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Rhodamine derivatives, as a prominent class of fluorophores, have become indispensable in advanced material engineering and biomedical research due to their exceptional photostability and tunable optical characteristics. However, their practical implementation faces fundamental challenges: conventional proton-mediated spirolactone ring opening mechanisms severely compromise fluorescence performance, while conventional structural optimization approaches remain synthetically demanding with limited efficacy. We hereby present a novel Lewis acid-assisted activation strategy that enables reversible spirolactone ring opening in classical rhodamine systems. This innovative approach achieves remarkable fluorescence enhancement characterized by superior quantum yields (up to 95%) and prolonged excited state lifetimes. Notably, the Lewis acid coordination establishes precise photocontrol over the ring opening process. This breakthrough represents the first demonstration of a nondestructive activation pathway for rhodamine fluorophores, effectively converting the nonemissive spirolactone form into highly luminescent Lewis acid complexes while maintaining molecular integrity.

Electrochemical CO₂ reduction (eCO₂R) in acidic electrolytes is appealing due to its high CO₂ utilization efficiency. For this reaction, bismuth (Bi)-based catalysts have drawn considerable attention for their potential in producing formate/formic acid. However, the presynthesized materials for Bi-based catalysts often undergo restructuring during electrocatalysis, resulting in altered electrochemical performance. Furthermore, the mechanisms underlying the restructuring of Bi-based catalysts in acidic environments have not yet been clearly elucidated. Herein, distinct restructuring mechanisms are revealed in structurally different Bi-based compounds, such as Bi₉O_7.5S₆ and Bi₂O₂S. Among them, the Bi₉O_7.5S₆ precatalyst exhibits high selectivity and activity for formic acid production, attributed to its unique structure, featuring stacking of [Bi₂O₂]²⁺ and [BiS₂]^- layers. In contrast, the conventional Bi₂O₂S catalyst, characterized by alternating [Bi₂O₂]²⁺ layers with S^2- ions, delivers inferior eCO₂R performances. Quasi-in situ X-ray diffraction and in situ Raman spectra results reveal that metal elements situated between two [Bi₂O₂]²⁺ layers can resist decomposition and prevent the over-reduction of catalysts, leading to the restructuring in Bi/Bi₂O₂CO₃ composite material with active Bi-Bi₂O₂CO₃ interface for formic acid production. As a result, the Bi₉O_7.5S₆ precatalyst achieves a high Faraday efficiency above 95% at 100 mA cm^-2 and remarkable stability of 117 h in a flow cell.

Perovskite solar cells (PSCs) are emerging as a promising technology for indoor photovoltaics due to their high efficiency and cost-effective manufacturing. In this article, three strategies are explored to reduce costs and enable perovskite materials (PSK) as power sources for indoor internet of things (IoTs): 1) using dual perovskite absorber layer (PSK1/polyethylene glycol (PEG)/PSK2) to replace both the absorber and hole transport layers, 2) utilizing spray-coating for perovskite deposition under ambient conditions with 45%-65% relative humidity (RH), and 3) replacing metal electrodes with carbon electrodes. The dual absorber layer improves charge transport, while the spray-coating process minimizes solution waste, making large-scale production more feasible. Additionally, the use of PEG as an interlayer effectively enhances defect passivation, improving charge transport and stability. The proposed carbon-based device architecture offers the lowest material cost ($11.98 m^-2) and the modified levelized cost of electricity for indoor light (m-LCOE-i) of 1.54 ¢ Wh^-1, outperforming traditional Spiro-OMeTAD/Au or carbon designs along with enhancing the commercial viability of PSCs. To demonstrate its practicality, connected PSCs are utilized to power IoT devices for over a month under typical laboratory lighting conditions (300-400 lux) at 40%-65% RH.

HfO₂-based ferroelectric thin films exhibit promising potential for next-generation nonvolatile memories and neuromorphic devices. Achieving both high polarization and fast switching is required, but optimizing one of them can be at the cost of degrading the other. This study achieves simultaneous fast switching and high polarization in Hf_0.5Zr_0.5O₂ epitaxial films grown by pulsed laser deposition. The influence of redox conditions during film growth on the ferroelectric switching kinetics and domain wall motion is systematically explored. Switching spectroscopy and Rayleigh analysis reveal that optimized redox conditions, tuned by oxygen and argon pressures during Hf_0.5Zr_0.5O₂ deposition, enable both enhanced polarization and switching speeds. Switching time can be further shortened when the final polarization state is aligned with the internal electric fields. The study challenges the trade-off between switching speed and polarization, demonstrating that precise control of defects in the film can simultaneously optimize both.

Spirometry is influenced by the patient's subjective condition, which limits the reproducibility of diagnostic results despite being a key diagnostic tool for respiratory diseases. To overcome this, an extended-gate field-effect transistor-type aptasensor for detecting granzyme B (GzmB) and perforin (PRF) is introduced as a proof-of-concept for diagnosing localized immune responses in respiratory diseases. The novel GzmB and PRF aptamers are synthesized using systematic evolution of ligands by exponential enrichment and are subsequently truncated to enhance the target-binding affinity. Au-ReS₂ and the alternating current electrothermal flow technique are applied to amplify the biosensing signal and accelerate detection within 10 min, respectively. Under the 10% human serum, a linear response is observed depending on the target concentration, with the detection limits of 330 fM for GzmB and 440 fM for PRF. The targeted dual-biomarker indicates a strong clinical correlation with bronchial conditions in chronic obstructive pulmonary disease patients. The proposed device demonstrates clear advantages in rapid, selective, and sensitive detection, suggesting its use as a preemptive diagnostic tool for respiratory diseases. This approach is expected to establish promising diagnostic strategies for early detection and therapeutic monitoring of various respiratory diseases, potentially replacing conventional spirometry.

The COVID-19 pandemic has underscored the urgent need for broad-spectrum antivirals (BSAs) capable of countering diverse and rapidly emerging viral threats. Unlike virus-specific drugs, BSAs offer cross-family protection and can serve as adaptable therapeutic platforms for pandemic preparedness. Advances in nanotechnology have further strengthened this approach by improving the solubility, stability, and targeted delivery of antiviral agents. Several repurposed drugs, such as niclosamide, favipiravir, remdesivir, nitazoxanide, and zinc-ionophores, have demonstrated potential broad-spectrum activity when formulated at the nanoscale. These nanoengineered platforms enhance pharmacokinetic performance, tissue penetration, and bioavailability, thereby enabling lower effective doses and reduced systemic toxicity. Such nanotechnological strategies not only improve antiviral efficacy across multiple viral families, including Coronaviridae, Flaviviridae, Orthomyxoviridae, and Poxviridae, but also support scalable, cost-effective production suitable for global deployment. By integrating drug repurposing with nanoengineering, BSAs can form the cornerstone of future pandemic preparedness, bridging the gap between laboratory innovation and rapid clinical response to emerging infectious diseases.

The phenomenon of surface facet formation during ion implantation has captured considerable scientific and technological interest. Surface facets-including wavy, pyramidal, and terraced morphologies-are typically formed during off-normal keV and MeV ion beam implantation, and due to injected gas effects. In certain circumstances, these features may also emerge during irradiation at normal incidence: when differential sputtering occurs in biphasic regions, when contaminants are inadvertently added as dopants, or when the experimental arrangement permits the coimplantation of metals. The formation of surface nanopatterns in nanocrystalline nickel under high-temperature ion irradiation at normal incidence has been observed-a phenomenon that conventional mechanisms fail to explain. A novel mechanism driving nanopattern formation under these conditions is presented. These findings offer compelling evidence that facets result from voids forming on the surface and in its vicinity. A strong correlation between the crystallographic orientation and the facet type has also been identified. Specifically, grains oriented in the <100> and <111> directions display smooth and wavy morphologies, while grains with orientations in between exhibit more complex shapes. The research indicates that grains with low stress and surface energies tend to exhibit wavy facets, while higher values lead to the formation of more complex shapes.

Nanoscale tailoring of the optoelectronic response of 2D transition metal dichalcogenides semiconductor layers (TMD) is demonstrated thanks to a novel strain engineering approach based on grayscale thermal-Scanning Probe Lithography (t-SPL). This method allows the maskless nanofabrication of locally strained 2D MoS₂-Au lateral heterojunction nanoarrays that are characterized by lateral modulation of the electronic band structure. 2D MoS₂ layers are conformally transferred onto grayscale t-SPL templates characterized by periodic nanoarrays of deterministic faceted nanoridges. This peculiar morphology induces asymmetric and uniaxial strain accumulation in the 2D TMD material, allowing us to tailor their electrical work-function at the nanoscale level, as demonstrated by Kelvin Probe Force Microscopy. By tailoring the local morphology of the grayscale nanopatterns, the capability to control the strain-dependent electrical work function of the 2D TMD layers at the local scale is demonstrated. The modulation of the electronic response has been exploited to develop periodic nanoarrays of lateral heterojunctions endowed with asymmetric electrical response by simple maskless deposition of Au nanocontacts onto the strained 2D TMD layers. The locally strained Au-MoS₂ layers form asymmetric lateral heterojunctions with strain-modulated Schottky versus Ohmic behavior, thus representing a promising platform in view of tunable ultrathin nanoelectronics, nanophotonic, and sensing applications.

Unlike 2D frameworks where conductivity is largely confined to in-plane transport, the scu topology offers 3D conduction pathways that enhance bulk charge mobility. When integrated with redox-active species like tetrathiafulvalene (TTF), the scu architecture promotes electron transfer across the 3D network, enabling tunable conductivity. This article presents the construction of a 3-periodic (4,8)-c covalent organic framework (COF), TU-48, adopting a twofold interpenetrated scu net, achieved through the integration of a tetratopic D _2h-symmetric rectangular TTF structural motif and an octatopic D _2h-symmetric quadrangular prism linker. TU-48 exhibits high structural order, well-defined porosity, and redox-responsive electrochemical behavior. The high-connectivity 3D COF configuration ensures effective access to TTF redox centers, enabling controlled iodine oxidation and resulting in electrical conductivities of 4.3 × 10^-6 S cm^-1 at 298 K and 1.8 × 10^-4 S cm^-1 at 393 K. By demonstrating how enhanced structural connectivity in TTF-bridged 3D covalent lattices enables improved charge-transport properties, this research fuels innovation in sustainable energy storage solutions and electronics.

Despite advances in treatment and therapeutic strategies, patients with brain tumors, including glioblastoma (GBM) and meningioma, still face high rates of recurrence, morbidity, and mortality. Nonviral biodegradable nanoparticles are advanced materials with the potential to reprogram brain tumor cells and the tumor immune microenvironment. Localized delivery of poly(beta-amino ester) nanoparticles encapsulating immunostimulatory genes is utilized to reprogram brain tumor cells into tumor-associated antigen-presenting cells (tAPCs) by inducing overexpression of costimulatory 4-1BBL on the surface of brain tumor cells and IL-12 secreted into the tumor microenvironment. In both a humanized mouse model using human meningioma (IOMM-Lee) and an immunocompetent syngeneic orthotopic model using mouse GBM (CT-2A), delivery of 4-1BBL/IL-12 DNA-loaded nanoparticles results in reduced tumor growth, as well as complete tumor regression and long-term survival in some animals. The 4-1BBL/IL-12 gene delivery platform is an antigen-agnostic, off-the-shelf biotechnology that can successfully activate cytotoxic T-cells in tumors, improve tumor infiltration by immune cells, and enhance antitumor responses to otherwise refractory brain tumors. This nanoparticle reprogramming approach can lead to safe, long-lasting endogenous cellular immune responses that specifically target multiple types of brain tumors that exhibit antigen heterogeneity in a patient-accessible manner without using viruses or ex vivo cellular manufacturing.