chengjiang Du,Le Kang,Ruirui Liu,Yi Zhao,Yanpeng Qi,John A. McGuire,Weimin Liu
Harnessing hot interlayer excitons (HIEs) in two-dimensional (2D) van der Waals (vdW) heterostructures offers a promising strategy for advancing hot-carrier optoelectronics beyond the Shockley–Queisser limit. However, the spatiotemporal diffusion dynamics and cooling behavior of HIEs remain poorly understood, particularly in transition metal dichalcogenide (TMD) bilayer heterostructures where moiré potentials significantly influence interlayer exciton transport. Here, we investigate a WSe2/WS2 bilayer heterostructure with a twist angle of ∼36°, a configuration that effectively suppresses moiré potential. We uncover a linear spatiotemporal diffusion behavior of interlayer excitons under weak moiré conditions─markedly different from the nonlinear dynamics typically observed in small-twist-angle systems (∼9°) dominated by strong moiré potentials. Furthermore, under above-bandgap excitation, we provide the direct experimental observation of the spatial diffusion of HIEs in a TMD bilayer heterostructure, a phenomenon that is difficult to observe in systems with strong moiré confinement. We demonstrate that the cooling time of HIEs is an order of magnitude longer than that of intralayer excitons in monolayer TMDs. This extended lifetime indicates the potential for efficient hot-carrier extraction in 2D heterostructures. Together, these findings offer insights into exciton transport and relaxation in moiré-engineered bilayer heterostructures and may inform the use of HIEs in optoelectronic and energy-harvesting applications.
{"title":"Spatiotemporal Cooling and Diffusion of Hot Interlayer Excitons in Moiré-Potential-Suppressed WSe2/WS2 Heterostructures","authors":"Xiaofan Wei,Chengjiang Du,Le Kang,Ruirui Liu,Yi Zhao,Yanpeng Qi,John A. McGuire,Weimin Liu","doi":"10.1021/acsnano.5c11799","DOIUrl":"https://doi.org/10.1021/acsnano.5c11799","url":null,"abstract":"Harnessing hot interlayer excitons (HIEs) in two-dimensional (2D) van der Waals (vdW) heterostructures offers a promising strategy for advancing hot-carrier optoelectronics beyond the Shockley–Queisser limit. However, the spatiotemporal diffusion dynamics and cooling behavior of HIEs remain poorly understood, particularly in transition metal dichalcogenide (TMD) bilayer heterostructures where moiré potentials significantly influence interlayer exciton transport. Here, we investigate a WSe2/WS2 bilayer heterostructure with a twist angle of ∼36°, a configuration that effectively suppresses moiré potential. We uncover a linear spatiotemporal diffusion behavior of interlayer excitons under weak moiré conditions─markedly different from the nonlinear dynamics typically observed in small-twist-angle systems (∼9°) dominated by strong moiré potentials. Furthermore, under above-bandgap excitation, we provide the direct experimental observation of the spatial diffusion of HIEs in a TMD bilayer heterostructure, a phenomenon that is difficult to observe in systems with strong moiré confinement. We demonstrate that the cooling time of HIEs is an order of magnitude longer than that of intralayer excitons in monolayer TMDs. This extended lifetime indicates the potential for efficient hot-carrier extraction in 2D heterostructures. Together, these findings offer insights into exciton transport and relaxation in moiré-engineered bilayer heterostructures and may inform the use of HIEs in optoelectronic and energy-harvesting applications.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"8 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145717403","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}
Nanoscale potential wells provide a powerful route to engineer energy landscapes in low-dimensional materials, enabling deterministic control over quantum states, carrier dynamics, and optoelectronic responses. Such confinement governs phenomena including charge localization, transport anisotropy, band structure modulation, and light-matter interaction strength. Achieving such precision, however, has been hindered by conventional lithography, which introduces disorder, contamination, or substrate damage. Here, we demonstrate a laser nanomanufacturing approach to fabricate clean, resist-free, and etchant-free dielectric nanochannels in hexagonal boron nitride (hBN), featuring sub-10 nm widths and atomically smooth boundaries with subnanometer roughness. These nanochannels serve as dielectric templates that define programmable energy landscapes for monolayer molybdenum diselenide (MoSe2), forming excitonic energy funnels that suppress scattering and dramatically extend exciton transport lengths. Exciton transport is transformed from isotropic submicron diffusion into directional superdiffusion with quasi-ballistic propagation exceeding 5 μm at room temperature. The smooth dielectric boundaries further enable precise control over exciton trajectories, allowing for programmable transport pathways. This dry, scalable, and substrate-compatible approach establishes a versatile platform for deterministic exciton engineering and for advancing integrated photonic and optoelectronic devices.
{"title":"Sub-10 nm Nanochannels Enable Directional Quasi-Ballistic Exciton Transport over 5 μm at Room Temperature","authors":"Xiao-Jie Wang, Jia-Wei Tan, Xiao-Ze Li, Hong-Hua Fang, Guan-Yao Huang, Yang-Yi Chen, Yuan Luo, Jia-Tai Huang, Gong Wang, Qi-Hua Xiong, Xavier Marie, Hong-Bo Sun","doi":"10.1021/acsnano.5c16048","DOIUrl":"https://doi.org/10.1021/acsnano.5c16048","url":null,"abstract":"Nanoscale potential wells provide a powerful route to engineer energy landscapes in low-dimensional materials, enabling deterministic control over quantum states, carrier dynamics, and optoelectronic responses. Such confinement governs phenomena including charge localization, transport anisotropy, band structure modulation, and light-matter interaction strength. Achieving such precision, however, has been hindered by conventional lithography, which introduces disorder, contamination, or substrate damage. Here, we demonstrate a laser nanomanufacturing approach to fabricate clean, resist-free, and etchant-free dielectric nanochannels in hexagonal boron nitride (hBN), featuring sub-10 nm widths and atomically smooth boundaries with subnanometer roughness. These nanochannels serve as dielectric templates that define programmable energy landscapes for monolayer molybdenum diselenide (MoSe<sub>2</sub>), forming excitonic energy funnels that suppress scattering and dramatically extend exciton transport lengths. Exciton transport is transformed from isotropic submicron diffusion into directional superdiffusion with quasi-ballistic propagation exceeding 5 μm at room temperature. The smooth dielectric boundaries further enable precise control over exciton trajectories, allowing for programmable transport pathways. This dry, scalable, and substrate-compatible approach establishes a versatile platform for deterministic exciton engineering and for advancing integrated photonic and optoelectronic devices.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"26 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145711466","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}
Reducing iridium (Ir) usage is essential for the commercial viability of proton exchange membrane water electrolysis (PEMWE), where the oxygen evolution reaction (OER) is a major performance and cost bottleneck. Conventional Ir nanoparticles (∼5 nm) suffer from low dispersion and limited surface utilization. Here, we report a catalyst architecture comprising ultrathin Ir nanosheets (Ir NS) supported on spherical TiO2 particles (Ir NS/TiO2). The ∼100 nm TiO2 particles effectively disperses 1-3 μm-wide, sub 2 nm-thick Ir nanosheets, ensuring full surface exposure and continuous electron transport, despite the intrinsically low conductivity of TiO2. The Ir NS/TiO2 catalyst exhibits enhanced OER activity and durability in both half-cell and PEMWE single-cell configurations. At an Ir loading of 0.7 mgIr cm-2, Ir NS/TiO2 achieves 3.6 A cm-2 at 1.8 V, significantly outperforming commercial Ir nanoparticles (Ir NP, 2.6 A cm-2). Long-term operation at 1.0 A cm-2 over 1000 h shows a low voltage decay rate of 0.095 mV h-1, compared to 0.414 mV h-1 for Ir NP. Moreover, Ir NS/TiO2 with an Ir loading amount of 0.5 mgIr cm-2 delivers comparable performance to Ir NP at 1.4 mgIr cm-2. These results present Ir NS/TiO2 as a highly efficient and durable OER catalyst, supporting its potential for cost-effective, scalable green hydrogen production.
减少铱（Ir）的使用对于质子交换膜电解（PEMWE）的商业可行性至关重要，其中析氧反应（OER）是主要的性能和成本瓶颈。传统的红外纳米颗粒（~ 5 nm）存在分散性低和表面利用率有限的问题。在这里，我们报道了一种催化剂结构，由球形TiO2颗粒（Ir NS/TiO2）支撑的超薄Ir纳米片（Ir NS/TiO2）组成。尽管TiO2本身的导电性较低，但在~ 100 nm的TiO2颗粒有效地分散了1-3 μm宽、亚2 nm厚的Ir纳米片，确保了充分的表面暴露和连续的电子传递。Ir NS/TiO2催化剂在半电池和PEMWE单电池结构下均表现出增强的OER活性和耐久性。在0.7 mir cm-2的负载下，Ir NS/TiO2在1.8 V下达到3.6 A cm-2，显著优于商业Ir纳米颗粒（Ir NP, 2.6 A cm-2）。长期在1.0 A cm-2下工作超过1000小时，显示出0.095 mV h-1的低电压衰减率，而Ir NP的衰减率为0.414 mV h-1。此外，Ir负载量为0.5 mgIr cm-2的Ir NS/TiO2的性能与1.4 mgIr cm-2的Ir NP相当。这些结果表明，Ir NS/TiO2是一种高效耐用的OER催化剂，支持其具有成本效益，可扩展的绿色制氢潜力。
{"title":"Ultrathin Iridium Nanosheets on Titanium Oxide for High-Efficiency and Durable Proton Exchange Membrane Water Electrolysis.","authors":"Dongwon Shin,Sang Jae Lee,Junu Bak,Jeonghan Roh,KwangHo Lee,HyunWoo Chang,Hyein Lee,MinJun Kim,HyunWoo J Yang,Seonghyun Kim,Seungbum Hong,EunAe Cho","doi":"10.1021/acsnano.5c15659","DOIUrl":"https://doi.org/10.1021/acsnano.5c15659","url":null,"abstract":"Reducing iridium (Ir) usage is essential for the commercial viability of proton exchange membrane water electrolysis (PEMWE), where the oxygen evolution reaction (OER) is a major performance and cost bottleneck. Conventional Ir nanoparticles (∼5 nm) suffer from low dispersion and limited surface utilization. Here, we report a catalyst architecture comprising ultrathin Ir nanosheets (Ir NS) supported on spherical TiO2 particles (Ir NS/TiO2). The ∼100 nm TiO2 particles effectively disperses 1-3 μm-wide, sub 2 nm-thick Ir nanosheets, ensuring full surface exposure and continuous electron transport, despite the intrinsically low conductivity of TiO2. The Ir NS/TiO2 catalyst exhibits enhanced OER activity and durability in both half-cell and PEMWE single-cell configurations. At an Ir loading of 0.7 mgIr cm-2, Ir NS/TiO2 achieves 3.6 A cm-2 at 1.8 V, significantly outperforming commercial Ir nanoparticles (Ir NP, 2.6 A cm-2). Long-term operation at 1.0 A cm-2 over 1000 h shows a low voltage decay rate of 0.095 mV h-1, compared to 0.414 mV h-1 for Ir NP. Moreover, Ir NS/TiO2 with an Ir loading amount of 0.5 mgIr cm-2 delivers comparable performance to Ir NP at 1.4 mgIr cm-2. These results present Ir NS/TiO2 as a highly efficient and durable OER catalyst, supporting its potential for cost-effective, scalable green hydrogen production.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"6 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145711007","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}
Copper-based antibacterial systems leverage reactive oxygen species (ROS) for effective pathogen control but are limited by issues such as cytotoxicity and resistance due to Cu ion release. By anchoring copper single-atom catalysts (Cu SACs) on biocompatible boron nitride (BN) nanosheets, we create a stable, high-efficiency antibacterial platform that minimizes Cu-ion-induced cytotoxicity and bacterial resistance. This configuration maximizes metal utilization and enhances photocatalytic efficiency for ROS generation, including hydroxyl radicals and superoxide anions. The defect-assisted covalent bonding between Cu and BN ensures stable coordination, preventing metal ion dissolution. First-principles quantum calculations at the level of density functional theory (DFT) provided critical insights into the structures and mechanisms of ROS generation, showing how atomic-level interactions between Cu and BN surfaces boost catalytic activity and clarified electron transfer processes and adsorption energies essential for ROS formation. These insights explain the observed catalytic behaviors and provide valuable design principles for developing efficient, low-toxicity SAC-based antibacterial systems. Additionally, we studied other elements in the same row (Cr, Mn, Fe, Co, Ni, and Zn) experimentally and theoretically. The d-BN-Cu system rapidly inactivated E. coli (106 CFU mL-1), achieving significant results with d-BN-Cu1 (Cu, 0.26 at. % with Cu nanoclusters) within 15 min, and d-BN-Cu3 (Cu, 0.024 at. % with Cu SAC) within 30 min when exposed to sunlight. Although higher copper content can achieve better antibacterial effects, it also brings other potential risks, such as metal ion leaching and higher cytotoxicity. This risk can be effectively avoided by utilizing SACs, as all of the Cu SACs are securely anchored at the defect sites in h-BN through covalent bonds. Cell toxicity testing and in vivo testing emphasize the unique advantages of d-BN-Cu3 (SAC) in balancing safety and efficiency. This SAC two-dimensional platform can not only effectively combat Gram-negative and Gram-positive bacteria but also effectively avoid the toxicity caused by the metal itself.
{"title":"Enhanced Antibacterial Efficacy of Copper Single-Atom Catalysts on a Two-Dimensional Boron Nitride Platform.","authors":"Wenbo Li,Daniel Maldonado-Lopez,Yingcan Zhao,Cong Wang,Jianxiang Gao,Bowen Sun,Yichao Bai,Linxuan Sun,Mingchuang Zhao,Haoqi He,Jiatao Lou,Qiangmin Yu,Xi Zhang,Vijay Kumar Pandey,Feiyu Kang,Mauricio Terrones,Jose L Mendoza-Cortes,Yu Lei","doi":"10.1021/acsnano.5c13145","DOIUrl":"https://doi.org/10.1021/acsnano.5c13145","url":null,"abstract":"Copper-based antibacterial systems leverage reactive oxygen species (ROS) for effective pathogen control but are limited by issues such as cytotoxicity and resistance due to Cu ion release. By anchoring copper single-atom catalysts (Cu SACs) on biocompatible boron nitride (BN) nanosheets, we create a stable, high-efficiency antibacterial platform that minimizes Cu-ion-induced cytotoxicity and bacterial resistance. This configuration maximizes metal utilization and enhances photocatalytic efficiency for ROS generation, including hydroxyl radicals and superoxide anions. The defect-assisted covalent bonding between Cu and BN ensures stable coordination, preventing metal ion dissolution. First-principles quantum calculations at the level of density functional theory (DFT) provided critical insights into the structures and mechanisms of ROS generation, showing how atomic-level interactions between Cu and BN surfaces boost catalytic activity and clarified electron transfer processes and adsorption energies essential for ROS formation. These insights explain the observed catalytic behaviors and provide valuable design principles for developing efficient, low-toxicity SAC-based antibacterial systems. Additionally, we studied other elements in the same row (Cr, Mn, Fe, Co, Ni, and Zn) experimentally and theoretically. The d-BN-Cu system rapidly inactivated E. coli (106 CFU mL-1), achieving significant results with d-BN-Cu1 (Cu, 0.26 at. % with Cu nanoclusters) within 15 min, and d-BN-Cu3 (Cu, 0.024 at. % with Cu SAC) within 30 min when exposed to sunlight. Although higher copper content can achieve better antibacterial effects, it also brings other potential risks, such as metal ion leaching and higher cytotoxicity. This risk can be effectively avoided by utilizing SACs, as all of the Cu SACs are securely anchored at the defect sites in h-BN through covalent bonds. Cell toxicity testing and in vivo testing emphasize the unique advantages of d-BN-Cu3 (SAC) in balancing safety and efficiency. This SAC two-dimensional platform can not only effectively combat Gram-negative and Gram-positive bacteria but also effectively avoid the toxicity caused by the metal itself.","PeriodicalId":21,"journal":{"name":"ACS Nano","volume":"240 1","pages":""},"PeriodicalIF":17.1,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145711006","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：