Direct observation of individual fluorescent emitters is essential for studying quantum materials, chemical reactions, and biological systems. However, current single-molecule tracking methods only focuses on the localizations of molecules, overlooking molecular configuration and orientation. In this work, we introduce a high-throughput polarized single-molecule localization microscopy that simultaneously resolves the locations and emission dipole orientations of single fluorescent emitters with nanometer precision. Using the interface between pristine hexagonal boron nitride (h-BN) and an organic solvent as a challenging platform, we capture over 10⁵ fluorescent events and reveal distinct molecular interaction dynamics at room temperature. The measured dipole orientations align with the three-fold (C₃) rotational symmetry of the h-BN lattice, and molecular dynamics in the liquid environment can be modulated electrochemically, suggesting a route for on-demand control of quantum emitters. We also find that lateral diffusion at the solid-liquid interface is far more dynamic than that of solid-state emitters. This simultaneous tracking of molecular conformation and photophysics advances the understanding of single-molecule interactions and enables real-time sensing through two-dimensional materials.

We report cross-validated measurements of the isotope effect on dielectric relaxation for four isotopologues of ice and water, including the 1-10^{5}  Hz region, in which only sporadic and inconsistent measurements were previously available. In ice, the relaxation rates exhibit an activated temperature dependence with an isotope-independent activation energy. Across 248-273 K, the H_{2}O-to-D_{2}O relaxation rate ratio remains constant at 2.0±0.1. This scaling agrees with Kramers' theory in the high-friction limit if the moving mass is the proton or deuteron, indicating that dielectric relaxation is governed by a classic proton transfer over an energy barrier rather than molecular reorientation.

The performance of transistors based on two-dimensional transition metal dichalcogenide semiconductors is restricted by the poor interface quality between two-dimensional materials and conventional three-dimensional contacts. Transition-metal-dichalcogenide-based metal–semiconductor heterostructures have been developed to enhance device performance, but finding fabrication techniques that combine high-quality growth with scalability and broad applicability remains a challenge. Here we show that a method that combines metal–organic chemical vapour deposition and sulfurization can be used to create patterned heterostructures of niobium disulfide and molybdenum disulfide at the wafer scale. The niobium disulfide–molybdenum disulfide heterostructures can be used as the active channel material of field-effect transistors and non-volatile memory devices. Compared with pristine molybdenum disulfide, the heterostructures exhibit up to nine times higher on current due to a reduced contact resistance, a maximum effective mobility of 77 cm2 V−1 s−1 and a 95.8% yield (of 144 field-effect transistors). Furthermore, our floating-gate field-effect transistors show a large programming window, precise and continuous conductance modulation, endurance over 60,000 programming pulses and an estimated retention time of around 19 years. Device simulation shows that the large programming window of the long-channel devices (around 14 V) can be maintained at scaled gate lengths below 100 nm with proper control oxide scaling. Patterned and scalable two-dimensional metal–semiconductor heterostructures formed between niobium disulfide and molybdenum disulfide can be created using an in situ sulfurization process and used to make field-effect transistors and non-volatile memory devices.

Nanopore sensing has shown great potential; however, one of its major challenges remains the fast and uneven translocation of analytes in free translocation nanopore measurements. We recently introduced Scanning Ion Conductance Spectroscopy (SICS), a technique that enables precise control of translocation speed by immobilizing the analyte on the surface and regulating the speed through controlled capillary movement. This methodology requires a unique preparation of the analyte over conventional free-translocation experiments, as the analyte is captured by and immobilized along a DNA carrier that is attached to a glass surface. This chapter describes the preparation of the essential components required for experiments, including the capillary, buffer, measurement system, and, most importantly, the preparation of DNA carriers that can be functionalized with aptamers.

Correlative nanoscale surface characterization benefits from simultaneously measuring electronic and structural properties in the same environment, a capability that is essential for modern-day materials science and semiconductor failure analysis. In-situ AFM-SEM measurements facilitated by self-sensing cantilevers offer great potential here; however, they are limited due to their inherent capacitive crosstalk. Here, we demonstrate for the first time the in-situ implementation of single-pass heterodyne Kelvin probe force microscopy inside a scanning electron microscope, using piezo-resistive cantilevers. We overcome the capacitive crosstalk prevalent in piezo-resistive cantilevers by demodulating excitation and detection to simultaneously map surface topography and contact potential difference for correlation with compositional analysis. We systematically compare different operational modes of this heterodyne technique, elucidating their spatial resolution, signal sensitivity, and signal-to-noise ratio. The integrated approach yields exceptional signal quality and reveals how electron beam scan parameters can directly influence surface potential contrast. We demonstrate this correlative analysis workflow on two-dimensional heterostructures and semiconductor circuits. This work establishes a robust and versatile correlative imaging mode for in-situ Kelvin force and topography imaging inside a scanning electron microscope for next-generation semiconductor device analysis and materials science.

Osmotic energy, also known as blue energy, is a promising renewable power source that can harness natural salinity gradients. Emerging nanofluidic systems realize direct conversion of this energy to electricity via the reversed electrodialysis process. However, achieving precise structural control, solid-liquid interface regulation and scalable demonstration for enhanced osmotic conversion in a nanofluidic system simultaneously remains a challenge. Here we develop a liquidized coating-functionalized nanofluidic system by combining scalable semiconductor microfabrication with a self-assembled lipid bilayer in nanoconfined environments. This hybrid platform enables precise structural control and interfacial regulation by coupling hydration lubrication with ultrahigh surface charge density. A numerical framework shows that the synergy between surface charge and slip length enhances ion transport and charge separation. Extending this strategy to a membrane-scale system (10(8) cm(-2) porosity, 314 mu m(2)) yields an osmotic power density of similar to 51.4 kW m(-2). This work outlines a promising framework for next-generation nanofluidic energy harvesting.

Abstract Biomolecular condensates are important regulators of cellular compartmentalization and biochemical processes. Understanding their material properties is critical to elucidate how they control molecular organization and dynamics within cells. However, quantitatively probing these properties remains challenging due to the wide range of length scales, concentrations, and timescales over which condensates operate, as well as the limited force ranges accessible to current nanoscale mechanical mapping methods. We explored the use of a non-contact 3D imaging tool Scanning Ion Conductance Microscopy (SICM) for stiffness measurements of liquid–liquid phase-separated biomolecular condensates. We focus on the Dhh1 protein, which is a regulator of cytoplasmic processing bodies (PBs) membrane-less cytoplasmic condensates that control the storage and degradation of untranslated mRNA. In our study, we investigate the properties of mCherry2- or His-mCherry2-tagged full-length Dhh1 and N- or C-terminus tail-deletion constructs, as well as the catalytically inactive mutant DQAD, under different pH and incubation times. We mapped both spatial and temporal changes in the material properties of the condensates, highlighting the capabilities of the instrument. We found that the removal of either of the two tails led to an increase in condensate stiffness upon shifting the pH from a stress-associated cellular environment (pH 6.5) to physiological conditions (pH 7.5). Additionally, the choice of protein tags led to vastly different results depending on the pH where mCherry2-Dhh1 exhibited a stiffening going from pH 6.0 to 6.5 while the double-tagged His-mCherry2 did not. Our measurements are verified and corroborated by established techniques such as optical tweezer-based fusion assays and fluorescence recovery after photobleaching (FRAP). Furthermore, we were able to track the same biomolecular condensate sample for up to 20 days getting insights on the ‘ageing’ and evolution of the condensates. Overall, our study demonstrates the applicability of SICM for direct measurement of the material properties of biomolecular condensate.

Abstract Water confined to channels one nanometer thick exhibits electrochemical behavior distinct from bulk water, including enhanced protonic conductivity and large dielectric anisotropy. Here, we exploit these characteristics to design a scalable electrochemical energy storage system-a “blue capacitor”-constructed entirely from naturally abundant materials. By assembling layered clays and conductive graphene, we produce 1-nm-thick channels in which confined water acts as the sole electrolyte. We systematically study different clay types, the electrode composition, and separator thickness using complementary physicochemical and electrochemical techniques. The device operates stably up to 1.6 ± 0.1 V, achieves specific capacitances of 40 F g−1, 97 ± 2% coulombic efficiency, and stable performance over more than 60,000 charge-discharge cycles at a voltage window of 1 V and a scan rate of 10 mA. Structural and dynamic analyses validate the device architecture, water purity, and proton transport in the nanopores. These results demonstrate that nanoconfined water can function as an electrolyte in a macroscopic electrochemical device, providing a platform for exploring sustainable aqueous energy storage systems.

β-barrel nanopores are involved in crucial biological processes, from ATP export in mitochondria to antibiotic resistance in Gram-negative bacteria, and represent a promising platform for emerging sequencing technologies. However, in contrast to ion channels, the understanding of the fundamental principles governing ion transport through these nanopores remains in its early stages. In this chapter, we describe the production and mutation of three major biological nanopores-aerolysin, MspA, and α-HL-as well as experimental approaches to elucidate ion transport mechanisms in these biological nanopores. Specifically, we provide tools to characterize two distinct nonlinear phenomena: open-pore rectification and gating, as well as guidelines to tune these phenomena to achieve a certain rectification or gating behavior.

Spin defects in two-dimensional materials hold significant potential for quantum information technologies and sensing applications. The negatively charged boron vacancy (VB-) in hexagonal boron nitride (hBN) has attracted considerable attention as a quantum sensor due to its demonstrated sensitivity to temperature, magnetic fields, and pressure.1 However, its applications have thus far been limited by inherently dim photoluminescence (PL). By fabricating a van der Waals heterostructure with a sensitizing donor layer, lead iodide (PbI2), we effectively enhance the PL intensity from the VB- by 5-45x, while maintaining compatibility with other heterostructures and vdW optoelectronic platforms. The type-I band alignment at the heterojunction enables efficient exciton migration while suppressing back-electron transfer, and the strong spectral overlap between the PbI2 emission and defect absorption supports efficient fluorescence resonance energy transfer. Ab initio density functional theory (DFT) predicts a photon-ratcheting mechanism that boosts absorption and emission while maintaining magnetic resonance (ODMR) contrast through minimal hybridization. Experimentally, the heterostructure exhibits enhanced continuous-wave ODMR sensitivity and functions as a precise probe of external magnetic fields. This work establishes a proof-of-concept for amplifying weak defect signals in nanomaterials, highlighting a new strategy for engineering their optical and magnetic responses.

These concluding remarks report on a Faraday Discussion in which angstrom-scale confinement emerged not as a geometric extension of bulk behaviour but as a qualitatively distinct thermodynamic and kinetic regime, with emerging evidence that some of its anomalies may have quantum origins. Opened by the Spiers Lecture of Prof. Lydéric Bocquet, the Discussion covered four sessions: structure and dynamics of confined molecules; stimuli-responsive transport; molecular and ion sieving; and iontronics and emergent neuromorphic effects. Machine-learning molecular dynamics at first-principles accuracy revealed a sharp three-layer structural transition in confined water and asymmetric solvation of OH- and H3O+ under hBN confinement. Active transport control has been demonstrated using light, strain, mechanical force, and solvent composition. Across these studies, surface chemistry and confinement consistently act together, emerging as the main determinants of ion selectivity. In iontronics, memristive-like behaviour has been reported across a remarkably broad range of mechanisms and an even wider variety of nanofluidic platforms, suggesting that such responses may be a pervasive feature of ionic systems whenever coupled transport, interfacial dynamics, and memory effects coexist. Reported origins include asymmetric ion-pair kinetics, energy-barrier rectification in funnel channels, confined water-dipole ordering, coupled capacitive-inductive memory effects, asymmetric electrochemical reactions, and other history-dependent ion-gating and interfacial processes. Across all sessions, a broad consensus emerged that progress on the most important open questions in water/ion transport will depend on close interplay between theory and experiment. At the same time, there was a strong sense that nanofluidics has reached a level of maturity that now makes these challenges tractable, reinforcing a broader excitement across the field.

Fluorescence super-resolution microscopy has advanced optical imaging into the nanoscale regime, transforming biological and interdisciplinary research. However, wide-field super-resolution techniques often compromise temporal resolution, thereby limiting the capture of rapid and transient biological events in living systems. Here we introduce spatial polarization-induced fluorescence fluctuation imaging (SPIFFI), a multichannel polarimetric method for single-shot super-resolution imaging and six-dimensional information extraction. By leveraging the inherently smaller point spread function under polarized detection and capturing polarization-dependent spatial fluctuations across multiplexed channels, SPIFFI achieves instant resolution enhancement from a single exposure. This capability substantially enhances the feasibility of volumetric live-cell super-resolution imaging. Moreover, SPIFFI images can integrate seamlessly with existing fluctuation-based methods for further postprocessing and resolution improvement. We demonstrate the versatility of SPIFFI through experiments on both fixed and live cells, capturing rapid subcellular dynamics and enabling high-throughput, multidimensional imaging beyond the diffraction limit. SPIFFI thus offers a practical and robust platform for real-time super-resolution imaging in biological research.

Fluorescence lifetime imaging microscopy (FLIM) is a powerful tool to discriminate fluorescent molecules or probe their nanoscale environment. Traditionally, FLIM uses time-correlated single-photon counting (TCSPC), which is precise but intrinsically low-throughput due to its dependence on point detectors. Although time-gated cameras have demonstrated the potential for high-throughput FLIM in bright samples with dense labeling, their use in single-molecule microscopy has not been explored extensively. Here, we report fast and accurate single-molecule FLIM with a commercial time-gated single-photon camera. Our optimized acquisition scheme achieves single-molecule lifetime measurements with a precision only about three times less than TCSPC, while imaging with a large number of pixels (512 × 512) allowing for the spatial multiplexing of over 3000 molecules. With this approach, we demonstrate parallelized lifetime measurements of large numbers of labeled pore-forming proteins on supported lipid bilayers, and temporal single-molecule Förster resonance energy transfer measurements at 5-25 Hz. This method holds considerable promise for the advancement of multi-target single-molecule localization microscopy and biopolymer sequencing.