Nature Nanotechnology
Nature Nanotechnology provides a forum for the publication of top-quality research papers in all areas of nanoscience and nanotechnology. Coverage in Nature Nanotechnology extends from basic research in physics, chemistry and biology through to the development of new devices and technologies for applications in a wide range of industrial sectors. Organic, inorganic and hybrid materials are all covered.
In a gate defined quantum dot in Bernal bilayer graphene, a combination of spin and valley protection diminishes spin relaxation drastically and yields a lifetime of 38 seconds.
A transistor made from bilayer A-type antiferromagnet CrPS4 provides control over the spin polarization at the Fermi level and magnetoelectric readout.
An interface between microwave and optical photons offers the potential to network remote superconducting quantum processors. To preserve fragile quantum states, a microwave-to-optical transducer must operate efficiently in the quantum-enabled regime by generating less than one photon of noise referred to its input. Here we achieve these criteria using an integrated electro-optomechanical device made from crystalline silicon. Our platform eliminates the need for heterogeneous integration with piezoelectric materials by utilizing electrostatic actuation of gigahertz-frequency nanomechanical oscillators. Leveraging the ultra-low mechanical dissipation in silicon, our microwave-to-optical transducers achieve below one photon of input-referred added noise (nadd = 0.58) under continuous-wave laser drives. This demonstration of continuous quantum-enabled microwave-to-optical transduction improves the upconversion rate by about two orders of magnitude beyond the state of the art (R = 0.47–1.9 kHz). The increased transduction rate and scalable fabrication of our devices may facilitate near-term use of transducers in distributed quantum computers and quantum networks. Networking remote superconducting quantum computers requires low-noise microwave-to-optical photon conversion. A transducer based on an integrated silicon electro-optomechanical resonator now achieves below one photon of added noise referred to the transducer input while operating continuously under laser drive.
Antiferromagnetic conductors with suitably broken spatial symmetries host spin-polarized bands, which lead to transport phenomena commonly observed in metallic ferromagnets. In bulk materials, it is the given crystalline structure that determines whether symmetries are broken and spin-polarized bands are present. Here we show that, in the two-dimensional limit, an electric field can control the relevant symmetries. To this end, we fabricate a double-gate transistor based on bilayers of van der Waals antiferromagnetic semiconductor CrPS4 and show how a perpendicular electric displacement field can switch the spin polarization of the conduction band on and off. Because conduction band states with opposite spin polarizations are hosted in the different layers and are spatially separated, these devices also give control over the magnetization of the electrons that are accumulated electrostatically. Our experiments show that double-gated CrPS4 transistors provide a viable platform to create gate-induced conductors with near unity spin polarization at the Fermi level, as well as devices with a full electrostatic control of the total magnetization of the system. Double-gate transistors of bilayer layered antiferromagnet CrPS4 give full control of the spin polarization of the conduction band and of the magnetization of the accumulated electrons.
A non-flammable electrolyte formulation enables long-life and high-energy sodium-based batteries.
All-dielectric optical nano-resonators have emerged as low-loss, versatile and highly adaptable components in nanophotonic structures for manipulating electromagnetic waves and enhancing light–matter interactions. However, achieving full three-dimensional characterization of near fields within dielectric nano-resonators poses great experimental challenges. Here we develop a technique to image near-field wave patterns inside dielectric optical nano-resonators using high-order sideband generation. By exploiting the phase sensitivity of various harmonic orders, which enables the detection of near-field distributions at distinct depths, we achieve three-dimensional tomographic and near-field imaging with a transverse resolution of ~920 nm and a longitudinal resolution of ~130 nm inside a micrometre-thick silicon anapole resonator. Our method offers high-contrast polarization sensitivity and phase-resolving capabilities, providing comprehensive vectorial near-field information and could be applied to diverse dielectric metamaterials. The phase sensitivity of high harmonic modes enables the reconstruction of the three-dimensional near-field distribution inside a resonator.
Insulin crystals coated with a thin, porous membrane with electrical potential-sensitive channels — named i-crystal — show glucose- and ketone-responsive insulin release. Owing to their high drug-loading content and slow, zero-order insulin release kinetics, i-crystal can regulate the blood glucose level for more than 1 month in mice models with type 1 diabetes.
The nuclear envelope serves as a highly regulated gateway for macromolecule exchange between the nucleus and cytoplasm in eukaryotes. Here we have developed a cell nucleus-mimicking polymeric membrane-enclosed system for long and self-regulated therapy. A polymeric nano-membrane with nanopores is conformally synthesized in situ on the surface of each insulin crystal, ensuring sustained, adjustable and zero-order drug release kinetics. Glucose- and β-hydroxybutyrate-dually sensitive microdomains are integrated into the nano-membranes. Under a normal state, the microdomains are uncharged and the channel is narrow enough to block insulin outflow. Under hyperglycaemia and ketonaemia, microdomains convert the high glucose and β-hydroxybutyrate concentration signals to the negative electric potential of membranes, widening the nanopores with rapid insulin outflow. In type 1 diabetic mice and minipigs, this system can maintain normoglycaemia for longer than 1 month and 3 weeks, respectively, with validated glucose- and β-hydroxybutyrate-triggered insulin release. Such membrane-enclosed drug crystal/powder formulation provides a broad platform for long-acting controlled release. This article presents a polymeric membrane-enclosed insulin crystal equipped with physiological signal-sensing microdomains, dubbed ‘smart drug crystals’, that enables long-term, glucose- and β-hydroxybutyrate-dually responsive drug release for type 1 diabetes therapy.
Multiscale cation inhomogeneity has been a major hurdle in state-of-the-art formamidinium–caesium (FA–Cs) mixed-cation perovskites for achieving perovskite solar cells with optimal power conversion efficiencies and durability. Although the field has attempted to homogenize the overall distributions of FA–Cs in perovskite films from both plan and cross-sectional views, our understanding of grain-to-grain cation inhomogeneity and ability to tailor it—that is, spatially resolving the FA–Cs compositional difference between individual grains down to the nanoscale—are lacking. Here we reveal that as fundamental building blocks of a perovskite film, individual grains exhibit cationic compositions deviating from the prescribed ideal composition, severely limiting the interfacial optoelectronic properties and perovskite layer durability. This performance-limiting nanoscopic factor is linked to thermodynamic-driven morphological grooving, leading to a segmented surface landscape. At the grain triple junctions, grooves form nanoscale groove traps that hinder the mixing of solid-state cations across grains and thus retard inter-grain FA–Cs mixing. By rationally modulating the heterointerfacial energies, we reduced the depth of these nanoscale groove traps by a factor of three, significantly improving cation homogeneity. Perovskite solar cells with shallower nanoscale groove traps demonstrate enhanced power conversion efficiencies (25.62%) and improved stability under various standardized international protocols. Our work highlights the significance of resolving surface nano-morphologies for homogeneous properties of perovskites. Nano-groove traps at grain triple junctions significantly affect cation homogeneity in formamidinium–caesium perovskite films. Shallowing these traps improves interfacial properties and enhances solar cell performance.
Crossing the blood–brain barrier (BBB) and reaching intracranial tumours is a clinical challenge for current targeted interventions including antibody-based therapies, contributing to poor patient outcomes. Increased cell surface density of human epidermal growth factor receptor 3 (HER3) is associated with a growing number of metastatic tumour types and is observed on tumour cells that acquire resistance to a growing number of clinical targeted therapies. Here we describe the evaluation of HER3-homing nanobiological particles (nanobioparticles (NBPs)) on such tumours in preclinical models and our discovery that systemic NBPs could be found in the brain even in the absence of such tumours. Our subsequent studies described here show that HER3 is prominently associated with both mouse and human brain endothelium and with extravasation of systemic NBPs in mice and in human-derived BBB chips in contrast to non-targeted agents. In mice, systemically delivered NBPs carrying tumoricidal agents reduced the growth of intracranial triple-negative breast cancer cells, which also express HER3, with improved therapeutic profile compared to current therapies and compared to agents using traditional BBB transport routes. As HER3 associates with a growing number of metastatic tumours, the NBPs described here may offer targeted efficacy especially when such tumours localize to the brain. Delivering therapeutics to the brain is challenging because of the hard-to-cross blood–brain barrier. Here, the authors show that HER3, which is expressed on the surface of many metastatic tumours, is associated with the brain endothelium and can drive accumulation of HER3-targeted nanoparticles within the brain, for therapy against HER3-positive tumours.
The ordering of ions and solvent molecules around nanostructures is of profound fundamental importance, from understanding biological processes to the manipulation of nanomaterials to optimizing electrochemical devices. Classical models commonly used to describe these systems treat the solvent simplistically, an approach that endures, in part, due to the extreme difficulty of attaining experimental measurements that challenge this approximation. Here we perform total neutron scattering experiments on model systems—concentrated amide solutions of negatively charged carbon nanotubes and sodium counterions—and measure remarkably complex intermediate-range molecular solvent ordering. The charged surface orders the solvents up to ∼40 Å, even beyond its dense concentric solvation shells. Notably, the molecular orientation of solvent in direct contact with the nanotube surface itself is distinct, lying near-parallel and not interacting with desolvated sodium counterions. In contrast, beyond this layer the ordering of solvent is perpendicular to the surface. Our results underscore the critical importance of multibody interactions in solvated nanoscale systems and charged surfaces, highlighting competing ion/surface solvation effects. Neutron scattering on a model system of highly concentrated solutions of charged carbon nanotubes reveals a strong solvent ordering up to ∼40 Å around the charged nanoscale surface.
Theoretical studies discover quantum momentum tunnelling between liquid flows separated by nanometre-thick graphene layers via the interaction between molecular dipole excitations and plasmons.
Spin qubits in silicon are strong contenders for the realization of a practical quantum computer. Single- and two-qubit gates have shown fidelities above the fault-tolerant threshold, and entanglement of three qubits has been achieved. Furthermore, high-fidelity operation of two-qubit algorithms is possible. Here we implement a four-qubit silicon processor with all control fidelities above the fault-tolerant threshold. We demonstrate a three-qubit Grover’s search algorithm with a ~95% probability of finding the marked state. To this end, we fabricate the processor from three phosphorus atoms precision-patterned into isotopically pure silicon. We define three phosphorus nuclear spin qubits and one electron spin qubit. The long coherence times of the qubits enable single-qubit fidelities above 99.9% for all qubits. Moreover, the efficient single-pulse multi-qubit operation enabled by the electron–nuclear hyperfine interaction facilitates controlled-Z gates with above 99% fidelity between all pairs of nuclear spins when using the electron as an ancilla. These control fidelities, combined with high-fidelity non-demolition readout of all nuclear spins, allows the creation of a three-qubit Greenberger–Horne–Zeilinger state with 96.2% fidelity. Looking ahead, coupling neighbouring nuclear spin registers, as the one shown here, via electron–electron exchange may enable larger, yet fault-tolerant, quantum processors. A four-qubit processor of three phosphorus nuclear spins and an electron spin in silicon enables the implementation of a three-qubit Grover’s search algorithm with 95% fidelity. The implementation is based on an advanced multi-qubit gate with single-qubit gate fidelities above 99.9% and two-qubit gate fidelities above 99%.
Imbalanced redox homeostasis, involving either oxidative stress or reductive stress, can profoundly impact cellular functions, contributing to various diseases. While the implications of oxidative stress in the adverse effects of nanoparticles have been extensively studied, our comprehension of reductive stress within the context of nano-redox system interactions remains limited. Here we illuminate a domino effect initiated by the dehydrogenase-like activity of transition metal borides. Specifically, seven transition metal borides were identified to emulate the enzymatic activity of natural dehydrogenases, resulting in heightened levels of reductive constituents within critical biological redox pairs in cells. Mass cytometry analysis provides compelling evidence that reductive stress initiates an immunosuppressive environment within lung tissues, promoting the metastasis of breast cancer cells to the lungs. In summary, our study unveils the chemical basis of nano-induced reductive stress and establishes a mechanistic axis that interlinks dehydrogenase-like activity, reductive stress, immunosuppression and tumour metastasis. This paper shows that nano-enabled dehydrogenation catalysis in biological systems induces a domino effect, including reductive stress, immunosuppression and tumour metastasis.
How far away are lab-scale nanotechnologies from commercialization? We asked two journalists to investigate.
Cobalt phthalocyanine (CoPc) is recognized for catalysing electrochemical CO2 reduction into methanol at high Faradaic efficiency but is subject to deactivation. Cobalt tetraaminophthalocyanine (CoPc-NH2) shows improved stability, but its methanol Faradaic efficiency is below 30%. This study addresses these limitations in selectivity, reactivity and stability by rationally designing a dual-site cascade catalyst. Here we quantify the local concentration of CO, a key intermediate of the reaction, near a working CoPc-NH2 catalyst and show that co-loading nickel tetramethoxyphthalocyanine (NiPc-OCH3) with CoPc-NH2 on multiwalled carbon nanotubes increases the generation and local concentration of CO. This dual-site cascade catalyst exhibits substantially higher performance than the original single-site CoPc-NH2/carbon nanotube catalyst, reaching a partial current density of 150 mA cm−2 and a Faradaic efficiency of 50% for methanol production. Kinetic analysis and in situ sum-frequency generation vibrational spectroscopy attribute this notable performance improvement to molecular-scale CO spillover from NiPc-OCH3 sites to methanol-active CoPc-NH2 sites. A dual-site electrocatalyst is developed to greatly enhance methanol production from CO2 reduction via a cascade process, taking advantage of molecular-scale CO spillover.
Pyroptosis has emerged as a promising approach for cancer immunotherapy. However, current pyroptosis inducers lack specificity for cancer cells and have a weak antitumour immune response. Here we report a tumour-specific nanoparticle (NP-NH-D5) that activates pyroptosis by disrupting lysosomes for cancer immunotherapy. NP-NH-D5 undergoes negative-to-positive charge reversal and nanoparticle-to-nanofibre transformation within tumour cell lysosomes through tandem response to extracellular matrix metallopeptidase-2 and intracellular reducing agents. The as-formed non-peptide nanofibres efficiently break the lysosomes and trigger gasdermin-D-mediated pyroptosis, leading to strong immunogenic cell death and alleviation of the immunosuppressive tumour microenvironment. In vivo, NP-NH-D5 inhibits orthotopic 4T1 breast tumours, prevents metastasis and recurrence, and prolongs survival without systemic side effects. Furthermore, it greatly enhances the effectiveness of PD-L1 antibody immunotherapy in the 4T1 late-stage lung metastasis and aggressive orthotopic Pan02 pancreatic tumour models. Our research may open pathways for developing stimuli-responsive pyroptosis inducers for precise cancer immunotherapy. Controlled synthesis of supramolecular structures within lysosomes holds promise for cancer imaging and treatment. The authors introduce a programmable assembly strategy to generate fluorescent nanofibres in tumour cell lysosomes, enabling targeted tumour accumulation and inducing pyroptosis for precise cancer imaging and immunotherapy.
Relaxor ferroelectrics (relaxors) are a special class of ferroelectrics with polar nanodomains (PNDs), which present characteristics such as slim hysteresis loops and strong dielectric relaxation. Applications such as nanoelectromechanical systems, capacitive-energy storage and pyroelectric-energy harvesters require thin-film relaxors. Hence, understanding relaxor behaviour in the ultrathin limit is of both fundamental and technological importance. Here the evolution of relaxor phases and PNDs with thickness is explored in prototypical thin relaxor films. Epitaxial 0.68PbMg1/3Nb2/3O3-0.32PbTiO3 films of various nanometre thicknesses are grown by pulsed-laser deposition and characterized by ferroelectric and dielectric measurements, temperature-dependent synchrotron X-ray diffuse scattering, scanning transmission electron microscopy and molecular dynamics simulations. As the film thickness approaches the length of the long axis of the PNDs (25–30 nm), electrostatically driven phase instabilities induce their rotation towards the plane of the films, stabilize the relaxor behaviour and give rise to anisotropic phase evolution along the out-of-plane and in-plane directions. The complex anisotropic evolution of relaxor properties ends in a collapse of the relaxor behaviour when the film thickness reaches the smallest dimension of the PNDs (6–10 nm). These findings establish that PNDs define the critical length scale for the evolution of relaxor behaviour at the nanoscale. Geometrical confinement in ultrathin 0.68PbMg1/3Nb2/3O3-0.32PbTiO3 films induces a dome-shaped stability region of relaxor behaviour in a temperature–thickness relaxor phase diagram.
Two decades after the exfoliation of graphene, the focus is shifting to ‘reassembling’ graphite to uncover new insights into interacting electrons.
In vivo CRISPR gene editing holds enormous potential for various diseases. Ideally, CRISPR delivery should be cell type-specific and time-restricted for optimal efficacy and safety, but customizable methods are lacking. Here we develop a cell-tropism programmable CRISPR–Cas9 ribonucleoprotein delivery system (RIDE) based on virus-like particles. The efficiency of RIDE was comparable to that of adeno-associated virus and lentiviral vectors and higher than lipid nanoparticles. RIDE could be readily reprogrammed to target dendritic cells, T cells and neurons, and significantly ameliorated the disease symptoms in both ocular neovascular and Huntington’s disease models via cell-specific gene editing. In addition, RIDE could efficiently edit the huntingtin gene in patients’ induced pluripotent stem cell-derived neurons and was tolerated in non-human primates. This study is expected to facilitate the development of in vivo CRISPR therapeutics. This paper reports a customizable CRISPR ribonucleoprotein delivery tool, dubbed RIDE, for the treatment of Huntington’s disease in mice, non-human primates and patients’ iPSC neurons.
Rare earth elements (REEs), including scandium, yttrium and lanthanides, are strategic resources with unique electric, luminescent and magnetic properties. However, owing to their highly similar physiochemical properties, the identification and separation of all REEs are challenging. Here a Mycobacterium smegmatis porin A nanopore is engineered to contain a nitrilotriacetic acid ligand at its pore constriction. By the further introduction of a secondary ligand Nα,Nα-bis(carboxymethyl)-L-lysine hydrate (ANTA), a dual-ligand sensing strategy was established. A unique property of this strategy is that a variety of REE(III) ions report characteristic blockage features containing three-level transitions, which are critical in discriminating different REE(III)s. The nanopore events of REE(III)s also demonstrate a clear periodicity, suggesting the observation of the lanthanide contraction effect at a single-molecule regime. Assisted by machine learning, all 16 naturally occurring REE(III)s have been identified by the nanopore with high accuracy. This sensing strategy is further applied in analysing bastnaesite samples, suggesting its potential use in geological exploration. Here the authors show that Mycobacterium smegmatis porin A modified with nitrilotriacetic acid achieves direct and simultaneous discrimination of rare earth elements, suggesting the potential use of nanopore sensing in geological exploration.
The intrinsic valley degree of freedom makes bilayer graphene (BLG) a unique platform for semiconductor qubits. The single-carrier quantum dot (QD) ground state exhibits a twofold degeneracy, where the two states that constitute a Kramers pair have opposite spin and valley quantum numbers. Because of the valley-dependent Berry curvature, an out-of-plane magnetic field breaks the time-reversal symmetry of this ground state and a qubit can be encoded in the spin–valley subspace. The Kramers states are protected against known spin- and valley-mixing mechanisms because mixing requires a simultaneous change of the two quantum numbers. Here, we fabricate a tunable QD device in Bernal BLG and measure a spin–valley relaxation time for the Kramers states of 38 s at 30 mK, which is two orders of magnitude longer than the 0.4 s measured for purely spin-blocked states. We also show that the intrinsic Kane–Mele spin–orbit splitting enables a Kramers doublet single-shot readout even at zero magnetic field with a fidelity above 99%. If these long-lived Kramers states also possess long coherence times and can be effectively manipulated, electrostatically defined QDs in BLG may serve as long-lived semiconductor qubits, extending beyond the spin qubit paradigm. A tunable quantum dot device in Bernal bilayer graphene possesses a spin–valley relaxation time of 38 s at millikelvin temperatures.
A distinctive multivalent-effect immobilization strategy fundamentally stabilizes the structure of deep-blue reduced-dimensional perovskite emitters and enhances excitonic radiative recombination. Using this effect, the efficiency and stability bottlenecks of deep-blue perovskite LEDs are overcome.
Non-collinear antiferromagnets, such as Mn3Sn, stand out for their topological properties and potential in antiferromagnetic spintronics. This emerging field aims at harnessing ultrafast magnetization dynamics of antiferromagnets through spin torques. Here we report the time-resolved dynamics of Mn3Sn on a picosecond timescale, driven by an optically induced spin current pulse. Our results reveal that the magnetization of Mn3Sn tilts immediately after the spin current pulse and subsequently undergoes 70 GHz precession. This immediate tilting underscores the predominant role of damping-like torque stemming from spin current absorption by Mn3Sn. We also determine the spin coherence length of Mn3Sn to be approximately 15 nm. This value substantially exceeds that of ferromagnets, highlighting a distinct spin-dephasing process in non-collinear antiferromagnets. Our results hold promise for ultrafast applications of non-collinear antiferromagnets and enrich our understanding of their spin-transfer physics. An optically induced spin current pulse induces gigahertz magnetization dynamics in Mn3Sn with a spin coherence length of approximately 15 nm, which is longer than in ferromagnets.
Nucleic acid therapeutics are used for silencing, expressing or editing genes in vivo. However, their systemic stability and targeted delivery to bone marrow resident cells remains a challenge. In this study we present a nanotechnology platform based on natural lipoproteins, designed for delivering small interfering RNA (siRNA), antisense oligonucleotides and messenger RNA to myeloid cells and haematopoietic stem and progenitor cells in the bone marrow. We developed a prototype apolipoprotein nanoparticle (aNP) that stably incorporates siRNA into its core. We then created a comprehensive library of aNP formulations and extensively characterized their physicochemical properties and in vitro performance. From this library, we selected eight representative aNP-siRNA formulations and evaluated their ability to silence lysosomal-associated membrane protein 1 (Lamp1) expression in immune cell subsets in mice after intravenous administration. Using the most effective aNP identified from the screening process, we tested the platform’s potential for therapeutic gene silencing in a syngeneic murine tumour model. We also demonstrated the aNP platform’s suitability for splice-switching with antisense oligonucleotides and for protein production with messenger RNA by myeloid progenitor cells in the bone marrow. Our data indicate that the aNP platform holds translational potential for delivering various types of nucleic acid therapeutics to myeloid cells and their progenitors. In this study, the authors present optimization and efficacy testing of apolipoprotein-based lipid nanoparticles for delivering various nucleic acid therapeutics in vivo to immune cells and their progenitors in the bone marrow.
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