The integration of green nanotechnology with traditional medicinal plants offers a sustainable platform for designing multifunctional nanomaterials. In this study, we report the phytosynthesis of silver nanoparticles (AgNPs) using hydroethanolic extracts of Cecropia peltata L., a neotropical species endemic to the Ecuadorian Amazon and recognized for its ethnopharmacological relevance. The biosynthesized nanoparticles (Cp-AgNPs) were characterized using XRD, SEM, EDS, TEM, DLS, UV-Vis, and FTIR. Phytochemical analysis of the C. peltata extract revealed high contents of ferulic acid, p-hydroxybenzoic acid, and other flavonoids and phenolic acids, which could act as natural reducing and capping agents. The Cp-AgNPs exhibited potent and broad-spectrum antimicrobial activity against clinically relevant strains, with a minimum inhibitory concentration (MIC) of 6 µg/mL against Staphylococcus aureus and strong inhibition of multidrug-resistant (MDR) strains, including Pseudomonas aeruginosa and Enterococcus faecium, which represent urgent global health threats. Cp-AgNPs showed minimal hemolytic toxicity, underscoring their biocompatibility. These findings demonstrate that C. peltata L.-derived silver nanoparticles represent a green and promising alternative for the development of safe and efficient antimicrobial nanomaterials, particularly for applications in biomedicine and infection control. Furthermore, the work highlights the value of underexplored Amazonian flora as a source of bioactive compounds for the sustainable production of next-generation nanomaterials.

Apatites are the most common phosphate minerals with the general formula ^IXM1₂^VIIM2₃(^IVTO₄)₃X (Z = 2), where M = Ca²⁺, Pb²⁺, Ba²⁺, Mn²⁺, Sr²⁺, Na⁺, Ce³⁺, La³⁺, Y³⁺, Bi³⁺, REEs (rare earth elements); T = P⁵⁺, As⁵⁺, V⁵⁺, Si⁴⁺, S⁶⁺, B³⁺, and X = F^-, OH^-, Cl^-. The most frequently used synthetic apatite is carbonate fluorapatite (F-Ap) (Ca_10-xM_x(PO₄)_6-x(CO₃)_x(F₂), where M⁺ can be Na⁺, NH⁴⁺, or K⁺. Synthetic apatite has good compatibility with human bones and teeth and as such is used for the preparation of bone-substitute ceramics and dental implants that imitate the chemical composition of the natural hard tissue.

The ball milling activation (BMA) method is often used to increase the chemical activity of substances or as a solid-phase synthesis method. These effects are the result of the revelation of a fresh reaction surface, crystallite size reduction, and/or an increase in solid-state defects under the influence of accumulated mechanical energy during activation.

This work investigates the influence of BMA on the crystal-chemical properties of synthetic nano-fluorapatite activated for a period of 30 and 300 min with 20 mm diameter steel grinding bodies in a planetary ball mill. The changes in the F-Ap properties were analyzed by PXRD, FTIR, and WD-XRF.

It was established that the BMA process of synthetic nano-fluorapatite leads to changes that are important for its medical application: amorphization of F-Ap; reduction in the size of particles; increase in carbonate content; isomorphous transformations and solid-state synthesis with the formation of ortho- and pyrophosphates.

Acknowledgments: The authors gratefully acknowledge the financial support of Project No. BG-RRP-2.017-0032-C01 "Sustainable utilization of critical elements for environmental products based on phosphates, biomass and technogenic materials". The project is financed by the European Union-NextGenerationEU, through the National Recovery and Resilience Plan of the Republic of Bulgaria.

Conducting polymer–metal hybrid materials have emerged as advanced platforms for electrochemical biosensing due to their high electrical conductivity, tunable surface characteristics, and versatile functionalization capabilities. In this study, we report the electrosynthesis of polypyrrole–silver (PPy–Ag) hybrid interfaces on glassy carbon electrodes as a foundation for biosensor development. Polypyrrole films were prepared via chronoamperometry at 1.3 V for 10 s, forming a uniform conductive matrix. Subsequently, silver nanoparticles were electrodeposited onto the PPy layer using pulsed potentials at −0.50 V for 3–5 s in an Ag₂SO₄/KSCN electrolyte, enhancing surface conductivity and catalytic activity. The resulting hybrid interfaces were thoroughly characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS), confirming the successful incorporation and uniform distribution of silver nanoparticles within the polymer matrix.

For biosensing applications, the antibodies Ki-67 (a cancer proliferation marker) and VP2 (a viral capsid protein) were covalently immobilized onto the PPy–Ag surfaces via Ag–NH₂ coordination under mild phosphate buffer conditions (pH 7.3). Electrochemical analyses revealed a notable increase in conductivity after silver incorporation and a significant reduction in current response upon antibody binding. This behavior suggests effective surface passivation and stable bio-recognition layer formation. Overall, the PPy–Ag hybrid platform offers a reproducible and adaptable approach for the development of sensitive electrochemical immunosensors targeting both oncological and virological biomarkers.

Background: Pathological angiogenesis is a key driver of tumour progression and metastatic spread. Endogenous inhibitors of angiogenesis, including angiostatin and thrombospondin-related proteins, exhibit promising anti-tumour activity but are limited in clinical translation by poor stability and rapid systemic clearance. Biomacromolecular carriers represent a potential strategy to improve the pharmacological performance of protein-based anti-angiogenic therapies.

Methods: A protein-compatible nanoplatform based on human serum albumin was developed and evaluated as a carrier for anti-angiogenic proteins. The system was characterised in terms of physicochemical stability and protein–carrier interactions using standard analytical techniques. Cellular interaction and uptake were assessed in endothelial cell models. Systemic compatibility and short-term in vivo behaviour were evaluated in immunodeficient mice using circulating protein markers and indicators of oxidative stress.

Results: The albumin-based nanoplatform formed stable nanoscale assemblies with favourable physicochemical properties. Carrier–protein interactions supported efficient association of anti-angiogenic proteins and enabled controlled protein retention. In endothelial cell models, the nanoplatform enhanced cellular interaction compared to free proteins, without inducing excessive intracellular degradation. In vivo evaluation demonstrated prolonged systemic presence of albumin-associated formulations compared to unformulated proteins, with no detectable increase in systemic oxidative stress markers.

Conclusions: Albumin-based nanoplatforms offer a biocompatible and stable approach for improving the delivery of anti-angiogenic proteins. These findings support further development of albumin-mediated strategies for adjuvant anti-angiogenic cancer therapy.

Green hydrogen production has gained increasing attention in the past decade as the energy sector started to transition towards renewable energy sources and accelerated decarbonisation. As part of the X-Seed project, the principles of water electrolysis for hydrogen production were applied to develop a novel membrane-less electrolyzer operating under supercritical water conditions (above 374°C and 220 bar). Novel catalysts were synthesised as the first generation of electrodes tailored for supercritical water electrolysis.

Three perovskite-based nanofiber materials (SFM, PBCCF and LBCN) were synthesised using the electrospinning technique. Starting from polymeric precursor solutions, the materials were electrospun under optimized flow rates and voltages. A thermal treatment followed to remove the polymer and promote crystallization of the perovskite phase. The materials were characterized using XRD, ICP-MS, BET, and HR-SEM to evaluate their structural, compositional, and morphological features. Electrochemical characterization has been assessed first at normal temperature and pressure using HER and OER polarization curves up to 10 kA·m^-2. SFM exhibited the lowest HER overpotential (424 mV at 100 A·m⁻²) while PBCCF achieved an OER overpotential (443 mV at 10 mA·cm^-2) in 1M KOH. These results are promising for the application of perovskite-based nanofiber catalysts onto the selected electrode substrate for efficient hydrogen production under supercritical water conditions.

Acnowledgements

Project X-SEED with Grant Agreement number 101137701. The project is supported by the Clean Hydrogen Partnership and its members. Co-funded by the European Union. Views and opinions expressed are, however, those of the author(s) only and do not necessarily reflect those of the European Union or the Clean Hydrogen Partnership. Neither the European Union nor the granting authority can be held responsible for them.

Reference: X-SEED Project - Supercritical Hydrogen

Superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized via co-precipitation using FeCl₃·6H₂O, FeSO₄·7H₂O, and a 25% aqueous NH₄OH solution under ultrasonic and inert conditions. SPIONs were surface-functionalized with citric acid (CA) to enhance colloidal stability and dispersion. The modified SPIONs were incorporated into a 10wt.% poly(vinyl alcohol) (PVA) matrix to prepare a homogeneous solution. PVA/SPION fibers were then fabricated via electrospinning under the following conditions: voltage, 15kV, tip-to-collector distance, 12.5cm, and a feed rate, 0.5mL/h. The resulting nanofibers exhibited uniform morphology and distribution, suitable for biomedical and environmental applications.

Powder X-ray Diffraction confirmed average crystallite sizes of 25nm for all samples. Patterns of the samples show magnetite (Fe₃O₄) spinel structure at (111), (220), (311), (400), (422), (511), (440), and (533) planes, confirming preservation of crystallinity after CA functionalization and electrohydraulic treatment. FTIR Spectroscopy showed the disappearance of the free C=O band (1720cm⁻¹) and the emergence of COO⁻ stretching bands at 1558 and 1362cm⁻¹, proving the successful surface coordination of CA to the nanoparticle surface. Mössbauer indicated dominant magnetite with hyperfine fields, with - 47T, 42–44T, and a high-IS Fe(III) component confirming CA binding. DLS and zeta potential analysis revealed size reduction from ~186nm (Bare) to 70–106nm (CA-SPIONs) and charge reversal from +25mV to –52mV, ensuring colloidal stability. VSM confirmed superparamagnetic behavior with saturation magnetization values of 60.2emu/g for bare SPIONs, 51emu/g -CA-SPIONs, and 59emu/g -CA-SPIONs after electrohydraulic treatment. Raman spectroscopy revealed a mixed magnetite–maghemite phase in CA-SPIONs, enhancing the A₁g Fe–O band and preventing oxidation. The Fe-O signal persisted after embedding in PVA nanofibers, confirming stable incorporation and preservation of magnetic structure. SEM analysis revealed that the nanofibers ranged between 200 and 400nm in diameter, with a 310nm mean and 270nm median value.

These superparamagnetic nanofiber composites, characterized by nanoscale dimensions, superparamagnetic behavior, and surface stability, are suitable for biomedical applications, targeted drug delivery, hyperthermia treatments, and tissue engineering scaffolds.

Lignin, an abundant biopolymer recovered from agro-forestry waste streams, exhibits intrinsic redox and chelating properties that enable the reduction of metal salts into nanoparticles (NPs) and the adsorption/stabilisation of the resulting nanostructures. These features make lignin-derived nanoparticles (LNPs) an attractive, low-cost functional component for hybrid nanomaterials and sensing platforms. In this work, we investigate electrospun nanofibres functionalised with LNPs as active concentrators of gold nanoparticles (AuNPs). LNPs extracted from agro-forestry by-products were embedded into polymer nanofibres, providing phenolic and quinone-like groups capable of reducing Au(III) precursors and immobilising the resulting AuNPs. By adjusting the pH of the gold salt solution and the chemical environment around the LNPs, we achieve selective, rational decoration of the nanofibres with AuNPs without external reducing agents. This strategy also enables the recovery of AuNPs from RAEE-derived (electronic-waste) leachates, offering a sustainable route for metal reclamation and upcycling into functional materials. SEM/TEM analysis confirms controlled AuNP nucleation and growth on the fibre surface, while electrical measurements show that AuNP loading increases nanofibre conductivity of about three orders of magnitude through improved charge-transport pathways. Preliminary gas-sensing tests toward polar VOCs reveal enhanced signal amplitude and tuneable selectivity, attributed to synergistic interactions between lignin functional groups, AuNP surface chemistry and the polymer matrix. Overall, this study demonstrates a bio-based, low-cost and sustainable materials platform in which lignin nanoparticles act simultaneously as redox agents, metal concentrators and functional dopants, enabling new hybrid nanofibrous architectures for sensing and resource recovery.

In recent years, chemical and biological sensing using plasmonic nanostructures has gained significant attention due to their ability to detect a wide range of small chemical molecules, from biomarkers to narcotics. The primary appeal of the surface plasmon resonance (SPR) technique lies in the induction of a polariton at the metal–insulator interface under coupled conditions, which manifests as a distinct intensity minimum in reflectance spectra. In this study, a Cu/Ta₂O₅/Cu MIM-based nanostructure is proposed as a means to produce well-defined (narrow and deep) plasmonic responses that experience pronounced angular shifts when the surrounding dielectric environment changes. In other words, this enables the development of a precise thin-film-based chemical compound detection system. The approach relies on amplifying the near-field interaction between adjacent metal films by incorporating a high-optical-density dielectric layer only a few nanometers thick. Finite-element numerical simulations were used to guide the geometric optimization of the nanostructures, yielding optimal MIM dimensions of 20/5/20 nm, and the resulting systems were deposited at room temperature via non-reactive RF magnetron sputtering using an Intercovamex S16 system. Experimental validation was performed using angular interrogation in the Kretschmann configuration with a 633 nm light source.

The morphology of metal nanoparticles has long since been known to significantly influence their physiochemical properties, with nanoscale chirality and nanoparticle size being identified as two areas of significant interest. Gold nanoparticles (AuNPs) in particular have been noted for their interactions with chiral molecules, and have since become an active area of research to better understand chirality transfer, enantiomeric selectivity, and molecular binding mechanisms at the nanoscale. Here, the effects of AuNP size on chiral interactions with amino acids, specifically cysteine, are explored by utilising both Density Functional Theory (DFT) calculations and Molecular Dynamics (MD) simulations, with a particular emphasis on size-dependent changes in enantioselective adsorption behaviour. Previous studies identify the Au-thiol bond as a root cause of chirality transfer, and have stated that nanoparticle size and surface structure heavily influence the binding orientation and subsequent stability of adsorbed cysteine enantiomers. The interactions of sub-10nm AuNPs with chiral cysteine molecules using reactive MD models are examined to determine how size-dependent structural changes influence enantioselective binding and adsorption modes, revealing significant differences in adsorption behaviour across the size range studied. Through this multiscale MD and DFT approach, we provide new insights into enantiomeric binding preferences and size-dependent chiral interactions and demonstrate how nanoparticle size can act as a tuneable parameter for enantioselective applications, including nanoscale catalysis and biosensing.

Amine-functionalized zirconium-based metal–organic frameworks are promising materials for selective water purification due to their highly tunable porosity and functional surface chemistry. In this work, UiO-66-NH₂ samples were synthesized at different temperatures (45–120 °C) and systematically characterized to elucidate their structure–property relationships. X-ray diffraction confirmed the formation of a highly crystalline cubic UiO-66 framework, consistent with the reference Zr–UiO-66 structure, with crystallite sizes in the range of ~24–35 nm. Nitrogen adsorption–desorption measurements confirmed a predominantly micro/mesoporous texture with a high specific surface area, which was suitable for fast mass transfer and adsorption processes. The adsorption performance of UiO-66-NH₂ was evaluated using real groundwater samples containing total 96 μg/L total arsenic. Comprehensive chemical analysis of water before and after treatment revealed a pronounced selectivity of UiO-66-NH₂ toward harmful oxoanions. Batch adsorption experiments demonstrated exceptionally fast kinetics, with arsenic concentrations reduced by more than one order of magnitude within ~10 minutes, achieving final levels well below the World Health Organization guideline value of 10 ppb. Alongside arsenic, phosphate was efficiently removed (97–99%), while the concentrations of dominant macroelements (Na⁺, K⁺) remained unchanged and only mild Ca²⁺/Mg²⁺ reduction was observed. Kinetic modeling suggests rapid surface-controlled adsorption driven by strong interactions between arsenic species and the amino-functionalized zirconium sites through electrostatic attraction, hydrogen bonding, and surface complexation.

Acknowledgement

This research was supported by the Ministry of Science, Technological Development and Innovation of the Republic of Serbia and the Ministry of Education, Science and Innovation of Montenegro, within the framework of the EUREKA project “Design and Development of Eco-Friendly Filter Media for Safe Drinking Water” (Acronym: SAFEDRINK).