Advanced Materials Interfaces最新文献

Nucleic acid (NA) testing at the point-of-care requires efficient NA extraction followed by post-NA amplification to achieve necessary detection sensitivity. Nanofibers (NFs) are demonstrated to be an ideal solid surface in an NA extraction process but necessitate harsh conditions that interfere with the subsequent NA amplification process. It is demonstrated that novel, pH tunable, zwitterionic NFs composed of uncharged nylon doped with the weakly basic, cationic polyallylamine hydrochloride and the weakly acidic anionic polycarboxylic acid to address the issue. Unlike the other cationic polymers investigated, e.g. polybrene and polyaniline, these polymers allow efficient NA extraction in Tris-ethylenediamine tetra-acetic acid buffer under mild conditions (pH 4.5 containing 0.1% Tween 20 for adsorption, and pH 10 with 50 mM NaCl for elution). Adsorption and elution yields over 95% and 70%, respectively, are achieved. It also discovered a correlation between material morphologies and the NA extraction suggests that the combination of polymer chemistries and nanofiber morphologies facilitates efficient NA extraction at low concentrations (ng range) within a short time period (<10 min). Considering the simple protocols and instrument-free operation the as-developed NFs are highly attractive for use in sample-to-answer NA testing in point-of-care settings.

Doping silicon wafers without using highly toxic or corrosive chemical substances has become a critical issue for semiconductor device manufacturing. In this work, ultra-thin films of hydroxyapatite (Ca₅(PO₄)₃OH) are prepared by tethering by aggregation and growth (T-BAG), and further processed by spike annealing. Via in situ infrared (IR), the decomposition of hydroxyapatite and intermixing with the native silicon oxide is observed already at temperatures as low as 200 °C. Phosphate transport through the native silicon oxide is driven by a phase transformation into a more stable thermal oxide. At 700 °C, diffusion of phosphorus into the sub-surface region of oxide-free silicon is observed. In situ IR combined with electrical impedance spectroscopy (EIS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and X-ray photoelectron spectroscopy (XPS) measurements allows to conclude that the phosphorus is: i) transported through the silicon oxide barrier, ii)) diffused inside the oxide-free silicon, and iii) finally modified the electrical activity of the silicon wafer. To further explain the experimental findings, density-functional theory (DFT) is used to demonstrate the extent of the effect of phosphorus doping on the electronic nature of silicon surfaces, showing that even small amounts of doping can have a measurable effect on the electrical performance of semiconductor wafers.

Surface Chemistry

Co₃O₄ is enriched with defects using pulsed laser defect engineering in liquid (PUDEL), and its surface hydroxyls are probed with fluoride ions. This dual approach reveals a linear correlation between laser processing and surface hydroxyl density, which is also linked to enhanced oxygen evolution reaction (OER) activity. More details can be found in article 2400237 by Sven Reichenberger, Stephan Barcikowski, and co-workers.

Cadmium-free AgInZnS (AIZS) quantum dots (QDs) have garnered significant research interest for applications in light-emitting diodes (LEDs); however, their performance remains limited by insulating long-chain ligands. In this study, highly fluorescent orange-emitting AIZS QDs are synthesized by replacing long-chain 1-dodecanethiol (DDT) with short-chain 1-octanethiol (OTT), achieving photoluminescence quantum yields of up to 80% in solution and 60% in film. The incorporation of OTT in combination with oleic acid and oleylamine as co-capping ligands enabled excellent dispersion of the QDs in non-polar solvents. The resulting OTT-capped AIZS QDs exhibited improved film smoothness and reduced nonradiative recombination. Furthermore, all-solution-processed QD light-emitting diodes (QLEDs) are fabricated comprising indium tin oxide/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate/hole transporting layer/AIZS QDs/ZnO electron transporting layer/Al. The effects of OTT capping and the thickness of the AIZS emitting layer on device performance are systematically evaluated. As a result, the QLEDs demonstrated enhanced luminance and current efficiency, reaching 515 cd m⁻² and 0.4 cd A⁻¹ respectively, representing improvements of over 50% and 33% compared to devices utilizing DDT-capped AIZS QDs. This study presents a facile and effective approach for developing high-brightness AIZS QLEDs.

Implanted medical devices often face the challenge of infections, which can compromise their successful integration and use. To address this issue, this study demonstrates the covalent grafting of a tannin-based antimicrobial biopolymer tanfloc (TAN) onto the titania nanotube arrays (TiNTs) surface to enhance antibacterial properties. Due to its polyphenolic and ionic structural configuration, tanfloc possesses unique properties that enable it to interact with and disrupt bacterial cell walls and membranes. Combining the topographical effect of TiNTs with the inherent antibacterial properties of tanfloc, this approach aims to mitigate bacterial threats on medical implants effectively. The successful attachment of tanfloc on TiNTs is confirmed through X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR). The antibacterial and antibiofilm efficacy of the tanfloc-functionalized TiNTs is evaluated against Staphylococcus aureus (Gram-positive) and Pseudomonas aeruginosa (Gram-negative) bacteria. The findings suggest that the covalent conjugation of tanfloc onto TiNTs is a promising approach to improve the infection resistance of titanium-based medical implants, with potential applications in orthopedic, dental, and other biomedical device areas.

Two-photon lithography (TPL) is a powerful technique for creating 3D microarchitectures. Applied to high-refractive-index materials like ZrO₂, it promises advanced optics. This is the case of ZrO₂ host matrixes in combination with luminescent dopants. However, due to the nonideal crystallinity attained to the TPL pre-ceramic replica from a custom-made photoresin, the emission of lanthanide (Ln) dopants in ZrO₂ microarchitectures can be suboptimal. However, crystallinity exacerbated by annealing can promote Ln-emission, thereby enabling the integration of ceramic micro-optic into a low-temperature process. This work presents a photoresin containing a metal-organic monomer tailored for TPL, enabling the fabrication of Ln-doped tetragonal ZrO₂ (t-ZrO₂) microarchitectures. The emission properties of Ln-doped microarchitectures with trivalent Ln ions (Ln³⁺), i.e., Yb³⁺ (2.5 mol%), Er³⁺ (0.35 mol%), and Tm³⁺ (0.35 mol%) are studied. The results demonstrate that Ln emission is absent when annealing the microarchitectures at 600 °C. Annealing at 750 °C activates Ln³⁺ emissions, including ²F_5/2–²F_7/2 (infrared), ⁴S_3/2–⁴I_15/2 (green), and ³H₄–³F₆ (near-infrared) transitions corresponding to Yb, Er, and Tm species. Transmission electron microscopy (TEM) confirms that t-ZrO₂ crystallinity becomes more prominent at 750 °C, demonstrating the promotion of Ln emissions upon thermal treatment and underscoring the role of crystalline in TPL micro-optical ceramics.

In recent years, the understanding of the role of the immune system in tumor progression and metastasis is paving the way for the development of antitumoral strategies based on the delivery of immunotherapeutic agents. The engineering of stimuli-responsive nanocarriers able to release their payload in a controlled manner being able to boost potent and sustained immune responses against tumors has provided a powerful tool to eradicate tumors with extreme precision. Paramount advantages to trigger the immune system against tumors are the high selectivity and memory effect of immune response, which allows not only to eradicate primary and metastatic malignancies but also to avoid their relapse. In this review, the recent advances carried out in the development of smart nanocarriers for immunotherapy are presented.

Enhancing fiber surfaces through in situ growth of nanomaterials is known to improve fiber composite properties by enhancing the interface between the fiber and matrix. In this study, hydrothermal processes are used to achieve two types of interfacial modification for carbon fiber: zinc oxide nanowires (ZnO NWs) and nickel-based metal–organic frameworks (MOF). The interfacial strengths are evaluated using single fiber push-in tests via nanoindentation and the interfaces are analyzed through dynamic modulus-mapping. It is found that ZnO modification increases the interface strength by 9.40%, while MOF modification yields an even higher improvement of 16.34%. The load-displacement plots exhibit distinctive inflection points, elucidated through microstructural observations. Examining the modulus map of the interface region, a transition in the storage modulus from the fiber to the matrix is identified. A capillary flow-based model is developed to explain the resin penetration through nanoscale features. The findings reported here indicate that the timescale for resin absorption is significantly shorter than the curing timescales for the surface modifications explored in this study.

The multifunctional responsive interfaces of liquid crystal (LC) and water are employed in fundamental research (colloidal assembly) and promising applications (sensing, release, and material synthesis). The stagnant LC systems, however, limit their use in continuous, automated applications. A microfluidic platform is reported where stable LC flow is maintained between aqueous interfaces. The LC-water soft interface is defined by the preferential wetting of the two phases at the chemically heterogeneous microchannel interfaces. It is shown that the LC-water interfaces are stable up to significant pressure differences across the interfaces and maintain responsive characteristics. The stability is in a range to cover the perpendicular and flow-aligned regimes at low and high flow velocities, respectively, in co-current or counter-current flow configurations. The LC configuration at the vicinity of the aqueous interfaces is influenced by the shear induced by the bulk LC flow and by the contacting aqueous phases allowing modulation of the LC strain at the responsive interfaces. The simplicity of the construction and operation of the soft-interface LC flow platform shows promise and meets the fundamental requirements for their integration into next-generation autonomous platforms.