Appl. Nano, Volume 7, Issue 3 (September 2026) – 12 articles

Porous polymer nanocomposites incorporating metal oxide nanoparticles (SiO₂, ZrO₂, and TiO₂) were synthesized via the aza–Michael addition reaction of ethyleneamines with poly(ethylene glycol) diacrylate (PEGDA) under polymerization-induced phase-separation conditions. The resulting nanocomposites exhibited interconnected particulate morphologies with particle diameters ranging from less than 0.5 to 5.0 μm. Increasing the nanoparticle content led to a significant reduction in particle size, indicating that the nanoparticles influenced the phase-separation process and the development of the porous structure. Energy-dispersive X-ray spectroscopy confirmed the homogeneous distribution of nanoparticles throughout the polymer matrix. The refinement of the porous morphology increased the bulk density and consequently enhanced the Young’s modulus of the nanocomposites. In addition, porous nanocomposites containing SiO₂ nanoparticles exhibited distinct coloration when immersed in toluene owing to the Christiansen filter effect. The transmission wavelength shifted toward longer wavelengths with increasing SiO₂ content, which was attributed to a decrease in the effective refractive index of the porous nanocomposites. These results demonstrate that the incorporation of metal oxide nanoparticles provides an effective strategy for controlling the morphology, mechanical properties, and optical functionality of porous polymer nanocomposites. Full article

Hydrolates are aqueous co-products of aromatic-plant distillation whose composition and functionality differ from those of the corresponding essential oils. This critical review links botanical source, distillation conditions, chemical composition, quantitative biological performance, food or agricultural application, and readiness for nano-enabled formulation. Direct hydrolate studies show marked heterogeneity: reported antimicrobial performance ranges from minimum inhibitory concentrations of 5.69–500 μL mL⁻¹ to approximately 1–3.5 log reductions in food models, while antioxidant results depend strongly on the assay and reporting unit. Evidence in foods is most developed for fresh produce, seafood, dairy, meat, and beverages, but direct bakery validation remains a gap. Hydrolates offer aqueous compatibility and generally lower sensory intensity than essential oils, yet low active-compound concentrations, batch variability, microbiological susceptibility, and limited shelf stability restrict reproducible use. Among nano-enabled solutions, one direct lavender-hydrolate nanoemulsion study reported a diameter of 225.4 ± 3.2 nm and a polydispersity index of 0.098 ± 0.011, together with improved antibacterial activity; however, hydrolate-specific encapsulation efficiencies, release kinetics, long-term stability, food validation, and field trials are largely unreported. Liposomes, polymeric nanoparticles, nanogels, and active films therefore remain mostly transferable concepts supported by essential-oil, extract, or isolated-compound studies rather than established hydrolate technologies. Future work should use standardized production and quality markers, free-hydrolate and unloaded-carrier controls, realistic matrices, safety and non-target testing, scale-up analysis, and quantitative sustainability assessment. Hydrolates are promising sustainable phytochemical resources, but claims of nano-enabled advantage require direct comparative evidence. Full article

Burns injuries present critical health and care challenges and remain one of the leading causes of preventable morbidity globally. The pathophysiology of burns injuries combines barrier disruption, dysregulated inflammation and biofilm-driven polymicrobial infection. Zinc oxide nanoparticles (ZnO NP) offer unique, multi-functional capabilities of broad-spectrum antimicrobial, pro-regenerative zinc (II) ion sources and an intrinsic transducer that is piezoelectric, photoresponsive and pH-responsive. This paper presents a comprehensive review of ZnO NP for the treatment of skin burns injuries with a focus on its multifunctional nanotherapeutic and sensor-integrated platforms. A structured literature search of PubMed, Scopus, Web of Science, Embase and IEEE Xplore covering the period 2015 to 2025 was conducted to identify and consolidate relevant pre-clinical and clinical evidence on ZnO-based and sensor-integrated burn wound platforms. From the survey across hydrogels, electrospun nanofibers, films, sprays, and three-dimensional bio-printed constructs, it is established that ZnO formulations achieve 60–95% wound closure by day 14 versus 30–55% for untreated controls, with 3–7 log10 colony-forming-unit reductions and minimum inhibitory concentrations of 8–256 micrograms per millilitre against multidrug-resistant pathogens. Wound healing is driven by sustained Zn²⁺ release, reactive-oxygen-species-mediated bactericidal action, matrix-metalloproteinase-9 modulation, vascular-endothelial-growth-factor and hypoxia-inducible-factor-1-alpha angiogenesis, and nuclear-factor-kappa-B suppressed inflammation. Emerging closed-loop sensor-integrated dressings deliver real-time wound pH, temperature, and matrix-metalloproteinase-9 readout coupled to near-field-communication actuated on-demand zinc release. Clinical translation is affected by several factors such as dose-dependent cytotoxicity associated with excessive ROS generation or dissolution, limited standardisation of green-synthesis methodologies, batch-to-batch variability in nanoparticle physicochemical properties and limited clinical trial data. ZnO-based theranostic platforms hold practical clinical translation potentials provided reproducible GMP-scale synthesis, long-term biocompatibility validation and comprehensive regulatory classification is systematically addressed. Full article

Self-assembled artificial nanostructures, such as DNA origami, have attracted interest as templates for the placement of inorganic materials because their design enables the incorporation of binding sites for attaching nanocomponents with nanometer-scale precision. In this work, we introduce a lithographically defined window-array substrate as an addressable platform for dark-field spectroscopic studies of individual DNA-origami-templated metallic nanostructures. The pattern was designed using the Nanometer Pattern Generation System (NPGS) software and written by electron beam lithography (EBL) on a SiO_x/Si substrate. The role of the EBL pattern is to provide spatially separated measurement sites that facilitate the localization, selection, and optical interrogation of single-particle and dimer configurations. Metallic nanostructures created by the DNA origami technique, with programmable placement of spherical gold nanoparticles (Au NPs), are used here. The nanostructures are rectangular, measuring 70 nm × 90 nm, with an Au NP attached at one corner or at two opposite corners. These seed NPs are later enlarged by controlled coalescence via electroless silver deposition. Localized surface plasmon resonance (LSPR) studies by dark-field microscopy (DFM) are presented as a proof-of-concept application for evaluating the scattering response of individual silver-metalized nanoparticles and dimers. Full article

Photocatalytic water splitting has emerged as a promising strategy for sustainable hydrogen production using solar energy. In this work, we investigate the photocatalytic performance of the C₂N monolayer under O₂ and O₃ exposure. Upon adsorption on C₂N, both molecules form weakly interacting states, resulting in a metallic solution. However, after dissociation into atomic oxygen, the band gap of the oxidised monolayer increases relative to the pristine C₂N, indicating a strong hybridisation of the C-O bond. These oxidised configurations exhibit band-edge positions that span the water redox potential, thereby reducing the likelihood of charge recombination and enhancing their separation. Interestingly, the optical absorption spectra show a blue shift relative to the pristine sample and lie in the visible region. These findings highlight the potential of oxygen- and ozone-modified C₂N monolayers for applications in photocatalytic water splitting and sustainable hydrogen production. Full article

Dimethyl phthalate (DMP) is an environmental contaminant known for its endocrine-disrupting properties, and its removal poses a critical environmental challenge. In this paper, we present a theoretical study of the adsorption of the DMP molecule and its isomers on pristine and nitrogen-doped graphitic surfaces, which represent the pore walls of nanoporous activated carbon, using density functional theory (DFT) calculations. Detailed wavefunction analyses were performed to elucidate the nature of adsorption on the AC surfaces. Our results reveal that nitrogen doping improves phthalate adsorption in the following order: AC-Pristine < AC-NH₂ < AC-Graphitic-N < AC-Graphitic-2N. This enhancement arises from changes in charge distribution that introduce electrostatic interactions between the COOCH₃ groups of the molecules and nitrogen-doped atoms on the AC surface. This study provides mechanistic insights into DMP adsorption on nitrogen-doped AC and offers rational guidelines for designing efficient carbon-based adsorbents for the removal of phthalate esters from contaminated water and the environment. Full article

Altermagnets combine compensated magnetic order with momentum-dependent spin splitting, enabling Berry-curvature control without net magnetization. Here we investigate mechanically driven altermagnet–topological-insulator (AM/TI) interfaces in which periodic modulation of the crystalline phase selectively renormalizes the cycle-averaged interfacial exchange harmonics through exact Bessel-function averaging. The resulting harmonic-selective control introduces a new tuning parameter—the drive amplitude—that continuously reshapes the angular mass texture and enables re-entrant transitions between distinct topological sectors. Using continuum Berry-curvature calculations, we show that amplitude-controlled modulation of the twofold and fourfold exchange harmonics produces topological switching, Hall-conductivity suppression near Bessel zeros, and enhanced thermoelectric responses. Cyclic driving protocols further generate nontrivial winding trajectories in the experimentally accessible two-mass control plane, providing a geometric characterization of adiabatic modulation cycles through a winding invariant. To establish the topological character of the predicted phases, the continuum results are independently validated using compact Brillouin-zone lattice regularization, gauge-invariant Fukui–Hatsugai–Suzuki Chern-number calculations, and open-boundary ribbon spectra. The proposed mechanism operates in the adiabatic regime accessible to piezoelectric and surface-acoustic-wave actuation at MHz frequencies and is compatible with strain-tunable AM/TI heterostructures at cryogenic temperatures. These results identify mechanically driven AM/TI interfaces as a platform for programmable topological transport and harmonic-selective Berry-curvature engineering. Full article

Modern aquaculture is essential for meeting the increasing global demand for fish and seafood, but its rapid expansion has exposed limitations that threaten long-term sustainability. Major challenges include high disease outbreaks, low nutritional efficiency, and the instability and poor solubility of nutraceuticals and plant-derived compounds. These challenges often create a self-reinforcing feedback loop, amplifying the detrimental effects of one another. Conventional approaches, including antibiotics, chemical treatments, aquafeeds, and chemotherapeutic agents, have shown limited effectiveness, partly due to inefficient delivery systems that can contribute to environmental contamination and antimicrobial resistance. This review discusses nanotechnology-enabled strategies to improve these traditional methods, focusing on nanocarriers and nanoencapsulation techniques, and also mentioning other synthetized nanoparticles and microencapsulation strategies. These systems have succeeded in reducing oxidative degradation and improving bioavailability by enhancing the stability and activity of encapsulated bioactives. The review also evaluates their functional performance, limitations, environmental effects, interactions with different organisms, and regulatory constraints in the industry. Overall, while safe and scalable use of biodegradable nanoscale delivery systems in modern aquaculture has shown great potential, it still depends on careful design, harmonized regulations, and economically feasible manufacturing. Full article

Silicon carbide (SiC) is the leading wide-bandgap semiconductor material, providing mature doping and device fabrication. Additionally, SiC hosts a multitude of optically active point defects (color centers) and is relevant for many applications in quantum technologies. A crucial step towards harnessing the full potential of the SiC platform includes technologies to create color centers with defined localization and density, e.g., to facilitate their coupling to nano-photonic structures and to observe cooperative effects. Here, silicon vacancy centers and divacancies stand out, as no impurity atom is needed, and high-thermal budget annealing steps can be avoided. We characterize the effect of localized, femtosecond laser irradiation of SiC, investigating surface modifications and photoluminescence, including Raman spectroscopy and optical lifetime measurements. We employ commercial, high-purity, semi-insulating substrates and an industrial-grade laser system to explore broader applicability of the method. As a novel approach, we apply femtosecond laser irradiation to SiC substrates with an epitaxial graphene layer and find that the threshold for photoluminescence due to laser treatment is lowered. Full article

The present work analyzes light propagation in asymmetric waveguides with dielectric cores and anisotropic multilayer claddings based on nanometric planar hyperbolic metamaterials. A generalized definition of asymmetry, incorporating both structural and physical parameters, is introduced by varying metal composition and filling ratios in the claddings. The influence of wavelength, material permittivity, metal filling fraction, and core thickness on surface wave modes is examined using effective medium theory and considering experimentally derived material data. Propagation distances on the order of 400 µm have been achieved for optimized waveguide configurations operating within the C-band used in optical telecommunications. Full article

Supercapacitors are widely used in high-power-density applications due to their ability to deliver rapid energy bursts and fast recharging. The incorporation of naturally derived materials into supercapacitor electrodes offers notable advantages in terms of sustainability, environmental impact, and biodegradability relative to their synthetic counterparts. In this study, activated carbon with high electronic conductivity is combined with pyrolyzed sucrose as a binder to fabricate thin-film electrodes, with 2.50 mol dm⁻³ H₂SO₄ serving as the electrolyte. Both constituent materials are characterized with respect to their structural and electrical properties. The optimized electrodes exhibit a sheet resistance of 171.24 Ω sq⁻¹ and a resistivity of 1.92 × 10⁻⁴ Ω cm. The assembled electric double-layer capacitor achieves a specific capacitance of 74.35 F g⁻¹ at an activated carbon-to-sucrose ratio of 1:2, following sintering at 350 °C for 20 min. Cyclic voltammetry reveals capacitive-to-diffusive current contributions of 93:7% at 200 mV s⁻¹ and 67:33% at 5 mV s⁻¹, with a specific capacitance retention of 77% after 1000 cycles. Collectively, these results indicate that the fabricated electrodes possess satisfactory energy storage capability and adequate electrochemical stability. The findings suggest that biomass-derived activated carbon–pyrolyzed sucrose composites warrant consideration as cost-effective and environmentally benign electrode materials for sustainable energy storage applications. Full article

Hydrogen peroxide (H₂O₂) is a key reactive oxygen species involved in both cellular signaling and oxidative stress, making its reliable detection essential in biological and environmental systems. Electrochemical sensing has emerged as a promising approach for H₂O₂ monitoring due to its high sensitivity, rapid response, and suitability for in situ analysis. This review provides a comprehensive overview of nanostructured metal oxide electrodes for non-enzymatic electrochemical detection of H₂O₂. The effects of material composition, nanostructure morphology, and synthesis strategies (particularly hydrothermal methods) on sensor performance are critically discussed. Special attention is given to our previously reported studies, enabling a consistent comparison of structure–property relationships under similar experimental conditions. Furthermore, the application of these sensors in plant stress analysis is examined, including both the monitoring of oxidative stress and the evaluation of stress mitigation strategies using metal oxide nanoparticles. The role of nanoparticles as reactive oxygen species scavengers and enhancers of plant antioxidant systems is highlighted, demonstrating their ability to reduce H₂O₂ levels and improve plant physiological status under adverse environmental conditions. Overall, this work emphasizes the dual functionality of nanostructured materials as both sensing platforms and active agents for stress mitigation, highlighting their potential in agricultural and environmental applications. Full article