Physics

Accurate monitoring of thermal dynamics at the single-cellular scale is crucial for elucidating metabolism, signaling pathways and disease mechanisms, yet remains hampered by the limited stability and spatiotemporal resolution of current sensors. Here, we report a fiber-optic quantum dots sensor (FOQDS), which is based on a tapered fiber optic tip functionalized with CdSe/CdS/ZnS QDs and encapsulated by a dense Al 2 O 3 layer to ensure exceptional long-term stability. FOQDS features a linear thermal response with high sensitivity (145 pm/°C), a temporal resolution of <10 μs, with the potential to achieve single-cellular-scale spatial precision. This performance enables quantitative and real-time monitoring of pharmacologically induced thermal fluctuations within living three-dimensional glioblastoma spheroids. This work provides a stable and minimally invasive platform for monitoring cellular thermogenesis in physiologically relevant microenvironments, with promising prospects in applications of fundamental biology and precision therapeutics.

Magnetic skyrmion bags, as high-order topological swirling spin textures, offer rich fundamental physics and distinct advantages for spintronic applications; however, their realization remains a formidable challenge, especially in two-dimensional (2D) systems. Here, through model analysis, we establish a theoretical framework for engineering skyrmion bags with tunable topology in symmetry-broken 2D ferromagnetic lattices. The physics correlates to the delicate interplay of isotropic exchange interaction, Dzyaloshinskii–Moriya interaction, and magnetic anisotropy, which can stabilize a rich variety of high-order topological spin states as well as the intriguing skyrmionium with zero topological charge. We further validate this mechanism in monolayer CrInTe 2 by using first-principles calculations and atomistic spin model simulations, revealing the existence of field-free skyrmion bags. Furthermore, we find that a weak magnetic field triggers a transition to skyrmioniums that maintains their structural integrity up to 240 K. Our results provide a compelling platform for exploring the high-order topological magnetism.

Polymer-derived ceramics (PDCs) are promising candidates for fabricating three-dimensional (3D) micro/nanodevices. However, their advancement has been constrained by a persistent challenge in that precursor simplicity, high-fidelity shaping of complex 3D architectures, and superior mechanical properties in the final ceramic are incompatible. To overcome this, an extremely simple photosensitive preceramic resin comprising only polycarbosilane and a photoinitiator is proposed to fabricate high-precision 3D PDC microstructures with intricate geometries and exceptional mechanical performance. A process involving prebaking and two-photon polymerization forms stable 3D preceramic polymer networks, which after pyrolysis yield defect-free amorphous SiOC ceramics exhibiting high shape fidelity and low linear shrinkage (28% at 1000 °C). The ceramics show temperature-dependent mechanical properties, with micropillar compressive strength reaching 6.41 GPa (1000 °C) and 7.55 GPa (1200 °C). Leveraging these properties, lightweight high-strength mechanical metamaterials with 20% relative density are fabricated, achieving a compressive strength of 0.54 GPa and a failure strain exceeding 10%. Functional microneedle arrays are also produced, highlighting their potential for biomedical applications. This work establishes a reliable and straightforward route from an extremely simple precursor to high-performance PDC micro/nano devices, showcasing promising prospects for applications in advanced microsystems and lightweight metamaterials.

Multidrug resistance (MDR) remains difficult to overcome because effective intracellular drug engagement is often reduced by limited drug availability and active efflux. Here, we develop a tandem enzyme-triggered self-assembly strategy to modulate these intracellular barriers with spatiotemporal control. A dual-enzyme-responsive precursor, pYFcFYp, is first dephosphorylated by extracellular alkaline phosphatase (ALP) and then oxidized by intracellular tyrosinase (Tyr), initiating covalent oligomerization and the formation of β-sheet-rich nanofibers. The staged assembly induces lysosomal membrane permeabilization (LMP) and cytosolic escape, accompanied by cytoskeletal remodeling and mitochondrial dysfunction, collectively contributing to G1/S-phase arrest and apoptosis. Importantly, LMP-associated doxorubicin redistribution was accompanied by increased intracellular retention and nuclear accumulation of doxorubicin; in parallel, decreased P-glycoprotein (P-gp/ABCB1) levels and a reduced drug-efflux phenotype were observed. These effects correlate with improved antitumor efficacy in vitro and in vivo . Overall, these results support tandem enzyme-guided intracellular self-assembly as a supramolecular route to chemosensitization.

High Resolution Image Download MS PowerPoint Slide Ferroelectric vortices, with their unique topological polarization patterns, show great potential for next-generation electronics. Although they have been observed in compounds, their realization in single-element materials has remained elusive. Here, we experimentally prepare three-bilayer Bi(110) square-shaped islands on high- T C superconductor (Bi 2 Sr 2 CaCu 2 O 8+δ ) substrates by molecular beam epitaxy. Scanning tunneling microscopy/spectroscopy combined with first-principles calculations suggests the possible existence of in-plane polarization and a ferroelectric vortex state in our islands, as well as reveals exceptional vortex stability against electric-field-driven switching. This work could pioneer single-element ferroelectric vortices, potentially advancing topological ferroelectrics design and expanding the understanding of related fundamental physics.

The nuclear pore complex (NPC) is a large protein assembly that controls transport of macromolecules to or from the nucleus in eukaryotic cells. It is capable of facilitated transport in which "cargo" species can bind to "shuttles", which specifically translocate the NPC, while the cargo alone cannot pass. In order to better understand the transport mechanism, attempts have been made to reconstruct the NPC transport using synthetic systems (bottom-up). However, it has proven difficult to achieve a functioning shuttle-cargo transport mechanism, in particular with high selectivity. Here, we present fully artificial NPCs based on heteromolecular polymer complexation. Polymer brushes consisting of poly(hydroxyethyl acrylamide) are prepared on solid-state nanopores to form a barrier that generally only allows small molecules (a few kg/mol) to pass. Still, at lowered pH, multivalent interactions with poly(methacrylic acid) enable efficient transport of this polymer through the brush barrier (predicted max rate >1000 molecules per pore per second). By fine-tuning the affinity, which is strongly dependent on factors such as pH and molecular weight, we show that the polymer shuttles can diffuse through the brush barrier without strongly altering its morphology. As a mimic of nucleic acid export through the NPC, we show that DNA cargo strands conjugated to the polymer shuttles translocate the pores, even though they are too large to pass in their free form. We consider the selectivity of our system to be exceptional, since there is no detectable leakage of unconjugated macromolecules, not even in the presence of free transport shuttles. Besides being of fundamental interest to understand soft matter in general and the NPC in particular, the possibility to switch transport on/off with pH enables unique applications of nanopore-based structures. As an example, we show secure, tether-free, and noninvasive trapping of molecules inside nanoscale chambers a few attoliters in volume under physiological conditions.

Plasmonic nanoparticles have generated great attention due to their potential applications in photocatalysis. The dissociation of hydrogen on Au nanoparticles has served as a useful model for this process, but despite many previous studies, there are important details of the dynamics which remain uncertain, such how single-photon absorption triggers dissociation. This paper addresses these issues through the study of gold clusters interacting with H 2, explicitly examining the effects of cluster size, shape, and excitation energy on the dissociation dynamics. By using time-dependent density functional theory (TDDFT) interfaced with trajectory surface hopping, we have examined the Au + H 2 system for states with excitation energies similar to the plasmon energy in gold. Three distinct outcomes are observed: H–H bond dissociation, H 2 desorption, and nonreactive relaxation. Trajectories starting in excited states of the cluster relax through extensive nonadiabatic surface hopping to lower excited states that couple to antibonding states where repulsion drives dissociation. In addition, hopping converts metal excitation to increased kinetic energy in H–H stretching that helps overcome dissociation barriers on reactive adiabats. This provides a detailed picture of the evolution of hot carriers into antibonding states of physisorbed molecules after extensive surface hopping that dissociate in ∼100 fs. Desorption and nonreactive relaxation compete with this picture. Our findings provide insights to photoinduced processes involving plasmonic nanoparticles showing how nonadiabatic dynamics plays a crucial role in accessing repulsive states while also releasing kinetic energy that drives dissociation.

We demonstrate a tailorable topological multimode nanolaser that supports simultaneous lasing in modes belonging to different topological classes and exhibiting no mutual phase correlation. Arrays of gold nanoparticles (NPs) with varying diameters were fabricated and embedded in a fluorescent dye gain medium, enabling the systematic investigation of the emergence and interplay between topologically trivial dipolar and topologically nontrivial quasi-bound-state-in-the-continuum (qBIC) modes. Angle- and wavelength-resolved measurements reveal single- and dual-mode lasing behavior, with far-field emission patterns and threshold characteristics strongly dependent on nanoparticle size. Spatial and temporal coherence characterization using interferometry shows mode-dependent coherence distributions across both the source plane and the far-field. We show that the relative contributions of the lasing modes can be tuned by adjusting the nanoparticle geometry, providing insights into the interplay between topologically distinct photonic modes and coherent light emission. Cross-correlation frequency-resolved optical gating measurements further resolve the temporal dynamics of the topologically trivial and qBIC modes, showing that these modes, having orthogonal polarizations at the sample plane, are mutually incoherent. This is in stark contrast to our previous results on topologically trivial superlattice modes, where shared excited-state molecular populations led to mode locking. The absence of mutual phase correlations is advantageous for applications requiring minimal crosstalk between lasing channels, such as multiplexed communication and multichannel sensing.

Epi-immunotherapy holds substantial potential in overcoming intrinsic and acquired resistance in tumor immunotherapy. However, most epi-immunotherapy strategies fail to match the dynamics of immune responses due to a lack of temporal regulation, resulting in short-lived efficacy. In addition, the instability and inefficient intracellular delivery of gene regulatory drugs, especially siRNA, further limit the therapeutic efficacy of epi-immunotherapy. Here, we propose and implement a temporal immunomodulation via methylation epigenetics (TIME) strategy through the combined intravenous administration of the FDA-approved small-molecule drug azacitidine and a BP/siPRMT1 nanocomplex. Azacitidine serves as the "Ignite" module, while BP/siPRMT1 was prepared by simple mixing of chemically synthesized boronated polypeptide (BP) with siPRMT1 at room temperature and functions as the "Sustain" module. By rapidly reducing intratumoral methylation levels through azacitidine, the expression of major histocompatibility complex class I (MHC-I) and secretion of interferon gamma (IFN-γ) were significantly enhanced, thereby igniting a hot tumor microenvironment. Subsequently, BP/siPRMT1 maintained high levels of MHC-I expression and IFN-γ secretion, sustaining the azacitidine-ignited antitumor immunity. Notably, the TIME strategy increased the proportion of MHC-I-positive tumor cells by 6.7-fold in tumor tissues. This "Ignite-Sustain" feature enables rapid immune sensitization and long-term immune maintenance. Compared to the delivery of an epi-drug or nucleic acid drug alone, the TIME strategy effectively expands the critical time window for immune activation, achieving durable and controllable tumor immunotherapy.

Neutrophils are an ideal drug carrier because of their specific targeting and effective accumulation at sites of inflammation. However, the clinical application of neutrophils as drug carriers is constrained by the inability to sustain ex vivo culture and their short lifespan. Herein, we developed an in situ construction strategy to fabricate neutrophil-nanoparticle biohybrid systems (NE@NPs) in vivo by specifically hijacking the pro-inflammatory neutrophils in blood using thermoresponsive drug-loaded NPs. The pro-inflammatory neutrophils effectively transport these NPs to the tumor microenvironment across the vascular barriers, followed by the release of the NPs through neutrophil extracellular traps (NETs). Subsequent near-infrared (NIR) light-induced spatiotemporally drug-controlled release improved the therapeutic response. The therapeutic efficacy of in situ-constructed NE@NPs is successfully confirmed using multiple mouse models of cancer, pulmonary, and skin infections. This study illustrates that the in situ construction strategy of neutrophil-NP hybrid systems in vivo may be a promising approach for improving inflammation-associated disease treatment.

Minimally invasive brain modulation is essential for understanding and treating neurological disorders. This study presents a wireless, optically controlled nitric oxide (NO)-releasing microbioelectronic device (ONMD) that enables peripheral-to-central neuromodulation without direct brain intervention. Upon light activation, the ONMD releases NO to locally activate transient receptor potential (TRP) channels, forming a confined NO-TRP signaling hub that selectively stimulates the vagus nerve and activates the nucleus tractus solitarius (NTS), a key brainstem center involved in autonomic and reward regulation. Through this hierarchical pathway, the ONMD-mediated neuromodulation alleviates depressive-like behaviors in mice, accompanied by reduced peripheral inflammation and restored central serotonin (5-HT) homeostasis. Operating in the intestine, the ONMD achieves remote modulation of central circuits through peripheral access. This gasotransmitter-mediated, multilevel bioelectronic approach offers a noninvasive strategy for regulating brain function and advancing neuropsychiatric therapies.

Photobatteries (PBs), which integrate photoactive materials into conventional battery architectures, offer an effective strategy to enhance battery performance by utilizing photogenerated charge carriers in the energy storage medium. Herein, we report scalable synthesis of WO 3– x -WS 2 nanosheet (NS)-based heterostructures for photoelectrodes in Li-ion PBs. These NS heterostructures enable broadband light harvesting (300–800 nm) and efficient separation of photocharge carriers. Atomically interfaced heterostructures of WO 3– x -WS 2 NSs have demonstrated stable electrochemical performance, retaining 80% of their capacity after 300 cycles with a specific capacity of 515.94 mAh g –1 (100–1000 mA g –1 ). Additionally, PBs exhibited enhanced kinetics under illumination (∼12 mW cm –2 ), resulting in a 35–59% increase in specific capacity. The dual-mesh current collector approach has been employed to increase the active mass loading, which further enhanced light–matter interaction and ultimately increased specific capacity. This work demonstrates a design framework for optimizing charge-carrier dynamics in PBs and establishes a viable pathway toward high-performance PBs for IoT applications.

Thiolate-protected gold (Au) nanoclusters (NCs) are a well-established class of model NCs that have been extensively studied as catalysts for various reactions. However, many Au NCs feature surfaces completely passivated by ligands, leaving no exposed metal sites to serve as active centers. To address this issue, researchers have searched for methods to remove the ligands. However, simply introducing weakly bound ligands often compromises the structural stability of the NCs. In this study, we identified a novel Au NC that remains stable even with relatively weakly bound thiolate ligands by reinforcing the staple motifs through the introduction of dithiolate ligands. This Au NC exhibits excellent CO oxidation activity at relatively low temperatures, because the ligands can dissociate under relatively mild conditions. These findings show that advanced ligand engineering, beyond the metal core structure, significantly affects catalytic activity, providing a robust strategy for the design of diverse metal NC catalysts.

As a cost-effective and acid-stable alternative to noble-metal catalysts, the rational design of high-performance metal-free electrocatalysts hinges on in-depth mechanistic insights and precise structural regulation. Graphene and its derivatives hold great promise, yet their heteroatom doping often compromises lattice integrity and intrinsic electronic properties. Herein, we report highly active HER electrocatalysts with ceramic-protected graphene edges that enable N 2 plasma functionalization while largely preserving the graphitic framework. Using in situ electrochemical characterization, we systematically investigate the catalytic role of nitrogen species in a ceramic-protected graphene edge architecture. The optimized catalyst delivers an overpotential of 46 mV at 10 mA cm –2, 6-fold lower than that of pristine edges even after 2000 CV cycles, outperforming most reported metal-free catalysts and approaching state-of-the-art metal-based benchmarks. Most importantly, these results propose a plausible protonation-gated mechanism: under acidic HER conditions, reversible protonation/deprotonation near-edge pyridinic N may tune α-C sites for favorable H adsorption, enhancing HER activity.

High Resolution Image Download MS PowerPoint Slide Pd nanoparticles are used in a variety of applications, and thus techniques that enable their high-throughput, label-free detection, as well as in situ reaction monitoring at catalytically relevant sizes, are needed to establish robust structure–function relationships. Here, we introduce wavelength-resolved interferometric scattering (iSCAT) as a strategy for performing these studies, over a range of Pd nanoparticle sizes. From a sample of ∼90 nm Pd octahedra we spectroscopically discriminate structural outliers based on their scattering resonances and spectral lineshapes, using simulations to validate the structure–spectral relationships. We then demonstrate direct detection of single Pd nanocubes with <20 nm edge length and track changes occurring to them in different reactive conditions, uncovering both interparticle heterogeneity and wavelength-dependent photochemistry. The results highlight the power of wavelength-resolved iSCAT for studying Pd nanoparticle transformations in situ and offer new insights into Pd reactivity at the nanoscale.

In thin layers of the 2D magnetic semiconductor CrSBr, very recent studies identified two distinct band-edge optical resonances, believed to arise from distinguishable bulk and surface excitons. This behavior reportedly originates from the highly anisotropic nature of CrSBr─particularly in its antiferromagnetic state─where excitons are effectively confined within individual monolayers, such that excitons in the two surface layers "see" a different local dielectric environment and have a lower resonance energy. To explore this scenario, here we investigate optical absorption properties of few-layer CrSBr in magnetic fields. In addition to the fundamental exciton resonance at ∼1.36 eV, we observe an absorption resonance ∼20 meV lower in energy. Compared to the fundamental transition, this resonance redshifts only half as much in small magnetic fields that induce ferromagnetic order, while in high fields to 55 T it exhibits a smaller diamagnetic shift. Both behaviors point to distinguishable populations of bulk and surface excitons in CrSBr.

The clinical application of nucleic acid aptamers is hindered by rapid degradation and poor targeting in physiological conditions. Multivalent assembly can improve their performance, yet key structural rules for stability are not fully clarified. Here, we fabricate a symmetric tetravalent aptamer-streptavidin conjugate (Tetra-XQ@SA) for cancer theranostics with greatly enhanced stability. Thymine bases, longer sequences, and double-stranded structures collectively strengthen its nuclease resistance, enabling stable storage for 96 h in DNase I and 72 h in serum. Compared with free aptamers, Tetra-XQ@SA shows 2-fold higher binding affinity to cancer cell CD71 receptors, 7-fold greater doxorubicin loading, and improved antitumor activity. It achieves prolonged tumor retention and an ∼73% tumor inhibition rate in vivo. This study reveals the structure-stability relationship of aptamer assemblies and offers a versatile platform for targeted cancer therapy.

High-entropy alloy (HEA) nanomaterials have emerged as promising electrocatalysts because of their compositional diversity and unique synergistic effects. Engineering the structure of HEAs, including facets, morphology, dimensions, and crystal phases, offers an effective strategy to further enhance their electrocatalytic performance. Such structural control provides a useful platform for unveiling the structure-performance relationships. This mini-review highlights recent advances in structural engineering of HEAs for electrocatalytic applications, with an emphasis on the structure formation mechanisms and structure-dependent catalytic performance. We first summarize representative synthetic strategies and discuss their advantages and limitations in the construction of well-defined HEA nanostructures. Then, we highlight the synthetic mechanisms of various HEA nanostructures and the functionalities of their unique structural characteristics in enhancing electrocatalysis. The structure-dependent performance of various HEA nanostructures in electrocatalytic reactions is reviewed from the perspectives of activity, selectivity, and durability. Finally, we discuss the current challenges and future opportunities for rationally designing next-generation HEA electrocatalysts.

ABSTRACT Formamidinium–cesium (FACs) perovskite is thermally stable, but the rapid crystallization process generates bulk defects and residual strains. We introduce a multifunctional additive, 3‐(Trifluoromethyl)aniline hydrochloride (3TFACl), to effectively regulate the crystallization process to improve stability and scalability of perovskite solar cells (PSCs) through multiple interactions with perovskite components. Crystallization‐defect‐strain engineering is synergistically integrated during film deposition. The champion power conversion efficiency (PCE) of p–i–n PSCs and 12 cm 2 module reach 26.76% (certified 26.12%) and 22.77%, respectively. The unencapsulated devices still maintain more than 94.36% of the initial efficiency after 1500 h maximum power point tracking (MPPT) (ISOS‐L‐1I protocol) and 80.5% initial efficiency after 1000 h under 85°C (ISOS‐D‐2I protocol). This work proposes a molecular design strategy with a simple structure but high synergy to achieve efficient, stable, and scalable perovskite photovoltaic devices.

ABSTRACT Self‐powered photoelectrochemical photodetectors are promising for sustainable underwater optoelectronics. However, severe charge recombination under zero bias hinders their ultraweak light (&lt;0.05 mW/cm 2 ) detection in marine environments. While oxygen vacancy (V O ) gradients improve carrier direction by deepening band bending to synergize with junction‐built‐in fields, existing studies focus on homogeneous gradient V O , causing chaotic lateral diffusion and non‐negligible recombination. Here, we propose a bio‐inspired “seeds‐taking‐root” strategy to construct localized V O gradients within 3D nanocoral‐like BiVO 4 . Through one‐step sintering, Ni seeds selectively extract O from BiVO 4 via strong Ni‐O interactions, simultaneously forming NiO x nanoclusters and NiO x ‐anchored localized gradient V O , leading to confined charge transfer pathways with localized space charge regions and unidirectional band bending for highly directional hole extraction. The structure achieves 82.5% charge separation efficiency at 1.23 V RHE (1.7 times than pristine BiVO 4 ), enabling efficient self‐powered broadband operation (365–940 nm). Even at 0.02 mW/cm 2 (matching real underwater light levels) in artificial seawater, it achieves a photoresponsivity of 43.82 ± 0.52 mA/W. It exhibits robust stability with over 50 h continuous operation and 98.5% photocurrent retention after one week in seawater. This seed‐mediated strategy for constructing directional charge transport channels offers a viable pathway for high‐performance optoelectronics in energy‐limited environments.