Due to its superior physical and chemical characteristics, MXene quantum dots (MXQDs) are regarded as an outstanding zero-dimensional nanomaterial. The excitation of these QDs dependent on emission properties, photostability, biocompatibility...
A comprehensive study is reported on two types of 3D graphene foam (GF) exhibiting distinct defect density, structural and functional properties. Wettability characterization demonstrates that high defect GF and low defect GF are hydrophilic, with a contact angle (CA) of approximately 14° and 72°, respectively. Optical characterization demonstrates close to zero reflectance and transmittance over a spectral range of 350 nm to 25 µm. X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDS) provide insight into chemical composition, defect density, and functionalization, while atomic force microscopy (AFM) shows that the high defect GF (HDGF) has a pronounced surface roughness, with a maximum surface roughness of over 18 nm. However the low defect GF (LDGF) exhibits a significantly smoother and more uniform surface with a maximum surface height of 4.5 nm. Electrochemical characterization demonstrates the impact of network connectivity on charge transport, highlighting differences in resistance and percolation thresholds between the two HDGF and LDGF foam types with areal capacitances of 38 and 32 µF cm-2, respectively, at a current density of 0.1 mA cm-2. The values show 90% and 94% retention of the initial capacitance when current density was increased 50-fold. A detailed structure-property-function relationship is established for the GF materials, useful for various applications.
Access to sub-micrometer electrode patterning remains limited in laboratories without lithographic or specialized mask-fabrication facilities. We present a novel, low-cost method for fabricating microdevices using nail-polish microfibers as shadow masks. A thin fiber is drawn by repeatedly touching a nail-polish droplet with a wire loop and placed directly onto the target substrate to define narrow features for metal deposition. As-drawn fibers reach diameters down to ∼2 µm and conform to both rigid and flexible surfaces. Oxygen-plasma thinning at ∼22 nm min-1 reduces fibers initially ≥4 µm in diameter to below 1 µm, enabling electrode gaps down to ∼478 nm, as confirmed by atomic force microscopy. The process requires no spin-coated photoresist, baking, or development. Using this approach, we pattern microelectrodes on SiO2/Si and polycarbonate and realize functional devices, including MoS2 field-effect transistors, MoS2 photodetectors, and a flexible device based on chemical vapor deposition-grown MoS2. The method requires no photolithography, minimizes material cost, and leverages readily available tools and consumables, providing a practical route to prototyping and education as well as laboratory microfabrication.
The scalable production of graphene with controlled chemical functionalities remains a central challenge in translating laboratory advances into practical technologies. Beyond conventional approaches that prioritize the surface area, functionalization or conductivity, increasing attention is being directed toward spatially selective defect engineering that preserves the aromatic π-conjugated carbon framework while enabling targeted interfacial reactivity, thereby providing high-quality graphene. In this context, shear-driven ball milling has emerged as a promising mechanochemical route for the synthesis of edge-functionalized graphene through preferential edge activation and controlled exfoliation. Unlike oxidation-intensive methods that often introduce extensive basal-plane damage, shear-assisted milling promotes layer delamination while largely preserving the intrinsic sp2 carbon network. Simultaneously, the mechanochemical environment activates newly generated edge sites, enabling direct reactions with selected milling agents and facilitating controlled incorporation of heteroatoms and functional groups. Such edge-focused functionalization provides an effective means of balancing electrical conductivity, wettability, ion accessibility, and electrochemical activity. This review critically examines the mechanistic principles governing graphite exfoliation during ball milling, the roles of milling agents and processing parameters in regulating structural evolution and surface chemistry, and the characterization strategies used to distinguish edge functionalization from basal-plane modification. Particular emphasis is placed on understanding the relationships between processing conditions, defect generation, functionalization pathways, and electrochemical performance. The influence of edge-engineered graphene on charge storage mechanisms in supercapacitors, lithium-ion batteries, sodium-ion batteries, zinc-ion systems, and hybrid energy-storage devices is comprehensively discussed. In addition, key considerations related to scalability, process economics, sustainability, contamination control, energy consumption, reproducibility, and industrial implementation are evaluated. Overall, this review establishes a process-structure-electrochemistry framework for shear-driven ball-milled graphene and highlights its potential as a scalable platform for the development of advanced graphene materials tailored for next-generation energy-storage technologies.
This study introduces the development of an innovative and environmentally friendly bio-nanocatalyst (CoFe2O4@CS-BAPT/CuII nanocomposite), designed and employed for three-component synthesis of 2-amino-3-cyano-4H-pyrans. Chitosan (CS) as a biodegradable polymer was functionalized with bis(2-aminopyridine)triazine (BAPT) moieties. Subsequently, CoFe2O4 magnetic nanoparticles (MNPs) were incorporated and copper ions were immobilized on the composite to form the final magnetic nanocomposite (CoFe2O4@CS-BAPT/CuII). Characterization techniques such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDX) analysis, vibrating sample magnetometry (VSM), inductively coupled plasma atomic emission spectroscopy (ICP-OES), dynamic light scattering (DLS), and zeta potential were used to analyze the nanocomposite structure. XRD analysis showed a near-amorphous structure after functionalizing CoFe2O4 with chitosan. FE-SEM images revealed uniform particles without aggregation, with an average size of 12-14 nm. TGA indicated thermal stability up to 300 °C. CoFe2O4@CS-BAPT/CuII was successfully used in the green synthesis of 2-amino-3-cyano-4H-pyrans with potential biological properties. The desired products were synthesized with high yields (83-95%) in short reaction times (20-45 minutes). Furthermore, the catalyst exhibited easy magnetic separation and good reusability, highlighting its potential as an efficient and sustainable heterogeneous catalyst. Key advantages of this approach include the use of an easily accessible bio-polymer, environmentally friendly catalytic protocols, a simplified and cost-effective synthesis process, clean reactions that generate no additional waste, and the reusable nature of the catalyst.
The influence of porosity and surface functionalization strategies on the biosensing performance of nanoporous anodic alumina rugate filters (NAA-RF) is systematically investigated using reflectometric interference spectroscopy (RIfS). Highly ordered NAA-RF...
Atomic layer deposition (ALD) of ZnO enables conformal nanoscale coating on cotton textiles, imparting multifunctional properties for high-performance and smart fabric applications. However, the influence of ALD processing temperature on...
The occurrence of Ibuprofen in surface and wastewater is an emerging environmental concern due to its incomplete removal in conventional water treatment systems. In this work, ZnO-based hybrid photocatalysts decorated...
Hydrostatic-pressure, external electric-field, and aluminium-composition-controlled magneto-optical response in the GaAs/Al λ Ga1-λ As nanostructure with asymmetrical Gaussian confinement, is investigated applying the projection-operator framework. The magneto-optical response is systematically probed via the optically detected magneto-phonon resonance (ODMPR) effect, including strength, shift, and full width at half maximum (FWHM) of the ODMPR peak induced by intersubband and intrasubband transitions for absorption and emission processes of LO-phonons. The results show that: (i) the magneto-optical response probed via the ODMPR effect can be effectively controlled through both external and structural parameters; (ii) the magneto-optical response induced by both the intrasubband and intersubband transitions is very sensitive to the hydrostatic pressure and aluminium composition, while only the intersubband transition is sensitive to the external electric field; (iii) among the intersubband transitions due to phonon absorption and emission, and intrasubband transitions due to phonon emission, the FWHM of GaAs/Al λ Ga1-λ As asymmetrical Gaussian potential heterostructures resulting from intersubband transitions with phonon absorption are the largest and the most sensitive to variations in hydrostatic-pressure, quantum system temperature, and aluminium-composition λ, followed by the intrasubband transition due to phonon emission, while the intersubband transition due to phonon emission is the smallest and the least sensitive; (iv) and the sensitivity of the magneto-optical response to external electric field, confinement potential depth and width of the GaAs/Al λ Ga1-λ As nanostructure under the influence of aluminium composition and hydrostatic pressure, is also shown in detail. Comprehensive characteristics of the magneto-optical response of the GaAs/Al λ Ga1-λ As nanostructure are provided in the Conclusions, which are useful for the application potential of optoelectronic devices.
Cesium lead halide perovskites are promising materials for light-emitting diodes (LEDs) due to their tunable band gaps, defect tolerance, and high photoluminescence quantum yields (PLQYs) with narrow emission widths. In particular, mixed-halide CsPb(Br/Cl)3 nanocrystals (NCs) are promising candidates for true-blue light emission. The properties of these materials are influenced by both their size and composition; however, research on the synthesis conditions related to these two factors is limited. In this work, we systematically investigate the influence of reaction temperature on the morphology and optical properties of CsPb(Br/Cl)3 NCs synthesized via a hot-injection method. Morphological transformations from nanoplatelets to monodisperse cubic NCs were observed with an increase in reaction temperature. Optical spectroscopy shows a progressive red shift in emission, accompanied by a reduction in the peak linewidth and the Stokes shift. Bandgap energies determined from Tauc analysis strongly correlate with the size of cubic-shaped particles, as described by the Brus quantum confinement model. These results demonstrate that reaction temperature provides an effective strategy for controlling dimensionality, morphology, and excitonic properties of CsPb(Br/Cl)3 NCs, offering a simple pathway to tailor blue-emitting perovskite nanomaterials for optoelectronic applications.
This study reports a facile, one-step, and additive-free ion-exchange synthesis for the controlled formation of zinc oxide (ZnO) and zinc hydroxide (ε-Zn(OH)2) nanoparticles under room-temperature conditions with remarkably fast phase formation (within 2 minutes). The primary novelty lies in utilizing ordinary tap water as a green solvent, and an active chemical parameter to dictate phase evolution, thereby eliminating distilled water usage and energy-intensive thermal calcination. Structural and morphological characterization via XRD and TEM revealed a precise temperature-driven (15-45 °C) phase selection, yielding elongated ε-Zn(OH)2 structures at 15 °C, pure ZnO nanorods at 24-32 °C, and pseudo-spherical ZnO (9 nm) with a specific surface area of 35.76 m2 g-1 at 45 °C. Application of these nanomaterials in photocatalysis demonstrated exceptional efficiency, achieving over 99.2% methylene blue degradation under natural sunlight and 77% under indoor UV-A light (6 W lamp) within 150 minutes. Tauc plot analysis revealed a defect-induced bandgap narrowing, (E g ≈ 3.21-3.27 eV vs. 3.27 eV for bulk ZnO), expanding its light-harvesting capacity into the solar spectrum. Crucially, kinetic and thermodynamic analyses correlated this performance with an anomalous negative apparent activation energy (E ap), revealing a non-Arrhenius regime governed by exothermic adsorption-desorption equilibria, typical of a Langmuir-Hinshelwood mechanism. Furthermore, post-reaction FTIR analysis confirmed the high structural stability and photocorrosion resistance of the catalysts. Overall, these findings highlight a highly sustainable, energy-efficient, and industrially scalable pathway for fabricating high-efficiency photocatalysts for environmental remediation.
Two-dimensional laminar membranes with precisely controlled nanochannels have attracted significant attention for overcoming the permeability selectivity trade-off in water purification. Among them, MXene-based membranes exhibit unique advantages arising from their hydrophilic surfaces, rich surface terminations, and tunable interlayer spacing. This review presents MXene synthesis routes, including direct and in situ etching, hydrothermal processing, and emerging green approaches, with emphasis on their influence on flake morphology, surface chemistry, and stacking behavior. Membrane fabrication strategies, such as vacuum-assisted filtration, mixed-matrix integration, and interlayer engineering, are analyzed to establish correlations between structural features and separation performance. Particular attention is given to transport mechanisms within MXene nanochannels, where size sieving, electrostatic interactions, and confined transport collectively govern ion and molecule selectivity. Recent advances in crosslinking and nanoparticle intercalation are highlighted for effectively suppressing swelling and stabilizing angstrom-scale channels under aqueous conditions. MXene membranes demonstrate high rejection efficiencies with enhanced water permeance and antifouling properties across desalination, heavy metal removal, and organic contaminant separation. The remaining challenges, including scalable fabrication, structural stability, and defect control, are discussed to guide future development toward practical membrane applications.
In recent years, covalent organic frameworks (COFs) have emerged as powerful heterogeneous catalysts. Notwithstanding, attainment of both crystallinity and stability of COF-based catalysts under harsh conditions is still challenging. Herein, an imine-linked COF has been transformed into an amine-linked COF via the reduction of imine linkages. Amine linkages, due to their stable and irreversible nature, were functionalized with sulfonic acid groups, A-COF/SO3H, as a highly active catalytic center. X-ray diffraction (XRD) analysis clearly shows that the crystallinity of COF after modification was preserved. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analyses revealed that A-COF/SO3H has a plate-like intergrown morphology. The porosity of A-COF/SO3H was investigated by N2 adsorption/desorption, indicating a mesoporous structure with a surface area of 93 m2 g-1. To explore the catalytic performance, A-COF/SO3H was used as an acidic heterogeneous catalyst for the preparation of pyrrole-2-ones. Excellent yield of products, short reaction times and easy work-up are some of the major preferences of this protocol. Moreover, A-COF/SO3H exhibited good heterogeneity engineering potential and was recovered and reused up to four consecutive cycles without significant loss of its performance.
In this work, we demonstrate that the fluorescence of aqueous graphene oxide (GO) suspensions is significantly quenched upon the introduction of silver ions (Ag+). The extent of quenching exhibits a clear dependence on both Ag+ concentration and interaction time. Comprehensive characterization using TEM, SEM, AFM, and UV-visible spectroscopy confirms that Ag+ ions undergo in situ reduction and subsequently deposit onto the GO surface. Altogether, GO was shown to drive the spontaneous reduction of silver ions to silver nanoparticles while providing a support structure for the particles to nucleate and grow. The reduction mechanism was attributed to galvanic displacement driven by the relative reduction potential difference between GO and silver. An ultraviolet photoelectron spectroscopy study was carried out on GO to support this hypothesis. Finally, the type of interaction between silver and GO was investigated using FT-IR and XPS studies. Both studies confirmed that the main point of interaction is through the hydroxyl moieties of GO. Based on the obtained data, three possible mechanisms for fluorescent quenching behaviour were presented. It's anticipated that GO would provide a convenient pathway for silver ion sensing and silver-based nanophotonic applications through the discussed interaction pathways.
The presumed chemical inertness of gold nanomaterials underpins their biomedical application, yet their structural fate within the oxidative milieu of innate immune cells remains uncharacterised. Here, we show that sustained engagement of two-dimensional gold nanosheets (AuNS) with primary human neutrophils over 14 days induces progressive crystalline domain disruption and sulfur incorporation within degraded regions, resolved by transmission and scanning electron microscopy with coupled energy-dispersive X-ray analysis. Pharmacological dissection using inhibitors of myeloperoxidase (4-aminobenzoic acid hydrazide, 4-ABAH), NADPH oxidase NOX1/4 (Setanaxib; GKT137831) and 1-methylpropyl 2-imidazolyl disulfide; thioredoxin-1 (PX12) demonstrates that degradation requires convergence of parallel oxidative routes (MPO/HOCl and Fenton-like) with Trx-1-mediated thiol capture of Au+ as Au-S-Trx. PX12 abolishes the diagnostic Au-S signature without restoring gold content, whereas simultaneous blockade of all three axes returns gold to near-pristine levels with near-complete nanosheet persistence. Transcriptional profiling further reveals coupling between oxidative burst activity and inflammatory signalling. These findings redefine the biological stability of gold nanostructures under physiologically relevant inflammatory conditions.
Precise detection of sentinel lymph node (SLN) metastasis is critical for accurate cancer staging and effective surgical navigation. In this study, we developed a high-performance magnetic resonance imaging (MRI)/near-infrared (NIR)-II fluorescence imaging nanoplatform by integrating the NIR dye IR820 and the gadolinium-based MRI contrast agent (GdL) into mesoporous silica nanoparticles (MSNs) using bovine serum albumin (BSA) as the functional component. This nanoplatform exhibits strong NIR-II fluorescence tail emission and high longitudinal relaxivity, enabling dual-modality imaging for the diagnosis of primary tumors and metastatic lymph nodes, as well as NIR-II fluorescence-guided surgery (FGS). Within this system, BSA not only serves as a structural stabilizer but also significantly enhances IR820 fluorescence emission and improves GdL relaxivity. Notably, two types of surface-functionalized MSNs, amine- and thiol-modified, were systematically compared, and the thiol-modified MSNs exhibited superior imaging performance, including a red-shifted absorption peak and markedly enhanced NIR-II fluorescence emission. In vitro and in vivo experiments confirmed that the dual-modality nanoprobe accumulated efficiently in tumors and SLNs, enabling high-sensitivity MRI localization and high-resolution NIR-II fluorescence imaging of metastatic lesions. Overall, this study presents a surface-engineering strategy to enhance the imaging performance of MRI/NIR-II nanoprobes, offering a promising approach for accurate diagnosis of lymph node metastasis and real-time FGS.
Magnetic hyperthermia (MH) using iron oxide nanoparticles (MNPs) is a promising cancer treatment strategy, yet its efficacy strongly depends on efficient intracellular nanoparticle delivery. Here, we compared two strategies to enhance MNP uptake by tumour cells: (i) increasing the administered MNP dose and (ii) applying a static magnetic field (MF) gradient to promote nanoparticle-cell interactions and increase availability at the cell surface. Human tumour cell lines, representing distinct challenges for nanoparticle internalisation due to differences in growth behaviour and cellular organisation, were first incubated with glucose-functionalised 11 nm MNPs under two-dimensional (2D) culture conditions to control and quantify intracellular uptake under each strategy. Cells with pre-internalised MNPs were then embedded in collagen-based three-dimensional (3D) tumour models, where MH was applied and therapeutic efficacy was evaluated by confocal microscopy and flow cytometry. While both strategies increased intracellular MNP levels, only MF-assisted internalisation resulted in effective MH-induced cytotoxicity under mild conditions across all tested cell lines. These findings indicate that antitumour MH efficacy is not solely determined by nanoparticle uptake, but also by the strategy used to enhance internalisation, revealing an additional layer of complexity for designing efficient MH protocols.
Imidacloprid (IMI), a widely used pesticide, poses significant environmental and health risks due to its toxicity to humans and aquatic life. Understanding its degradation behaviour is essential for developing effective remediation strategies. This study investigates the plasmon-enhanced photocatalytic degradation of IMI using copper oxide thin films decorated with gold nanoparticles (Cu x O/Au). Under UV-visible light, the incorporation of plasmonic Au in the Cu x O configuration enhances the photocatalytic activity by 36.6% compared to the pristine Cu x O film, with an overall degradation of more than 71%, which is maintained even after three repeated uses. Photoluminescence analysis provided evidence of reduced electron-hole recombination after the incorporation of Au, which was further validated by electrochemical analysis. The localized surface plasmon resonance (LSPR) and interband transition effects in Au-NPs increase the overall light absorption and concentration of charge carriers in the system. LC-MS analysis showed a decrease in the molecular ion signal of IMI and the appearance of several lower-m/z transformation-related ions, supporting the photocatalytic transformation of IMI.
This study systematically explores the synthesis and functionalization of iron oxide nanoparticles (IONPs) synthesized via thermal decomposition methods using three common precursors: iron( iii ) oleate, iron pentacarbonyl, and iron acetylacetonate.
Two-dimensional molybdenum disulfide nanoparticles were formed in graphite interlayers by sulfurization and reduction-sulfurization treatments of a molybdenum chloride-intercalated graphite compound (MoCl5-GIC). When MoCl5-GIC was treated at 623 or 823 K under a flowing mixed gas of hydrogen sulfide and hydrogen, molybdenum disulfide nanosheets (MoS2-GIC(i)) with a thickness of 1-2 layers and lateral dimensions extending over several hundred nanometers were obtained. In contrast, when MoCl5-GIC was first reduced at 873 K under a hydrogen flow and subsequently sulfurized at 823 K under a mixed gas of hydrogen sulfide and hydrogen, molybdenum disulfide clusters (MoS2-GIC(ii)) with lateral dimensions of several tens of nanometers and consisting of 4-5 stacked layers were formed in the graphite interlayers. MoS2-GIC(i) and MoS2-GIC(ii) exhibited comparable catalytic activities for the hydrogenation of naphthalene; however, in the hydrodesulfurization of dibenzothiophene, MoS2-GIC(ii) showed higher desulfurization selectivity.
