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Electron-transfer-mediated photoacid generation at 193 nm shows nonreciprocity and illustrates a possible pathway for two-photon acid generation. [ABSTRACT FROM AUTHOR]

Perpendicular nanochannel creation of two-dimensional (2D) nanostructures requires highly controlled anisotropic drilling processes of the entire structure via void formation. However, chemical approaches for the creation of porosity and defects of 2D nanostructures have been challenging due to the strong basal plane chemical stability and the use of harsh reactants, tending to give randomly corroded 2D structures. In this study, we introduce Lewis acid-base conjugates (LABCs) as molecular drillers with attenuated chemical reactivity which results in the well-defined perpendicular nanochannel formation of 2D TiS 2 nanoplates. With the treatment of LABCs, tris(trimethylsilyl)pnictogens (TMS 3 P or TMS 3 As), high resolution perforation of TiS 2 nanoplates was achieved while maintaining their initial shape and structures. Such perforated TiS 2 nanoplates are tunable in their channel diameter between 4 and 10 nm with 2 nm resolution. With their increased surface area and enhanced adsorption of Li 2 S x , perforated TiS 2 nanoplates served as a diffusion barrier of lithium-sulfur (Li-S) cells, leading to a 2.5-fold improvement in cell performance compared to pristine TiS 2 nanoplates. Our molecular design concept for attenuated reactivity of LABCs is simple and could serve as a new approach for chemical drilling processes of 2D metal chalcogenides.

In this study, we investigate the origins of low-frequency noise (LFN) and 1/ f noise in Cu 2 O thin-film transistors (TFTs). The static direct current (DC) I - V characterization demonstrates that the channel resistance ( R ch ) contributes significantly to mobility degradation in the TFTs, with channel thickness ( t ch ) controlled through the plasma-enhanced atomic layer deposition (PEALD) process. The 1/ f noise followed the Hooge mobility fluctuation (HMF) model, and it was observed that both Coulomb and phonon scattering within the channel, which increased with a decrease in t ch , contributed simultaneously. Increased R ch contributed more significantly to the 1/ f noise than to the contact resistance ( R C ), as evidenced by the R C configuration of the measurements, which also revealed that R C depends upon t ch . This study demonstrates that t ch is a major noise source in Cu 2 O TFTs and presents guidelines for the development of Cu 2 O TFTs and potential high-mobility p-type oxide semiconductors.

Treating type 1 diabetes (T1D) through β-cell macroencapsulation is a promising long-term solution, but it faces challenges such as immune-mediated fibrosis on the capsule surface, which impairs cell functionality and compromises longevity and effectiveness. This study presents an approach for including an anti-inflammatory molecule on the macroencapsulation device (MED) using initiated chemical vapor deposition for the surface modification of poly(tetrafluoroethylene) (PTFE) membranes. The surface-modified MEDs significantly reduced fibrosis, improved β-cell viability and functionality, and promoted M2 macrophage polarization, which is associated with anti-inflammatory effects. This MED displayed improved glycemic control in a streptozotocin-induced diabetic mouse model for 45 days. The findings underscore the potential of surface-modified MEDs for improving T1D management by mitigating inflammation and enhancing the therapeutic efficacy of β-cell encapsulation.

Molecular-profiling-based cancer diagnosis has significant implications for predicting disease prognosis and selecting targeted therapeutic interventions. The analysis of cancer-derived extracellular vesicles (EVs) provides a noninvasive and sequential method to assess the molecular landscape of cancer. Here, we developed an all-in-one fusogenic nanoreactor (FNR) encapsulating DNA-fueled molecular machines (DMMs) for the rapid and direct detection of EV-associated microRNAs (EV miRNAs) in a single step. This platform was strategically designed to interact selectively with EVs and induce membrane fusion under a specific trigger. After fusion, the DMMs recognized the target miRNA and initiated nonenzymatic signal amplification within a well-defined reaction volume, thus producing an amplified fluorescent signal within 30 min. We used the FNRs to analyze the unique expression levels of three EV miRNAs in various biofluids, including cell culture, urine, and plasma, and obtained an accuracy of 86.7% in the classification of three major breast cancer (BC) cell lines and a diagnostic accuracy of 86.4% in the distinction between patients with cancer and healthy donors. Notably, a linear discriminant analysis revealed that increasing the number of miRNAs from one to three improved the accuracy of BC patient discrimination from 78.8 to 95.4%. Therefore, this all-in-one diagnostic platform performs nondestructive EV processing and signal amplification in one step, providing a straightforward, accurate, and effective individual EV miRNA analysis strategy for personalized BC treatment.

While the molten salt-catalyzed chemical vapor deposition (CVD) technique is recognized for its effectiveness in producing large-area transition metal chalcogenides, understanding their growth mechanisms involving alkali metals remains a challenge. Here, we investigate the kinetics and mechanism of sodium-catalyzed molybdenum disulfide (MoS 2 ) growth and etching through image analysis conducted using an integrated CVD microscope. Sodium droplets, agglomerated via the thermal decomposition of the sodium cholate dispersant, catalyze the precipitation of supersaturated MoS 2 laminates and induce growth despite fragmentation during this process. Triangular MoS 2 crystals display a distinct self-exhausting exponential behavior and slow growth of thermodynamically favorable crystallographic faces, exhibiting a sulfur-dominant pressure. The growth and etching processes are facilitated by the scooting of sodium droplets along grain edges, displaying comparable rates. Leveraging these kinetics makes it possible to engineer atypical MoS 2 shapes. This combined microscope not only enhances the understanding of growth mechanisms but also contributes to the facile development of next-generation nanomaterials.

Colloidal PbS quantum dot solar cells (QDSCs) have been primarily demonstrated in n-i-p structures by incorporating a solution-processed ZnO electron transporting layer (ETL). Nevertheless, the inherent energy barrier for the electron extraction at the ZnO/PbS junction along with the defective nature significantly diminishes the performance of the PbS QDSCs. In this study, by employing Sn-doped ZnO (ZTO) ETL, we have tuned the conduction band offset at the junction from spike-type to cliff-type so that the electron extraction barrier can be eliminated and the overall photovoltaic parameters can be enhanced (open-circuit voltage of 0.7 V, fill factor over 70%, and efficiency of 11.3%) as compared with the counterpart with the undoped ZnO ETL. The X-ray photoelectron spectroscopy (XPS) analysis revealed a mitigation of oxygen vacancies in the ZTO ETL of our PbS QDSCs. Our work signifies the importance of Sn doping into the conventional ZnO ETL for the superior electron extraction in PbS QDSCs.

Frequent blood glucose monitoring is a crucial routine for diabetic patients. Traditional invasive methods can cause discomfort and pain and even pose a risk of infection. As a result, researchers have been exploring noninvasive techniques. However, a limited number of products have been developed for the market due to their high cost. In this study, we developed a low-cost, highly accessible, and noninvasive contact lens-based glucose monitoring system. We functionalized the surface of the contact lens with boronic acid, which has a strong but reversible binding affinity to glucose. To achieve facile conjugation of boronic acid, we utilized a functional coating layer called poly(tannic acid). The functionalized contact lens binds to glucose in body fluids (e.g., tear) and releases it when soaked in an enzymatic cocktail, allowing for the glucose level to be quantified through a colorimetric assay. Importantly, the transparency and oxygen permeability of the contact lens, which are crucial for practical use, were maintained after functionalization, and the lenses showed high biocompatibility. Based on the analysis of colorimetric data generated by the smartphone application and ultraviolet-visible (UV-vis) spectra, we believe that this contact lens has a high potential to be used as a smart diagnostic tool for monitoring and managing blood glucose levels.

In Li metal batteries (LMBs), which boast the highest theoretical capacity, the chemical structure of the solid electrolyte interphase (SEI) serves as the key component that governs the growth of reactive Li. Various types of additives have been developed for electrolyte optimization, representing one of the most effective strategies to enhance the SEI properties for stable Li plating. However, as advanced electrolyte systems become more chemically complicated, the use of additives is empirically optimized. Indeed, their role in SEI formation and the resulting cycle life of LMBs are not well-understood. In this study, we employed cryogenic transmission electron microscopy combined with Raman spectroscopy, theoretical studies including molecular dynamics (MD) simulations and density functional theory (DFT) calculations, and electrochemical measurements to explore the nanoscale architecture of SEI modified by the most representative additives, lithium nitrate (LiNO 3 ) and vinylene carbonate (VC), applied in a localized high-concentration electrolyte. We found that LiNO 3 and VC play distinct roles in forming the SEI, governing the solvation structure, and influencing the kinetics of electrochemical reduction. Their collaboration leads to the desired SEI, ensuring prolonged cycle performance for LMBs. Moreover, we propose mechanisms for different Li growth and cycling behaviors that are determined by the physicochemical properties of SEI, such as uniformity, elasticity, and ionic conductivity. Our findings provide critical insights into the appropriate use of additives, particularly regarding their chemical compatibility.

Recently, C 60 has emerged as a promising anode material for Li-ion batteries, attracting significant interest due to its excellent lithium storage capacity. The electrochemical performance of C 60 as an anode is largely dependent on its internal crystal structure, which is significantly influenced by the synthesis method and corresponding conditions. However, there have been few reports on how the synthesis process affects the crystal structure and Li + storage capacity of C 60 . This study used the liquid-liquid interface precipitation method and a low-temperature annealing process to fabricate one-dimensional C 60 nanorods (NRs). We thoroughly investigated synthesis conditions, including the growth time, drying temperature, annealing time, and annealing atmosphere. The results demonstrate that these synthesis conditions directly impact the morphology, phase transition, and electrochemical efficiency of pure C 60 NRs. Remarkably, the hexagonal close-packed structural C 60 NRs-6012h, in a metastable form, exhibits a reversible Li + storage capacity as an anode material in Li-ion batteries. Furthermore, the face-centered cubic C 60 NRs-603001h electrode shows significantly enhanced rate performance and long-cycle stability. A discharge-specific capacity of 603 mAh g -1 was maintained after 2000 cycles at a current density of 2 A g -1 . This study elucidates the effect of synthesis conditions on C 60 crystals, offering an effective strategy for preparing high-performance C 60 anode materials.

This study entailed the synthesis of Ru nanocatalyst decorated on Nb-grafted SBA-15. A Nb-grafted SBA-15 support with varying Nb contents was utilized as a support for the Ru nanoparticles. The effect of Nb grafting on the immobilized Ru nanoparticle catalyst was systematically investigated, and its catalytic performance in the synthesis of furandicarboxylic acid using 5-hydroxymethylfurfural under base-free reaction conditions was evaluated. The results indicate the increased productivity of the Ru@Nb-grafted SBA-15 catalyst with a yield exceeding 95%, representing a significant advancement in catalysis. This study also affords insights into the complex relationship between the catalytic activity and selectivity and its unique surface attributes. Moreover, acidic sites were created, and the electron density within the active sites was modulated by monomeric Nb oxide species on the SBA-15. Additionally, the role of high-electron-density Ru atoms in facilitating the efficient adsorption and activation of the reactant, resulting in enhanced catalytic efficacy, was highlighted.

Understanding the spatial organization of membrane proteins is crucial for unraveling key principles in cell biology. The reaction-diffusion model is commonly used to understand biochemical patterning; however, applying reaction-diffusion models to subcellular phenomena is challenging because of the difficulty in measuring protein diffusivity and interaction kinetics in the living cell. In this work, we investigated the self-organization of the plasmalemma vesicle-associated protein (PLVAP), which creates regular arrangements of fenestrated ultrastructures, using single-molecule tracking. We demonstrated that the spatial organization of the ultrastructures is associated with a decrease in the association rate by actin destabilization. We also constructed a reaction-diffusion model that accurately generates a hexagonal array with the same 130 nm spacing as the actual scale and informs the stoichiometry of the ultrastructure, which can be discerned only through electron microscopy. Through this study, we integrated single-molecule experiments and reaction-diffusion modeling to surpass the limitations of static imaging tools and proposed emergent properties of the PLVAP ultrastructure.

Advancements in neural interface technologies have enabled the direct connection of neurons and electronics, facilitating chemical communication between neural systems and external devices. One promising approach is a synaptogenesis-involving method, which offers an opportunity for synaptic signaling between these systems. Janus synapses, one type of synaptic interface utilizing synaptic cell adhesion molecules for interface construction, possess unique features that enable the determination of location, direction of signal flow, and types of neurotransmitters involved, promoting directional and multifaceted communication. This study presents the first successful establishment of a Janus synapse between dopaminergic (DA) neurons and abiotic substrates by using a neuroligin-2 (NLG2)-mediated synapse-inducing method. NLG2 immobilized on gold-coated microspheres can induce synaptogenesis upon contact with spatially isolated DA axons. The induced DA Janus synapses exhibit stable synaptic activities comparable to that of native synapses over time, suggesting their suitability for application in neural interfaces. By calling for DA presynaptic organizations, the NLG2-immobilized abiotic substrate is a promising tool for the on-site detection of synaptic dopamine release.

Hardware security is not a new problem but is ever-growing in consumer and medical domains owing to hyperconnectivity. A physical unclonable function (PUF) offers a promising hardware security solution for cryptographic key generation, identification, and authentication. However, electrical PUFs using nanomaterials or two-dimensional (2D) transition metal dichalcogenides (TMDCs) often have limited entropy and parameter space sources, both of which increase the vulnerability to attacks and act as bottlenecks for practical applications. We report an electrical PUF with enhanced entropy as well as parameter space by incorporating 2D TMDC heteronanostructures into field-effect transistors (FETs). Lateral heteronanostructures of 2D molybdenum disulfide and tungsten disulfide serve as a potent entropy source. The variable feature of FETs is further leveraged to enhance the parameter space that provides multiple challenge-response pairs, which are essential for PUFs. This combination results in stably repeatable yet highly variable FET characteristics as alternative electrical PUFs. Comprehensive PUF performance analyses validate the bit uniformity, reproducibility, uniqueness, randomness, false rates, and encoding capacity. The 2D material heteronanostructure-driven electrical PUFs with strong FET-to-FET variability can potentially be augmented as an immediately deployable and scalable security solution for various hardware devices.

Tumor-derived extracellular vesicles (TDEs) have potential for therapeutic cancer vaccine applications since they innately possess tumor-associated antigens, mediate antigen presentation, and can incorporate immune adjuvants for enhanced vaccine efficacy. However, the original TDEs also contain immune-suppressive proteins. To address this, we proposed a simple yet powerful preconditioning method to improve the overall immunogenicity of the TDEs. This approach involved inducing endoplasmic reticulum (ER) stress on parental tumor cells via N-glycosylation inhibition with tunicamycin. The generated immunogenic TDEs (iTDEs) contained down-regulated immunosuppressive proteins and up-regulated immune adjuvants, effectively activating dendritic cells (DCs) in vitro . Furthermore, in vivo evidence from a tumor-bearing mouse model showed that iTDEs activated DCs, enabling cytotoxic T lymphocytes (CTLs) to target tumors, and eventually established a systemic antitumor immune response. Additionally, iTDEs significantly delayed tumor recurrence in a postsurgery model compared with control groups. These findings highlight the immense potential of our strategy for utilizing TDEs to develop effective cancer vaccines.

It is critical to understand the laws of quantum mechanics in transformative technologies for computation and quantum information science applications to enable the ongoing second quantum revolution calls. Recently, spin qubits based on point defects have gained great attention, since these qubits can be initiated, selectively controlled, and read out with high precision at ambient temperature. The major challenge in these systems is controllably generating multiqubit systems while properly coupling the defects. To address this issue, we began by tackling the engineering challenges these systems present and understanding the fundamentals of defects. In this regard, we controllably generate defects in MoS 2 and WS 2 monolayers and tune their physicochemical properties via proton irradiation. We quantitatively discovered that the proton energy could modulate the defects' density and nature; higher defect densities were seen with lower proton irradiation energies. Three distinct defect types were observed: vacancies, antisites, and adatoms. In particular, the creation and manipulation of antisite defects provides an alternative way to create and pattern spin qubits based on point defects. Our results demonstrate that altering the particle irradiation energy can regulate the formation of defects, which can be utilized to modify the properties of 2D materials and create reliable electronic devices.

Aqueous zinc-vanadium hybrid redox flow battery systems are an efficient strategy to address the problems of low voltage and high cost of conventional all-vanadium redox flow batteries. However, the low electrochemical activity of carbon-based electrodes toward a vanadium redox reaction limits the performance of redox flow batteries. In this study, polyhedral binary cerium titanium oxide (Ce 2/3 TiO 3 , CTO) is synthesized using molten salt synthesis. CTO is fabricated by adjusting the temperature and composition. Notably, the prepared CTO obtained at 1000 °C shows the highest catalytic activity for a VO 2+ /VO 2 + redox reaction. Further, CTO is prepared as a composite electrocatalyst and applied to a high-voltage aqueous zinc-vanadium redox flow battery. The cell adopts an alkali zinc electrolyte containing a Zn/[Zn(OH) 4 ] 2- redox pair and exhibits a high operating voltage of 2.26 V. Remarkably, a zinc-vanadium redox flow battery using the composite electrocatalyst exhibits a high energy density of 42.68 Wh L -1 at 20 mA cm -2 and an initial voltage efficiency of 90.3%. The excellent cell performance is attributed to structural defects caused by A-site deficiency in the perovskite oxide structure as well as oxygen vacancies resulting from the low valence state of the metal ion, which enhance the catalytic activity of the vanadium ions.

In this paper, we demonstrate low-thermal-budget ferroelectric field-effect transistors (FeFETs) based on the two-dimensional ferroelectric CuInP 2 S 6 (CIPS) and oxide semiconductor InZnO (IZO). The CIPS/IZO FeFETs exhibit nonvolatile memory windows of ∼1 V, low off-state drain currents, and high carrier mobilities. The ferroelectric CIPS layer serves a dual purpose by providing electrostatic doping in IZO and acting as a passivation layer for the IZO channel. We also investigate the CIPS/IZO FeFETs as artificial synaptic devices for neural networks. The CIPS/IZO synapse demonstrates a sizable dynamic ratio (125) and maintains stable multilevel states. Neural networks based on CIPS/IZO FeFETs achieve an accuracy rate of over 80% in recognizing MNIST handwritten digits. These ferroelectric transistors can be vertically stacked on silicon complementary metal-oxide semiconductor (CMOS) with a low thermal budget, offering broad applications in CMOS+X technologies and energy-efficient 3D neural networks.

Olfaction, a primal and effective sense, profoundly impacts our emotions and instincts. This sensory system plays a crucial role in detecting volatile organic compounds (VOCs) and realizing the chemical environment. Animals possess superior olfactory systems compared to humans. Thus, taking inspiration from nature, artificial olfaction aims to achieve a similar level of excellence in VOC detection. In this study, we present the development of an artificial olfaction sensor utilizing a nanostructured bio-field-effect transistor (bio-FET) based on transition metal dichalcogenides and the Drosophila odor-binding protein LUSH. To create an effective sensing platform, we prepared a hexagonal nanoporous structure of molybdenum disulfide (MoS 2 ) using block copolymer lithography and selective etching techniques. This structure provides plenty of active sites for the integration of the LUSH protein, enabling enhanced binding with ethanol (EtOH) for detection purposes. The coupling of the biomolecule with EtOH influences the bio-FETs potential, which generates indicative electrical signals. By mimicking the sniffing techniques observed in Drosophila , these bio-FETs exhibit an impressive limit of detection of 10 -6 % for EtOH, with high selectivity, sensitivity, and detection ability even in realistic environments. This bioelectric sensor demonstrates substantial potential in the field of artificial olfaction, offering advancements in VOC detection.

The development of heavy-atom-free photosensitizers (PSs) for photodynamic therapy (PDT) has encountered significant challenges in achieving simultaneous high fluorescence emission and reactive oxygen species (ROS) generation. Moreover, the limited water solubility of these PSs imposes further limitations on their biomedical applications. To overcome these obstacles, this study presents a molecular design strategy employing hydrophilic heavy-atom-free PSs based on imidazolium salts. The photophysical properties of these PSs were comprehensively investigated through a combination of experimental and theoretical analyses. Notably, among the synthesized PSs, the ethylcarbazole-naphthoimidazolium ( NI-Cz ) conjugate exhibited efficient fluorescence emission (Φ F = 0.22) and generation of singlet oxygen (Φ Δ = 0.49), even in highly aqueous environments. The performance of NI-Cz was validated through its application in fluorescence bioimaging and PDT treatment in HeLa cells. Furthermore, NI-Cz holds promise for two-photon excitation and type I ROS generation, nucleus localization, and selective activity against Gram-positive bacteria, thereby expanding its scope for the design of heavy-atom-free PSs and phototheranostic applications.

Multistimuli responsive materials are advantageous in that they can enhance the desired response or bypass unwanted reactions. Light is one of the most attractive stimuli since it allows remote spatiotemporal control and multiplexing of properties (e.g., wavelength, intensity, irradiation time, pulsed/continuous wave) for application on multiphotoresponsive materials. However, the operating wavelength for such photoresponsive systems often includes an ultraviolet (UV) range that limits its use in the biomedical field. Herein, we investigate near-infrared (NIR)/visible (Vis) light-responsive nanocomposite films composed of rare earth element (i.e., Yb, Er)-doped NaYF 4 nanoparticles (NPs) embedded in azobenzene-incorporated poly(dimethylsiloxane) (AzoPDMS), silk fibroin, and silver nanowire (AgNW) layers. Photobending (PB) of the nanocomposite film is induced by a Vis light of 400-700 nm, while upconversion photoluminescence (UCPL) of embedded NPs is activated by an NIR light of 980 nm. The excitation wavelength of photoluminescence (PL) is shifted to the NIR (λ = 980 nm) range via photon upconversion in rare earth element-doped NPs. Independent operation of PB and UCPL enables both on-demand electrical switching and real-time location monitoring for spatiotemporally controlled electrical pulse stimulation. As a result, the dual-photoresponsive nanocomposite film can be utilized as a remotely controllable electrical stimulator and location indicator via different wavelengths of light.

Various redox couples have been reported to increase the energy density and reduce the price of redox flow batteries (RFBs). Among them, the vanadium electrolyte is mainly used due to its high solubility, but electrode modification is still necessary due to its low reversibility and sluggish kinetics. Also, an incompatible ion exchange membrane with redox-active species leads to self-discharge referred to as crossover. Here, we report a V/Mn RFB using an anion exchange membrane (AEM) for crossover mitigation and etched carbon felt by nickel-bismuth (NB-ECF) for the vanadium anolyte. The NB-ECF significantly enhances the reversibility and kinetics of the V 2+ /V 3+ redox reaction, attributed to inhibited irreversible hydrogen evolution by the Bi catalyst and increased carboxyl groups by nickel (etching and NiO catalyst). Notably, the V/Mn cell employed in the NB-ECF maintains a high energy efficiency of 85.7% during 50 cycles without capacity degradation at a current density of 20 mA cm -2 , which is attributed to a synergistic effect of crossover mitigation and facilitated V 2+ /V 3+ redox reaction. This study demonstrates the novel electrocatalyst design of carbon felt using two metal species.

We report a simple and environmentally friendly method for synthesizing N-containing heterocycles via a visible-light-mediated aerobic dehydrogenation reaction. Using a nontoxic, stable, and inexpensive titanium dioxide catalyst, a variety of substituted quinoline, indole, quinoxaline, and 3,4-dihydroisoquinoline derivatives could be synthesized using the green oxidant molecular oxygen. Improved reactivity and scalability of this reaction were demonstrated by adapting the photochemical multiphasic reaction to a continuous flow system. To gain insight into the mechanism, we also conducted several mechanistic studies, including absorption analysis, light on-off testing, and NMR analysis. Especially, oxygen is reduced to hydrogen peroxide, and dimethyl sulfoxide is a critical scavenger of the oxidant byproduct for ensuring high yields.

The immune response against a tumor is characterized by the interplay among components of the immune system and neoplastic cells. Here, we bioprinted a model with two distinct regions containing gastric cancer patient-derived organoids (PDOs) and tumor-infiltrated lymphocytes (TILs). The initial cellular distribution allows for the longitudinal study of TIL migratory patterns concurrently with multiplexed cytokine analysis. The chemical properties of the bioink were designed to present physical barriers that immune T-cells must breech during infiltration and migration toward a tumor with the use of an alginate, gelatin, and basal membrane mix. TIL activity, degranulation, and regulation of proteolytic activity reveal insights into the time-dependent biochemical dynamics. Regulation of the sFas and sFas-ligand present on PDOs and TILs, respectively, and the perforin and granzyme longitudinal secretion confirms TIL activation when encountering PDO formations. TIL migratory profiles were used to create a deterministic reaction-advection diffusion model. The simulation provides insights that decouple passive from active cell migration mechanisms. The mechanisms used by TILs and other adoptive cell therapeutics as they infiltrate the tumor barrier are poorly understood. This study presents a pre-screening strategy for immune cells where motility and activation across ECM environments are crucial indicators of cellular fitness.

Lithium-oxygen batteries have the potential to become the most eminent solution for future energy storage with their theoretical energy density exceeding all existing batteries. However, the insulating and insoluble discharge product (lithium peroxide; Li 2 O 2 ) impairs practical application. Conventional catalyst designs based on the electronic structure and interfacial charge transfer descriptors have not been able to overcome these limitations due to Li 2 O 2 . Herein, we revisit the role of heterogeneous catalysts as substrates to regulate Li 2 O 2 growth and the formation of solid/solid reaction interfaces. We demonstrate that controlled solid/solid interfacial structure design is a critical performance parameter beyond the inherent electronic structure. In particular, the Cu 2 O substrate in this study induces a homogeneous deposition of Pd atoms, which leads to well-controlled growth of Li 2 O 2 resolving mass and charge transport limits (i.e., the bottleneck of oxygen reduction/evolution reactions), thus improving reversibility, capacity, and durability of the cells by dissipating electrochemical and mechanical stress. We thus verified the essential role of solid/solid interfaces to regulate the nucleation and growth process of Li 2 O 2 in lithium-oxygen batteries.

Conventional titanium (e.g., bulk or thin films) is well-known for its relatively high mechanical strength, excellent corrosion resistance, and superior biocompatibility, which are suitable for biomedical engineering and wearable devices. However, the strength of conventional titanium often trades off its ductility, and their use in wearable devices has not been explored yet. In this work, we fabricated a series of large-sized 2D titanium nanomaterials with the method of polymer surface buckling enabled exfoliation (PSBEE), which possess a unique heterogeneous nanostructure containing nanosized titanium, titanium oxide, and MXene-like phases. As a result, these 2D titaniums exhibit both superb mechanical strength (6-13 GPa) and remarkable ductility (25-35%) at room temperature, outperforming all other titanium-based materials reported so far. More interestingly, we demonstrate that the 2D titanium nanomaterials also showed good performance in triboelectric sensing and can be used to fabricate self-powered, on-skin conformal triboelectric sensors with good mechanical reliability.

As a new enabling nanotechnology tool for wireless, target-specific, and long-distance stimulation of mechanoreceptors in vivo , here we present a hydrogel magnetomechanical actuator (h-MMA) nanoparticle. To allow both deep-tissue penetration of input signals and efficient force generation, h-MMA integrates a two-step transduction mechanism that converts magnetic anisotropic energy to thermal energy within its magnetic core ( i . e ., Zn 0.4 Fe 2.6 O 4 nanoparticle cluster) and then to mechanical energy to induce the surrounding polymer ( i . e ., pNiPMAm) shell contraction, finally delivering forces to activate targeted mechanoreceptors. We show that h-MMAs enable on-demand modulation of Notch signaling in both fluorescence reporter cell lines and a xenograft mouse model, demonstrating its utility as a powerful in vivo perturbation approach for mechanobiology interrogation in a minimally invasive and untethered manner.

Conductive fibers are core materials in textile electronics for the sustainable operation of devices under mechanical stimuli. Conventional polymer-metal core-sheath fibers were employed as stretchable electrical interconnects. However, their electrical conductivity is severely degraded by the rupture of metal sheaths at low strains. Because the core-sheath fibers are not intrinsically stretchable, designing a stretchable architecture of interconnects based on the fibers is essential. Herein, we introduce nonvolatile droplet-conductive microfiber arrays as stretchable interconnects by employing interfacial capillary spooling, motivated by the reversible spooling of capture threads in a spider web. Polyurethane (PU)-Ag core-sheath (PU@Ag) fibers were prepared by wet-spinning and thermal evaporation. When the fiber was placed on a silicone droplet, a capillary force was generated at their interface. The highly soft PU@Ag fibers were fully spooled within the droplet and reversibly uncoiled when a tensile force was applied. Without mechanical failures of the Ag sheaths, an excellent conductivity of 3.9 × 10 4 S cm -1 was retained at a strain of 1200% for 1000 spooling-uncoiling cycles. A light-emitting diode connected to a multiarray of droplet-PU@Ag fibers exhibited stable operation during spooling-uncoiling cycles.

Significant effort for demonstrating a gallium nitride (GaN)-based ferroelectric metal-oxide-semiconductor (MOS)-high-electron-mobility transistor (HEMT) for reconfigurable operation via simple pulse operation has been hindered by the lack of suitable materials, gate structures, and intrinsic depolarization effects. In this study, we have demonstrated artificial synapses using a GaN-based MOS-HEMT integrated with an α-In 2 Se 3 ferroelectric semiconductor. The van der Waals heterostructure of GaN/α-In 2 Se 3 provides a potential to achieve high-frequency operation driven by a ferroelectrically coupled two-dimensional electron gas (2DEG). Moreover, the semiconducting α-In 2 Se 3 features a steep subthreshold slope with a high ON/OFF ratio (∼10 10 ). The self-aligned α-In 2 Se 3 layer with the gate electrode suppresses the in-plane polarization while promoting the out-of-plane (OOP) polarization of α-In 2 Se 3 , resulting in a steep subthreshold slope (10 mV/dec) and creating a large hysteresis (2 V). Furthermore, based on the short-term plasticity (STP) characteristics of the fabricated ferroelectric HEMT, we demonstrated reservoir computing (RC) for image classification. We believe that the ferroelectric GaN/α-In 2 Se 3 HEMT can provide a viable pathway toward ultrafast neuromorphic computing.

In this study, to obtain high performances of the dye-sensitized solar cells using the optimal TiO 2 photoelectrode for the synthesized pyrazine-based organic photosensitizers, three types of TiO 2 photoelectrodes were fabricated and evaluated for comparison. The double-layered nanoporous TiO 2 photoelectrode (SPD type) consisted of a dispersed TiO 2 layer and a transparent TiO 2 layer. The single-layered nanoporous TiO 2 photoelectrodes (D type and SP type) consisted of a dispersed TiO 2 layer and a transparent TiO 2 layer, respectively. The surface area, pore volume, and crystalline structures of the three types of TiO 2 photoelectrodes were analyzed by Brunauer-Emmett-Teller method, field-emission scanning electron microscopy, and X-ray diffractometry to confirm their crystallinity and surface morphology. The structures of the three types of TiO 2 photoelectrode-adsorbed organic sensitizers were investigated using X-ray photoelectron spectroscopy. The photovoltaic performances of DSSC devices using three organic photosensitizers adsorbed onto the three types of TiO 2 photoelectrodes were investigated under a light intensity of 100 mW/cm 2 at AM 1.5. The DSSC device using double-layered SPD type TiO 2 photoelectrodes displayed 1.31∼2.64% efficiency, compared to single-layered SP type TiO 2 photoelectrodes (1.31∼2.50%) and D type TiO 2 photoelectrodes (0.90∼1.54%), using organic photosensitizers. The DSSC device using the SPD type TiO 2 photoelectrode and trifluoromethylbenzopyrazine (TPPF) as a photosensitizer showed the highest performances: J sc of 5.69 mA/cm 2 , V oc of 0.69 V, FF of 0.67, and efficiency of 2.64%. The relationship between photovoltaic effects and interfacial resistance characteristics of DSSCs using the three organic photosensitizers adsorbed onto the three types of TiO 2 photoelectrodes could be interpreted from interfacial resistances according to frequency through impedance analysis., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Cancer stem cells (CSCs) are associated with the invasion and metastatic relapse of various cancers. However, current cancer therapies are limited to targeting the bulk of primary tumor cells while remaining the CSCs untouched. Here, we report a new proton (H + ) modulation approach to selectively eradicate CSCs via cutting off the H + leaks on the inner mitochondrial membrane (IMM). Based on the fruit extract of Gardenia jasminoides , a multimodal molecule channel blocker with high biosafety, namely, Bo-Mt-Ge , is developed. Importantly, in this study, we successfully identify that mitochondrial uncoupling protein UCP2 is closely correlated with the stemness of CSCs, which may offer a new perspective for selective CSC drug discovery. Mechanistic studies show that Bo-Mt-Ge can specifically inhibit the UCP2 activities, decrease the H + influx in the matrix, regulate the electrochemical gradient, and deplete the endogenous GSH, which synergistically constitute a unique MoA to active apoptotic CSC death. Intriguingly, Bo-Mt-Ge also counteracts the therapeutic resistance via a two-pronged tactic: drug efflux pump P-glycoprotein downregulation and antiapoptotic factor (e.g., Bcl-2) inhibition. With these merits, Bo-Mt-Ge proved to be one of the safest and most efficacious anti-CSC agents, with ca. 100-fold more potent than genipin alone in vitro and in vivo. This study offers new insights and promising solutions for future CSC therapies in the clinic.

Gibberellins (GAs) are a class of phytohormones, important for plant growth, and very difficult to distinguish because of their similarity in chemical structures. Herein, we develop the first nanosensors for GAs by designing and engineering polymer-wrapped single-walled carbon nanotubes (SWNTs) with unique corona phases that selectively bind to bioactive GAs, GA 3 and GA 4 , triggering near-infrared (NIR) fluorescence intensity changes. Using a new coupled Raman/NIR fluorimeter that enables self-referencing of nanosensor NIR fluorescence with its Raman G-band, we demonstrated detection of cellular GA in Arabidopsis , lettuce, and basil roots. The nanosensors reported increased endogenous GA levels in transgenic Arabidopsis mutants that overexpress GA and in emerging lateral roots. Our approach allows rapid spatiotemporal detection of GA across species. The reversible sensor captured the decreasing GA levels in salt-treated lettuce roots, which correlated remarkably with fresh weight changes. This work demonstrates the potential for nanosensors to solve longstanding problems in plant biotechnology.

Aqueous zinc-based redox flow batteries are promising large-scale energy storage applications due to their low cost, high safety, and environmental friendliness. However, the zinc dendritic growth has depressed the cycle performance, stability, and efficiency, hindering the commercialization of the zinc-based redox flow batteries. We fabricate the carbon felt modified with bimodal sized tin and copper clusters (SCCF) with the electrometallic synthesis in a continuous-flow cell. The SCCF electrode provides a larger zinc nucleation area and lower overpotential than pristine carbon felt, which is ascribed to the well-controlled interfacial interaction of bimodal tin and copper particle clusters by suppressing unwanted alloy formation. The zinc symmetric flow battery and the zinc-based hybrid redox flow battery show the improved zinc plating and stripping efficiency. The SCCF electrode exhibits 75% improved cycling stability compared to the pristine carbon felt electrode in the zinc symmetric flow battery. Notably, the high-voltage aqueous zinc-vanadium redox flow battery demonstrates a high average cell voltage of 2.31 V at 40 mA cm -2 , showing a Coulombic efficiency of 99.9% and an energy efficiency of 87.6% for 100 cycles. We introduce a facile strategy to suppress the zinc dendritic growth, enhancing the performance of the zinc-based redox flow batteries.

Surface-aligned liquid-crystal networks (LCNs) offer a solution for developing functional materials capable of performing a range of tasks, including actuation, shape memory, and surfaces patterning. Here we show that Diels-Alder cycloaddition can be used to prepare the backbone of planar aligned LCNs under mild ambient conditions without the addition of additives or UV irradiation. The mechanical properties of the networks have robust viscoelastic modulus and stiffness with a reversible local free volume change upon physical aging. This study shows new opportunities to design surface-aligned LCNs based on additive free step-growth Diels-Alder polymerization and enables the potential to incorporate a wider range of photochromic materials into LCNs.

As the turnaround time of diagnosis becomes important, there is an increasing demand for rapid, point-of-care testing (POCT) based on polymerase chain reaction (PCR), the most reliable diagnostic tool. Although optical components in real-time PCR (qPCR) have quickly become compact and economical, conventional PCR instruments still require bulky thermal systems, making it difficult to meet emerging needs. Photonic PCR, which utilizes photothermal nanomaterials as heating elements, is a promising platform for POCT as it reduces power consumption and process time. Here, we develop a photonic qPCR platform using hydrogel microparticles. Microparticles consisting of hydrogel matrixes containing photothermal nanomaterials and primers are dubbed photothermal primer-immobilized networks (pPINs). Reduced graphene oxide is selected as the most suitable photothermal nanomaterial to generate heat in pPIN due to its superior light-to-heat conversion efficiency. The photothermal reaction volume of 100 nL (predefined by the pPIN dimensions) provides fast heating and cooling rates of 22.0 ± 3.0 and 23.5 ± 2.6 °C s -1 , respectively, enabling ultrafast qPCR within 5 min only with optical components. The microparticle-based photonic qPCR facilitates multiplex assays by loading multiple encoded pPIN microparticles in a single reaction. As a proof of concept, four-plex pPIN qPCR for bacterial discrimination are successfully demonstrated.

Organic-inorganic hybrid perovskite nanoparticles (OIHP NPs) have attracted scientific attention owing to their efficient photoluminescence with optical tunability, which is highly advantageous for optoelectronic applications. However, the limited long-term stability of OIHP NPs has significantly hindered their practical application. Despite several synthetic strategies and encapsulation methods to stabilize OIHP NPs, complicated multi-step procedures are often required. In this study, we introduce an in situ ligand engineering method for stabilizing and controlling the optical properties of OIHP NPs using tetraalkylammonium (TAA) halides with various molecular structures at different concentrations. Our one-pot ligand engineering substantially enhanced the stability of the OIHP NPs without post-synthetic processes. Moreover, in certain cases, approximately 90% of the initial photoluminescence (PL) intensity was preserved even after a month under ambient conditions (room temperature, 20-50% relative humidity). To determine the role of ligand engineering in stabilizing the OIHP NPs, the surface binding properties of the TAA ligands were thoroughly analyzed using Raman spectroscopy. Specifically, the permanent positive charge of the TAA cations and consequent effective electrostatic interactions with the surfaces of the OIHP NPs are pivotal for preserving the initial PL intensity. Our investigation is beneficial for developing OIHP nanomaterials with improved stability and controlled photoluminescence for various optoelectronic applications, such as light-emitting devices, photosensitizers, photodetectors, photocatalysis, and solar cells.

We report a synthetic approach for heterometallic (Au-Pt-Au) nanorings with intertwined triple rings (NITs), wherein three differently sized metal circular nanorings concentrically overlap in a single entity. The synthetic method allows one to control the component of core nanorings (Au or Pt) with a tunable gap distance. The narrow circular nanogaps between inner and outer Au rings strongly enhance the electromagnetic near-field via intraparticle coupling of localized surface plasmon resonance, which realizes surface-enhanced Raman scattering (SERS) at the single-particle level. Importantly, when the component of the middle ring is Pt, in situ SERS measurement for electrochemical reactions on Pt domains could be monitored with electrochemical potential variations due to the near-field focusing that is assisted by plasmonically active inner and outer Au nanorings, which is not feasible with pure Pt nanoparticle systems. The resulting NIT systems are robust and may benefit the synthesis of complicated nanostructures, giving myriad applications.

Two-dimensional transition-metal dichalcogenide (TMD) materials have attracted increasing attention in efforts to overcome fundamental issues faced by the complementary metal-oxide-semiconductor industry. Multilayer TMD materials such as MoS 2 can be used for high-performance transistor-based applications; the drive currents are high and the materials handle low-frequency (LF) noise well. We fabricated double-gated multilayer MoS 2 transistors using the h-BN dielectric for the top gate and silicon dioxide for the bottom gate. We systemically investigated the bottom gate voltage ( V b )-controlled electrical characteristics and the top/bottom interface-coupling effects. The effective thickness of the MoS 2 channel ( t MoS 2 _eff ) was well modulated by V b , and t MoS 2 _eff reduction by negative V b dramatically improved the I on / I off ratio. Numerical simulation and analytical modeling with a variation of the depletion depth under different bias conditions verified the experimental results. We were also the first to observe V b -tuned LF noise characteristics. Here, we discuss the V b -affected series resistance and carrier mobility in detail. Our findings greatly enhance the understanding of how double-gated multilayer MoS 2 transistors operate and will facilitate performance optimization in the real world.