Nano Convergence最新文献

A surface-enhanced Raman scattering (SERS)-based aptasensor was developed for the rapid and sensitive detection of Escherichia coli (E. coli), a major pathogen in urinary tract infections (UTIs). The sensor utilizes magnetic beads embedded with gold nanoparticles (MB-AuNPs) functionalized with capture DNA (cDNA) as both the SERS-active substrate and magnetic separation tool. The detection mechanism relies on an aptamer DNA-probe DNA complex: when the aptamer binds specifically to E. coli, the probe DNA is released and subsequently hybridizes with cDNA on the MB-AuNPs. This brings a Cy5 Raman label close to the gold surface, generating a strong SERS signal. The assay offers a one-step process, eliminating the need for bacterial culture or nucleic acid amplification, and completes within approximately 6 h. Quantitative analysis demonstrated a detection limit of 5.9 × 10³ CFU/mL, well below the clinical threshold for UTIs, with a reliable calibration curve (R² = 0.990). Selectivity tests confirmed high specificity for E. coli without cross-reactivity to other bacteria. Clinical evaluation using 21 urine samples showed high diagnostic performance: 100% sensitivity, 91% specificity, 95% accuracy, and 100% precision compared to standard urine culture. These results highlight the aptasensor’s potential as a rapid, sensitive, and specific alternative for UTI diagnosis in clinical settings.

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MXenes, a versatile family of two-dimensional (2D) transition metal carbides and nitrides, have attracted significant attention for battery applications due to their exceptional properties, such as high electronic conductivity, tunable microstructure, robust mechanical and chemical stability, and compositional diversity. However, despite these advantages, conventional MXene synthesis methods-relying heavily on toxic acid etching-pose serious environmental hazards, undermining their suitability for sustainable energy applications. In this context, eco-friendly and non-toxic MXene synthesis routes have become increasingly critical for enabling the widespread adoption of MXene, driving extensive research into alternative, green synthetic approaches. These recent advances in environmentally benign synthesis are pivotal to unlocking the full potential of MXenes for diverse next-generation battery technologies. In this review, we provide a comprehensive overview of green and sustainable MXene synthesis strategies, highlighting the latest developments that go beyond traditional fluorine-based routes. Each synthetic process is comparatively analyzed with respect to its efficacy, limitations, and implications for practical application as key functional components in lithium-ion batteries (LIBs) and post-LIB systems. Finally, we offer a perspective on how the development of eco-friendly MXenes can contribute to overcoming the industrial challenges facing advanced battery technologies.

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Wide bandgap (WBG) power semiconductors have attracted significant attention from both academia and industry because they are superior to conventional silicon-based devices. In WBG power semiconductor packages, die attach materials play a crucial role in maximizing device performance and reliability. The die attach interfaces in WBG packages must withstand high operating temperatures (200–300 °C), fast switching frequencies, and great power densities while maintaining excellent thermomechanical reliability. Traditional die attach materials have significant limitations when applied to WBG devices, which has led to intensive research into nanomaterial-based alternatives during the past decade. This review summarizes current state-of-the-art nano-enabled die attach technologies: nanocomposite solders, nano-sintering approaches, and novel nanomaterial formulations specifically engineered for WBG power semiconductor packages. We examine the fundamental mechanisms behind the performance of nanomaterial die attach solutions and their ability to address the thermal management challenges of WBG devices. Furthermore, we examine the reliability of these materials in extreme operating conditions by evaluating their thermal cycling performance, shear strength stability, and microstructural evolution.

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Highly oriented oxide thin films hold substantial relevance to a wide range of fields. A major challenge is their integration with technological substrates, such as flexible polymers and silicon. While multiple strategies for the lift-off and transfer of high-quality oxide thin films have been widely explored, it remains a challenge to easily transfer films with low defect levels. In this work, we introduce a novel and effective strategy for achieving high-quality, freestanding perovskite oxide thin films. We first demonstrate that highly oriented perovskite oxides, as both single-phase films and vertically aligned nanocomposite (VAN) films, can be grown by pulsed laser deposition on single crystal NaCl, as not shown before. We next show that the VAN films, unlike single-phase films, can be readily, electrostatically, dry lifted-off the substrate. The success of the lift-off technique is enabled by (i) a high thermal expansion mismatch of the film, producing compression in the film, and (ii) lack of elastic strain relief in the out-of-plane direction in the VAN film. Finally, we show that a VAN cathode film can be incorporated into a proof-of-concept micro-solid oxide fuel cell structure, and that it is of good structural quality as demonstrated by performance comparable to equivalent VAN films grown on single crystal YSZ. Thus, we developed an entirely new way to lift-off and transfer highly oriented oxide thin films for use in a wide variety of electronic applications.

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Single emitters in solid state are promising sources of single and entangled photons. To boost their extraction efficiency and tailor their emission properties, they are often incorporated in photonic nanostructures. However, achieving accurate and reproducible placement inside the cavity is challenging but necessary to ensure the highest mode overlap and optimal device performance. For many cavity types —such as photonic crystal cavities or circular Bragg grating cavities — even small displacements lead to a significantly reduced emitter-cavity coupling. For circular Bragg grating cavities, this yields a significant reduction in Purcell effect, a slight reduction in efficiency and it introduces polarization on the emitted photons. Here we show a method to achieve high accuracy and precision for deterministically placed cavities on the example of circular Bragg gratings on randomly distributed semiconductor quantum dots. We introduce periodic alignment markers for improved marker detection accuracy and investigate overall imaging accuracy achieving (9.1 ± 2.5) nm through image correction. Since circular Bragg grating cavities exhibit a strong polarization response when the emitter is displaced, they are ideal devices to probe the cavity placement accuracy far below the diffraction limit. From the measured device polarizations, we derive a total spatial process accuracy of (33.5 ± 9.9) nm based on the raw data, and an accuracy of (15 ± 11) nm after correcting for the system response, resulting in a device yield of 68% for well-placed cavities.

A significant amount of effort has been poured into optimizing the delivery system that is demanded by novel therapeutic modalities. Lipid nanoparticle presents as a solution to transfect cells safely and efficiently with nucleic acid-based therapeutics. Among the components that make up the lipid nanoparticle, ionizable lipids are crucial for the transfection efficiency. Traditionally, the design of ionizable lipids relies on literature search and personal experience. With advancements in computer science, we argue that the use of machine learning can accelerate the design of ionizable lipids systematically. Assuming researchers in lipid nanoparticle synthesis may come from various backgrounds, an entry-level guide is needed to outline and summarize the general workflow of incorporating machine learning for those unfamiliar with it. We hope this can jumpstart the use of machine learning in their projects.

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Real-time monitoring of the surrounding gas environment, including our inhaled and exhaled atmosphere, is a crucial but underdeveloped technology for personalized healthcare. Recent advancements in wearable sensing technologies and AI algorithms promise the realization of more powerful wearable gas sensing systems, such as electronic noses. However, fundamental studies are still ongoing in seeking efficient gas sensing materials, transducing mechanisms, and device structures to meet the basic requirement of wearability and low power operation. Low-dimensional metal chalcogenides have attracted significant attention in building flexible gas sensors with room-temperature operation. Their controllable synthesis and post-synthesis treatment allow precise manipulation of the gas adsorption and charge transfer process. Their high surface-to-volume ratio, abundant active surface sites, and tunable electronic properties enable high sensitivity and selectivity, and fast response/recovery even without thermal activation. This review begins with an overview of three transducing mechanisms, providing a comprehensive understanding of the gas sensing process. Aiming at achieving efficient transducers, different types of low-dimensional metal chalcogenides, especially the 0D quantum dots and 2D nanosheets families, have been discussed regarding their synthesis methods and key material design strategies. State-of-the-art low-dimensional metal chalcogenide gas sensors are analyzed based on their modifications to the gas adsorption energy, charge transfer rate, and other fundamental parameters. Moreover, potential system construction towards smart and wearable gas sensor devices has been described with the integration of diversified sensor arrays, wireless communication technologies, and AI algorithms. Finally, we propose the remaining challenges and outlook for developing low-dimensional metal chalcogenide wearable gas sensing and eventually achieving accurate gas mixture classification and odor recognition.

Due to a pivotal role in the post-transcriptional regulation of genes implicated in numerous diseases, miRNAs serve as promising disease biomarkers and therapeutic targets. We introduce a new oligonucleotide probe termed miRNA-trigger, which selectively downregulates newly assigned target mRNAs by hijacking specific miRNAs. By engineering the miRNA-trigger to suppress the anti-apoptotic BCL-xL gene, we induce apoptosis selectively in breast cancer cells overexpressing specific miRNAs and further validate its therapeutic efficacy in vivo, by significantly reducing the tumor volume of the xenograft mouse upon its tail-vein injection. This approach establishes a new platform for self-modulating oligonucleotide therapy by redirecting disease-associated miRNAs.

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Lanthanide-based inorganic nanomaterials have been widely utilized as luminescent materials for broad-ranging applications in lighting, display, and optoelectronic devices. Among lanthanide elements, divalent europium (Eu²⁺) has recently gained significant attention owing to its excellent photoluminescence (PL) properties, such as a short radiative decay lifetime, narrow PL bandwidth, and wide emission range from ultraviolet to near-infrared. Particularly, colloidal metal halide nanocrystals (MHNCs) offer unique advantages as inorganic hosts for Eu²⁺ owing to their excellent phase purity, chemical and optical stability, and colloidal stability for facile integration via solution processes. In addition, the PL properties of Eu²⁺, originating from the parity-allowed 4f–5d transitions, can be precisely controlled by tuning the phase and compositions of MHNCs. Therefore, an in-depth understanding of the Eu²⁺ PL mechanism and synthesis of phase-pure MHNCs is essential for the advancement of Eu²⁺-based MHNCs as novel emitters. This review summarizes recent developments in Eu²⁺-based colloidal MHNCs and their PL properties. First, the local factors affecting the luminescence properties of Eu²⁺ in inorganic hosts are discussed. Subsequently, recent advances in the synthesis of Eu²⁺-based MHNCs using different host–dopant frameworks, their optical proprieties, and applications are outlined. This comprehensive review provides valuable insights for designing high-performance emitters, particularly for achieving deep-blue emission in light-emitting diodes and high-energy scintillators.

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