Nature nanotechnology最新文献

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.

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.

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 0.68PbMg_1/3Nb_2/3O₃-0.32PbTiO₃ 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.

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.

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.

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 N_α,N_α-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.