ACS Applied Nano Materials最新文献

Core–shell magnetic nanoparticle (MNP)-based sensors have enabled homogeneous (wash-free) biosensing owing to their distinctive behavior during colloidal agglutination mediated by surface chemistry. Although MNPs have shown extensive utility in biomolecule labeling and separation, understanding the dynamics of MNP agglutination will further assist their optimization for biosensing applications, particularly for producing concentration-dependent sensor responses. In this study, we establish a design framework for MNP-based agglutination sensors that transduce magnetic relaxation into assay readouts. Carboxymethylated dextran-coated MNPs functionalized with biotin are incubated with streptavidin, and MNP cluster formation upon reaction is characterized using alternating current magnetization and dynamic light scattering. Our results reveal that receptor density is an effective control for manipulating the analyte-response region. Further, statistical analyses indicate that a logistic relation captures the essential behavior between analyte concentration and the resulting MNP agglutinate size. Importantly, this study connects nanoscale surface functionalization to agglutination-driven signal generation, providing practical guidance for engineering magnetic nanomaterials for applied sensing with enhanced sensitivity.

We report here the sol–gel synthesis of Ln(Mn_0.2Fe_0.2Co_0.2Ni_0.2Cu_0.2)O₃ (Ln= La, Ce, Pr, Nd, Sm, and Gd) high-entropy perovskite oxide (HEPO) materials that have subsequently been tested for the dry reforming of methane (DRM) reaction. Among the six lanthanide-based HEPOs, the pure-phase La(Mn_0.2Fe_0.2Co_0.2Ni_0.2Cu_0.2)O₃ catalyst has shown the highest catalytic activity, with 86% methane conversion and 90% CO₂ conversion for a 100 h DRM reaction with H₂/CO ∼ 1. Same catalyst synthesized by solution combustion synthesis route results in much lower activity behavior. The pristine HEPO phase of the catalyst decomposes in the DRM environment and can be regenerated from the individual oxide phases by in situ thermal treatment close to the phase formation temperature, without compromising the DRM activity. This outcome indicates an unusual reversible thermal switching between the pristine HEPO phase of the catalyst and the fragmented phases formed during DRM and highlights the need for further research into the function of the decomposed phases that are produced in situ. We have explored the structure–property correlation in the framework of an in situ generated nanocomposite at the molecular level of the promising HEPO catalyst.

Cyclodextrin-based nanosponges (NSs) have gained attention as sustainable adsorbents for emerging pollutants. However, conventional cyclodextrin cross-linking typically involves toxic solvents and prolonged reaction times, which complicate synthesis and purification. In this work, NSs were synthesized using a solvent-free mechanochemical process via mechanical milling with diphenyl carbonate as a cross-linker. The structural and physicochemical properties of the obtained NSs were characterized using morphological (FE-SEM, TEM, EDS), spectroscopic (FT-IR, Raman, NMR), thermal (TGA, DSC), and crystallographic (XRD) techniques, confirming successful cross-linking. The adsorption performance of the NSs was evaluated using dinotefuran, a model neonicotinoid pollutant. Kinetic and equilibrium studies revealed rapid adsorption within 60 min, with a removal efficiency (RE%) of 98%. The equilibrium data were best fitted by employing the Freundlich and Temkin isotherms, indicating a heterogeneous multilayer adsorption process dominated by supramolecular interactions. Notably, when tested in real river water samples from the Maipo River (Chile), the NSs maintained a high RE% of 75% and demonstrated stable performance over multiple adsorption–desorption cycles, confirming their reusability under environmentally relevant conditions. This sustainable and scalable synthesis approach, coupled with strong performance in both laboratory and natural water matrices, highlights the potential of these NSs as viable materials for water treatment applications.

Deep eutectic solvents (DES) are versatile solvents obtained by a mixture of components that results in a significant decrease in melting temperature. These systems have been widely described in the literature and can be suitable solvents for liquid–liquid extraction. Additionally, DES can be utilized in the synthesis media of metallic nanoparticles (NPs), allowing for control over growth, stabilization, and functionalization, while serving as an environmentally friendly alternative. In this study, we are merging the properties of DES as solvents and soft templates for nanomaterial synthesis to present an all-in-one sensing platform that extracts, preconcentrates, and probes species from hydrophobic analytical matrices such as margarine and oil. Through multivariate modeling, our approach achieved limits of detection on the order of 10^–6 mol L^–1 for the analyte extracted from margarine and oil. We demonstrate that DES-native NPs can be synthesized through a rapid procedure without the use of additional reducing agents, unlike other synthesis protocols. Also, the obtained NPs are highly stable against aggregation, making them suitable for both surface-enhanced Raman scattering (SERS) and plasmonic-colorimetric applications. Furthermore, the DES surrounding the NPs acts as an efficient extraction solvent, transferring the analyte from its matrix to the metal surface without the need for extra steps, thereby saving time and reagents in an entirely green procedure. Our results demonstrated that our approach can be easily optimized and customized, which, in the context of analytical SERS, circumvents one of its more challenging bottlenecks: performing SERS using colloidal NPs in hydrophobic media.

This work presents a comprehensive multiscale computational investigation of the complete adsorption–regeneration cycle of functionalized adsorbents for atmospheric water harvesting (AWH) under low-humidity conditions. The target system is copper-docked MOF-303, a nanoporous framework with well-defined nanoscale channels and adsorption sites, functionalized with Amino and Nitro clusters, selected to tailor host–guest interactions and optimize water uptake and release. The simulations capture key molecular-level phenomena including host–guest interactions, water mobility, adsorption kinetics, and regeneration temperatures, providing a detailed picture of performance under varying environmental conditions. Cu–NH₂@MOF-303 showed the highest water capacity, reaching a ∼38% increase over the pristine structure, while Cu–NO₂@MOF-303 achieves an improvement of ∼25%. The kinetics follow a similar trend: the pristine framework saturates in 4 min at 2000 Pa, whereas Cu–NH₂@MOF-303 reaches equilibrium almost instantaneously (∼0.1 min). Cu–NO₂@MOF-303 also accelerates uptake, saturating within <3 min at 2000 Pa. Density functional theory (DFT) results confirm the enhanced affinity, with adsorption energies shifting from −84.77 kJ mol^–1 in pristine MOF-303 to −99.93 kJ mol^–1 (Cu–NH₂) and −90.16 kJ mol^–1 (Cu–NO₂). Despite requiring a modestly higher regeneration temperature (≈25 K above pristine MOF-303), Cu–NH₂@MOF-303 offers a favorable balance between stronger binding and practical desorption, making it suitable for low-to-moderate relative humidity conditions.

We report two-dimensional (2D) metal–organic framework nanosheets (MONs) integrated with optical fiber (OF) that enable tunable light emission and biocompatible microendoscopy. Luminescent 2D frameworks based on Eu³⁺, Tb³⁺, and Y³⁺ ions are employed to produce freestanding MONs via freeze–thaw exfoliation, followed by integration onto the OF through solution dripping. The resulting MONs exhibit large aspect ratios of up to 2300:1 and display red, green, and blue photoluminescence (PL), respectively. Their integration with OFs enables PL color mixing, yielding tunable emission ranging from yellow to quasi-white. The MON-integrated OFs are subsequently used for light emission and in vivo microendoscopy of Casper fish, paving the way for efficient and sustainable 2D materials in optical and biomedical technologies.

Nucleic acids have long been recognized for their essential role in storing and transmitting genetic information. Inspired by the functional and recognition properties of DNA and RNA, we designed a class of nucleobase-appended bottlebrush polymers to serve as advanced surface ligands for stabilizing plasmonic nanomaterials. Leveraging multivalent metal–nucleobase interactions, these bottlebrush polymers provided robust protection to colloidal nanomaterials, preventing undesired aggregation under harsh conditions including high salt concentrations, broad pH ranges, freeze–thaw cycles, and elevated temperatures. Additionally, the surface attachment of polymer ligands enabled the phase transfer of nanoparticles from aqueous media to organic media. The customizable design of these polymeric ligands facilitates the further functionalization of ligand-protected nanoparticles. Compared to conventional thiol-based ligands, the nucleobase-functionalized bottlebrush ligands exhibited a superior ability to offer colloidal stability under harsh conditions, owing to their multivalent interactions. This unique stability will open opportunities for the development of advanced biosensing, imaging, and therapeutic applications.

Although hexacoordinated aluminum species exhibit moderate acidity, which is advantageous for many catalytic reactions relative to the stronger acidity of tetracoordinated aluminum, their structural instability in porous frameworks significantly limits the specific surface area and pore stability of materials. To address these challenges, we report an innovative stepwise deposition strategy for constructing Al₂O₃/MCM-41-x materials with γ-Al₂O₃ decorated in the inner wall of MCM-41. The inner aluminum deposition originated from the preferential hydrolysis of AlO₂^– remains hexacoordinated state as γ-Al₂O₃ generating moderately Lewis acid sites. The outer silica deposition layer forms an MCM-41 framework, resulting in long-range ordered mesoporous material Al₂O₃/MCM-41 with hexagonal channels. This structure delivers a high specific surface area while simultaneously enhancing the stability of Al₂O₃. With Al₂O₃/MCM-41 as support, the optimal catalyst Ru/Al₂O₃/MCM-41 achieved 97.1% aniline conversion (160 °C, 3.0 MPa H₂), a value three times higher than that of conventional Ru/Al₂O₃ (32.3%). This significant enhancement can be attributed to the synergistic effects of a high surface area, ordered mesoporous structure, and dominant Lewis acidity. This work establishes a pioneering structure featuring Al₂O₃ decoration in the mesopores of MCM-41 via stepwise deposition self-assembly strategy, providing a promising mesoporous support for hydrogenation catalysis and industrial applications.

Industrial waste containing synthetic dyes poses serious environmental problems, because these materials are difficult to break down and are chemically stable, leading to water pollution. Hence, it is crucial to develop ecofriendly and effective techniques for their removal. In this work, a PVDF-NaNbO₃-Mo₂AlB₂-based porous, flexible foam is synthesized as a catalyst using the solution casting method for the efficient removal of dyes. NaNbO₃ was prepared via a hydrothermal route, while Mo₂AlB₂ was obtained through high-temperature annealing. SEM analysis confirms the formation of a highly porous structure in the PVDF-based nanocomposite foam, while XRD results verify the successful formation and phase integration of the PVDF-NaNbO₃-Mo₂AlB₂ nanocomposite. The porous structure of the foam increases the active surface area, facilitating an efficient interaction with dye molecules. The synthesized foam utilizes tribo-induced piezocatalysis, where mechanical energy is converted to electrochemical potential through the combined effects of triboelectricity and piezoelectricity. The flexible PVDF matrix contributes triboelectric activity, NaNbO₃ provides a strong piezoelectric response, and Mo₂AlB₂ enhances charge transfer between the interfaces. The detailed structural characterizations revealed that the synthesized foam possesses a highly porous structure with a large surface area, confirming its well-developed morphology and composition. Under the effect of vortex-induced mechanical stress, the foam demonstrates notable catalytic activity, achieving degradation efficiency of 97% for Rhodamine B and 98% for Methylene Blue within 60 min, without any external light source or chemical oxidants. The catalyst shows good stability and reusability, maintaining a degradation efficiency of 90% even after five successive cycles. Furthermore, scavenger tests reveal that superoxide radicals (^•O₂^–) play the dominant role, while holes and hydroxyl radicals contribute to a lesser extent. In the future, such tribo-induced piezo systems can be further studied for large-scale environmental remediation and energy–environment coupling applications.

Owing to their potential applications in polarized optical encryption, biomedical imaging, and quantum information processing, CPL detection has garnered increasing research attention, particularly toward the development of integrated, high-performance, and broadband CPL photodetectors. However, the detection bandwidth of CPL devices based on chiral semiconductor photoactive nanomaterials is fundamentally constrained by their intrinsic optical bandgaps, making it challenging to achieve high-sensitivity CPL detection across a broad spectral range. In this work, we propose a ternary energy-level-bridged chiral organic photodetection system to effectively broaden the spectral response of CPL detectors. By integrating a chiral nanomolecular materials (TPPS), chiral polymeric nanowires (P₃TH), and PC₇₁BM, and by leveraging the strong spin–orbit coupling induced by molecular chirality together with an optimized energy-level alignment, we realize highly efficient photogenerated charge separation and transport under CPL excitation. Consequently, the CPL detection window is extended from 400–650 nm in the binary system to 350–650 nm in the ternary chiral organic semiconductor system. The ternary chiral organic CPL photodetector achieves a responsivity of 0.09 A W^–1 and a detectivity of 3.5 × 10¹² Jones, with the responsivity further enhanced to 0.14 A W^–1 in the visible region while maintaining a detectivity of 3.5 × 10¹² Jones. Moreover, the device exhibits excellent operational stability, with the photocurrent remaining nearly unchanged after more than 300 on–off switching cycles. This study presents a generally applicable strategy for spectral broadening and performance enhancement of chiral semiconductor–based CPL photodetectors via energy-level engineering and chirality-induced spin–orbit coupling. The approach provides a solid foundation for advancing their practical implementation in integrated optoelectronic systems.