Carbon dots (CDs), a class of fluorescent nanomaterials, have emerged as powerful tools for biological applications, particularly in the targeting, imaging, and therapeutic modulation of mitochondria. Due to their small size, simplicity of synthesis, biocompatibility, and tunable optical properties, CDs can be engineered to selectively accumulate in mitochondria, enabling real-time imaging of mitochondrial function and dynamics in live cells. Moreover, their ability to carry therapeutic agents, such as antioxidants, drugs, and gene delivery vectors, offers potential in treating mitochondrial dysfunction, which is central to various diseases, including neurodegenerative disorders, cancer, and metabolic diseases. Recent advancements in surface functionalization have enhanced mitochondrial targeting and specificity, while ongoing research aims to optimize the safety, efficiency, and clinical translation of CDs for therapeutic applications. This review highlights the latest developments in the use of carbon dots for mitochondrial imaging, therapeutic delivery, and disease intervention, offering promising avenues for future research and clinical applications.

Nanomaterial-mediated photothermal therapy is an emerging approach to cancer care; however, the required biocompatibility of nanoparticles remains a critical aspect. To enhance their biocompatibility, biocompatible sources can be used in nanoparticle preparation instead of the conventional toxic substances that are generally required. To this end, grape marc, obtained as agricultural waste from the winery industry, was chosen as an important source of natural compounds. By modifying the nanoparticle surface, it can form a crucial interface with the surrounding environment. In this work, green gold nanoparticles were synthesized and applied in photothermal therapy, and their biocompatibility, antitumor, and antibacterial properties were evaluated. Reducing sugars and polyphenolic compounds, naturally occurring in grape marc waste, were extracted in water and successfully employed in the preparation of gold nanoparticles, as confirmed by the appearance of a plasmonic band at 535 nm. A second peak at 286 nm, typical of phenolic groups, demonstrated the presence of a polyphenolic layer on the nanoparticle surface, which was also confirmed in FTIR studies. TEM and XRD analyses revealed their crystalline nature, with an average diameter of about 30 nm. A third absorption peak in the near-infrared region (750 nm) shows that the synthesized gold nanoparticles can be good photothermal agents with a temperature increase of about 22 °C after 10 minutes of NIR laser irradiation (808 nm and 1.7 W cm-2). Good biocompatibility with human fibroblasts and breast cancer cells (MCF-7) was also demonstrated at high concentrations (400 µg mL-1), with the cell viability remaining above 70% during 72 hours of incubation. Antibacterial and antitumoral effects of the synthesized nanoparticles were observed after NIR laser irradiation, with 41.7% and 52.5% cell viability inhibition in S. aureus and E. coli, respectively, at higher concentrations, and a reduction of MCF-7 cell viability to 37%.

A biocompatible dispersion of carbon dots (CDs) has been obtained by laser irradiation of graphene oxide (GO) placed in liquids. The CDs synthesis uses a pulsed IR laser operating at 970 nm, 100 ms pulse duration, and 1.1 kJ/cm 2 fluence. The carbon target is constituted by GO sheets, containing micrometric GO flakes, immersed in a common phosphate-buffered saline (PBS) solution used in biology. CDs are functionalized by the solution salts and, under UV excitation, produce a high-intensity dispersion luminescence in the visible region. The optical properties and other physical characteristics of the dispersions are presented. The CD's fluorescent emission occurs in the blue region, around 478 nm, upon excitation at 365 nm. The synthesized CDs showed high biocompatibility, stability, and nontoxicity. This study provides an inexpensive and simple method for synthesizing biocompatible CDs in liquids for useful applications in bioimaging, diagnostics, and therapy.

This study investigates the ultra-fast photocatalytic degradation of methylene blue (MB) using a mixed-phase titanium dioxide (TiO2) nanopowder synthesized via a sol-gel method followed by dehydration and calcination at 450 degrees C for 2 h. The resulting TiO2 exhibits a biphasic structure composed of 87.4% anatase and 12.6% brookite, confirmed by X-ray diffraction (XRD), Rietveld refinement, and high-resolution transmission electron microscopy (HR-TEM). TEM analysis reveals the nanoparticles are predominantly spherical with an average particle size of 18.5 nm and a standard deviation of 4.6 nm. Under UV light irradiation at 366 nm, the synergistic interaction between the two crystalline phases enhances charge separation and facilitates rapid generation of reactive oxygen species (ROS), enabling complete MB degradation within 1 min, the fastest rate reported so far for mixed-phase TiO2. Notably, the nanopowder exhibits high operational reusability, retaining its photocatalytic performance for at least 30 consecutive cycles with persistent degradation efficiency in each cycle. These results highlight the critical role of phase composition and nanostructure optimization in the design of TiO2 photocatalysts for robust and sustainable environmental remediation, particularly in dye-polluted water treatment.

The advent of graphene has catalyzed extensive exploration into two-dimensional (2D) materials, among which gallium selenide (GaSe)—a layered semiconductor—stands out for its promise in optoelectronic and nanoscale device applications. To elucidate the intricate correlation between structure and electronic properties, and to enable performance optimization at the atomic scale, we employ advanced characterization methodologies. In this work, atomic-resolution Scanning Transmission Electron Microscopy (STEM) and Electron Energy Loss Spectroscopy (EELS) are utilized to investigate the structural and electronic characteristics of GaSe. STEM imaging confirms the atomic-level uniformity and verifies the β-GaSe phase, while EELS measurements reveal a thickness-dependent, tunable bandgap that decreases from 3.8 eV to 2.4 eV as the crystal thickness increases from approximately 1 nm to 30 nm—a trend attributable to quantum confinement effects.

The demand for a “green” approach to the synthesis of nanomaterials is becoming increasingly pressing. In response to this need, we present, for the first time, the use of spark ablation as an environmentally friendly deposition technique to obtain nanoparticles of copper nitride, a material that is gaining increasing attention in the field of photovoltaic advanced technologies. This method involves the ablation of pure copper electrodes in nitrogen atmosphere while a spark current is tuned. The overall result is the co-presence of nitride and oxide nanoparticle agglomerates with different sizes according to the spark current, as confirmed by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and energy-dispersive spectroscopy techniques. Scanning probe microscopy and scanning electron microscopy show an increase in the number and size of nanoparticle agglomerates with an increasing current, while the nanoparticle size is always about sub-10 nm. The findings of this work promote spark ablation as a simple, versatile, cost-effective, environmentally friendly deposition method to obtain nitride-based nanoparticles. Furthermore, it is compatible with many types of materials and substrates, increasing the possible combinations of metals/semiconductors and carrier gas types to obtain completely innovative materials with unique compositions and properties.

Nanometric Carbon dots (CDs) were synthesized using the laser ablation of vegetable carbon placed in a liquid. A pulsed diode laser operating at a 970 nm wavelength was employed to irradiate a charcoal target placed in a phosphate-buffered saline (PBS) solution with neutral pH. The laser radiation induces carbon ablation and exfoliation, with an ablation yield of the order of 5 ng/laser pulse. Small carbon dots and larger carbon nanoparticles were synthesized in the solution. A 365 nm UV lamp irradiation of the CDs dispersion induces visible luminescence emission at about 478 nm wavelength, with a typical blue-green color. UV-Visible-NIR and FTIR spectroscopies have permitted to evaluation of the dispersion liquid transmittance and absorbance. TEM microscopy has evinced that the synthesized CDs are crystalline with a spherical shape and an average size of the order of 1.5 nm. The CD's properties in terms of luminescence and quantum yield in the biocompatible dispersion are presented and discussed for advanced possible applications to the biological and medical fields.

Lead halide perovskite nanocrystals (NCs), such as CsPbBr3, are promising candidates for next-generation scintillators due to their ultrafast radiative kinetics and high emission efficiency. However, their integration in composite scintillators is limited by poor compatibility with high-Z sensitizers, reabsorption losses at high loading, and low radiation stopping power due to their nanoscale dimensions. Here, a robust strategy is demonstrated to hybridize CsPbBr3 NCs with hafnium oxide (HfO2) nanoparticles (NPs) as transparent, high-Z electromagnetic sensitizers. Surface oxygen dangling bonds on HfO2 NPs are identified as the main source of perovskite degradation and it is shown that a PbBr2 pre-treatment effectively passivates these sites. This enables stable NC-NP hybrids, preserving optical quality and scintillation properties. Co-synthesis in the presence of treated HfO2 NPs suppresses NC degradation and enhances both photoluminescence efficiency and thermal robustness. The hybrids can be embedded in polymer nanocomposites via thermal radical polymerization, a process typically detrimental to perovskites. Under X-ray excitation, HfO2 NPs significantly enhance radioluminescence intensity without compromising the ultrafast response of CsPbBr3 NCs, confirming efficient electromagnetic sensitization via electron cascade. This work offers a viable pathway for designing hybrid nanoscintillators with enhanced stopping power and stable optical performance for practical radiation detection technologies.

Lead halide perovskite nanocrystals (LHP-NCs) embedded in a plastic matrix are highly promising for a variety of photonic technologies and are quickly gaining attention as ultrafast, radiation-resistant nanoscintillators for radiation detection. However, advancements in LHP-NC-based photonics are hindered by their well-known thermal instability, which makes them unsuitable for industrial thermally activated mass polymerization processes - crucial for creating polystyrene-based scintillating nanocomposites. In this study, we address this challenge by presenting the first thermal nanocomposite scintillators made from CsPbBr3 NCs passivated with fluorinated ligands that remain attached to the particles surfaces even at high temperatures, enabling their integration into mass-cured polyvinyl toluene without compromising optical properties. Consequently, these nanocomposites demonstrate scintillation light yields reaching 10,400 photons/MeV, sub-nanosecond scintillation kinetics, and remarkable radiation resilience, able to withstand gamma radiation doses of up to 1 MGy. This performance not only meets but also exceeds the scintillation of plastic scintillators, despite the radiation-induced damage to the host matrix.

Lead halide perovskite nanocrystals (LHP-NCs) embedded in a plastic matrix are highly promising for a variety of photonic technologies and are quickly gaining attention as ultrafast, radiation-resistant nanoscintillators for radiation detection. However, advancements in LHP-NC-based photonics are hindered by their well-known thermal instability, which makes them unsuitable for industrial thermally activated mass polymerization processes, crucial for creating polystyrene-based scintillating nanocomposites. In this study, we address this challenge by presenting the first thermal nanocomposite scintillators made from CsPbBr3 NCs passivated with fluorinated ligands that remain attached to the particles surfaces even at high temperatures, enabling their integration into mass-cured polyvinyl toluene without compromising optical properties. Consequently, these nanocomposites demonstrate scintillation light yields reaching 10 400 photons/MeV, subnanosecond scintillation kinetics, and remarkable radiation resilience, able to withstand gamma radiation doses of up to 1 MGy. This performance not only meets but also exceeds the scintillation of plastic scintillators despite the radiation-induced damage to the host matrix.

Within the framework of the FTM-NEXT INFN (Fast Time Micropattern gaseous detectors - next of Nuclear Physics National Institute) experiment, we produced hydrogen-free diamond-like carbon films through pulsed-laser deposition to serve as resistive layers in modern resistive micro-pattern gaseous detectors that must work in extreme radiation environments at future colliders. To obtain homogeneous diamond-like carbon coatings, over medium-to-large size (3 cm x 3 cm), with excellent adhesion to the substrate and with typical surface resistivity values in the range of 1-100 MOhm/sq, growth conditions had to be optimized. In this paper we report on the stability of resistive diamond-like carbon layers subjected to increasing doses of irradiation with proton beams accelerated to an energy of 2 MeV. The morphological, structural, and electrical properties, also at the nanoscale level, of diamond-like carbon coatings following ion irradiation were studied by electron microscopy, electron diffraction, electrical transport characterization and scanning tunneling spectroscopy.

Magnetic nanocomposites (MNC) are promising theranostic platforms with tunable physicochemical properties allowing for remote drug delivery and multimodal imaging. Here, we developed doxorubicin-loaded Fe3O4-Au MNC (DOX-MNC) using electron beam physical vapor deposition (EB-PVD) in combination with magneto-mechanochemical synthesis to assess their antitumor effect on Walker-256 carcinosarcoma under the influence of a constant magnetic (CMF) and electromagnetic field (EMF) by comparing tumor growth kinetics, magnetic resonance imaging (MRI) scans and electron spin resonance (ESR) spectra. Transmission (TEM) and scanning electron microscopy (SEM) confirmed the formation of spherical magnetite nanoparticles with a discontinuous gold coating that did not significantly affect the ferromagnetic properties of MNC, as measured by vibrating-sample magnetometry (VSM). Tumor-bearing animals were divided into the control (no treatment), conventional doxorubicin (DOX), DOX-MNC and DOX-MNC + CMF + EMF groups. DOX-MNC + CMF + EMF resulted in 14% and 16% inhibition of tumor growth kinetics as compared with DOX and DOX-MNC, respectively. MRI visualization showed more substantial tumor necrotic changes after the combined treatment. Quantitative analysis of T-2-weighted (T2W) images revealed the lowest value of skewness and a significant increase in tumor intensity in response to DOX-MNC + CMF + EMF as compared with the control (1.4 times), DOX (1.6 times) and DOX-MNC (1.8 times) groups. In addition, the lowest level of nitric oxide determined by ESR was found in DOX-MNC + CMF + EMF tumors, which was close to that of the muscle tissue in the contralateral limb. We propose that the reason for the relationship between the observed changes in MRI and ESR is the hyperfine interaction of nuclear and electron spins in mitochondria, as a source of free radical production. Therefore, these results point to the use of EB-PVD and magneto-mechanochemically synthesized Fe3O4-Au MNC loaded with DOX as a potential candidate for cancer magnetic nanotheranostic applications.

Silver nanoparticles (AgNPs) have emerged as promising antimicrobial agents due to their unique properties and broad-spectrum antimicrobial action. However, their interaction with hydrogen peroxide (H2O2) in the bloodstream can lead to their oxidation, thereby reducing their antimicrobial effectiveness and potentially posing threats to human health. This study presents a novel approach to enhance the oxidation resistance of AgNPs by integrating them with carbon dots (CDs) to form an AgNPs/CDs hybrid system. CDs, with their exceptional biocompatibility and functionalized surface, can interact with AgNPs to provide a protective layer. Our green synthesis method employed microwave-assisted techniques using only three reagents: silver nitrate, l-tryptophan, and glucose. The characterization of the hybrid system was conducted using Ultraviolet–Visible spectroscopy (UV/Vis), Transmission Electron Microscopy (TEM), High Resolution TEM (HRTEM), and Finite Element Analysis (FEA). UV/Vis spectroscopy revealed a red shift in the absorption peak of the hybrid system compared to pure AgNPs, confirming the interaction between CDs and AgNPs. TEM and HRTEM analyses, supported by the PASAD plug-in and Image Pro‐Plus software, respectively, elucidated the structural arrangement and interaction of these nanoparticles. Additionally, FEA computations using FreeFEM software platform forecasted the resonant wavelengths.

Boron nanoparticles (BNPs) are attractive nanomaterials for their employment in many applications, such as neutron detection, boron neutron capture therapy, proton boron capture therapy and nuclear fusion. Depending on the specific application, 10B or 11B isotopes can be used. Nevertheless, there are significant challenges in developing suitable BNPs using both conventional chemical synthesis routes and dry fabrication techniques. In this study we report BNPs directly synthetised in water by pulsed Laser Ablation in Liquid (PLAL). Nanoparticles of elemental boron have been generated by laser ablation of a sintered 10B target in MilliQ water by employing ns laser pulse. The ablation resulted in BNPs and boron target micro-fragments with hydrogen gas and boric acid as by-products. Simple washing steps were used to obtain clean BNPs in water. The BNPs showed a narrow size distribution between 3 and 4 nm and their stability in water was induced by a thin layer of boron oxide surrounds BNPs. The BNPs were fully characterized by the chemical and structural point of view employing several techniques. A discussion on boron chemical reactions during laser ablation in water and after the NPs were released in solution was done.

AbstractOne of the physical methods for obtaining magnetite nanoparticles (NPs) is electron beam physical vapor deposition (EB PVD), which requires complex equipment, but allows obtaining a significant amount of pure (ligand-free) NPs. The biomedical application of such NPs is less studied than materials from other synthesis methods. The objective is to study the effect of pure magnetite NPs in the NaCl matrix obtained by EB PVD on hematological indicators, gases, electrolytes and parameters of iron metabolism in the blood of intact animals. The physical characteristics of NPs were studied using high-resolution transmission electron microscopy, scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy mapping, electron energy-loss spectroscopy, selected area electron diffraction and fast Fourier transform. In vivo experiments were conducted on albino male rats, which were injected with solution of magnetite-sodium chloride NPs (1.35 mg Fe/kg). After 3 and 72 h, hematological parameters, blood gases, electrolytes, and serum iron were determined. The synthesized NPs had an average size of 11 nm. They were identified as magnetite, where polycrystals and single crystals were present. The absence of contamination in crystal boundaries, clear orientation and orderliness of atoms in crystals were established. The administration of NPs in the sodium chloride matrix to animals was characterized by a transient increase in the main indicators of red blood accompanied by an increase in the saturation of erythrocytes with hemoglobin and their mean volume after 3 h. It did not worsen blood gases and pH, but decreased blood Na+ content after 72 h. The investigated NPs caused changes in the parameters of serum iron characteristic to iron preparations, which after 3 h were smaller compared to the reference iron drug, and after 72 h—similar to it. More intense rapid effects on hematological parameters at lower serum iron indicate greater activity of the studied pure magnetite NPs obtained by EB PVD syntesis compared to the reference iron preparation.

In recent times, the searches for alternative materials to plastic is a popular topic, due to the danger that synthetic materials cause to the environment and humans. Among the promising natural polymers, chitosan (CS) is certainly one of the most suitable since it it is edible, non-toxic and derives from crustacean waste.- However, it is necessary to improve its physical properties to be widely applied in food packaging, whose market is dominated by synthetic plastic. In this work we have synthesized silver nanoparticles (AgNPs) using hot-plate and microwaves-based techniques, using Aloe Vera leaves extracts. The synthetic process follows the principles of green chemistry, since no toxic substance is used to obtain nanomaterials. These NPs, having dimensions <20 nm, were characterized by TEM, zeta potential, UV-vis, FTIR, and then added to CS having low and medium molecular weight to develop thin films after its polymerization. These films were evaluated in terms of swelling ratio, optical properties, thermal stability, wettability, roughness, and friction coefficient, understanding that the physical properties of the films improved after the intercalation of the AgNPs, albeit differences were observed using the two NPs type. Subsequently, the release of silver ions from films using different pH as well as in vitro toxicity tests were carried out to evaluate their applicability. Largely, the excellent properties of new com- posite materials make them promising materials for packaging of different kinds of foods.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Herein, a study on the photocatalysis and antibacterial performances of Cu‐doped titania films as a function of the dopant concentration is presented. The TiO 2 films are produced by sol–gel spin‐coating technique, and the doping is performed by adding different quantities of copper in the form of salt (CuSO 4 ) during the preparation of sol. The obtained films are characterized by Raman and X‐ray diffraction spectroscopies, atomic force microscopy, and Rutherford backscattering spectrometry, to investigate on the chemical–physical properties, the quality, the composition, and the thickness. The photocatalytic activity of the films is studied by measuring the degradation of methylene blue (MB) under UV light, while Staphylococcus aureus is chosen for microbiological testing. The results show a correlation between photocatalysis and antibactericity with a rise of these two activities with increasing dopant concentrations in the films up to a given point, beyond which structural defects are introduced, promoting electron–hole recombination.

Diamond-like carbon (DLC) is an attractive inexpensive alternative to diamond. The control of the C (sp(3))/C(sp(2)) ratio, influencing the material properties, is fundamental for its use in dedicated applications like, for example, the fabrication of a particular class of gas detectors for ionizing particles termed Micro-Pattern Gaseous Detectors (MPGDs). A deposition technique enabling control on the amount of C(sp(3)) hybridized bonds, hydrogen content and disorder is pulsed lased deposition (PLD). In this paper, we report on the preparation of hydrogen-free DLC films by nanosecond excimer laser-based ablation of a graphite target correlating the laser fluence with the electrical properties of the DLC films to be used as protective resistive layers in MPGD detectors. Moreover, unprecedented physical insight and discussion are provided about the critical aspects of both occurrence of a V-branched plume and its composition on the spatial distribution of C(sp(3)) bonds and film uniformity. Improvement strategies are demonstrated by comparing and discussing two classes of PLD experiments: ON-axis (coaxial plasma expansion axis and substrate symmetry axis) and OFF-axis (substrate-axis shifted with respect to the plume-axis and rotating substrate). Optimally working OFF-axis configuration conditions are shown to lead to fine tuning of resistivity and uniformity of composition of C(sp(3)) bonding over a few cm(2) extended areas. Sheet resistance (3.1 +/- 0.3) x 10(9) Omega/sq., corresponding to C(sp3) bonding concentration of similar to 86%, is reported in OFF-axis experiments at a fluence of 5.5 J/cm(2) onto kapton substrates which are used for the realization of MPGDs.

Copper nanoparticles (CuNPs) as well as those of other noble metals show unique features that are not observed in bulk copper. Despite the enormous potential of CuNPs, their use is limited by their susceptibility to oxidation during and after synthesis. Here, an innovative method based on wet synthesis protocol was developed to produce an aqueous colloidal solution of CuNPs capped with Tween® 60 (Polyoxyethylene sorbitan monostearate) capable of being stable and non-oxidised for several months. The CuNPs colloidal solution was tested for the detection of hydrogen peroxide (H2O2) showing a detection limit of 10–11 M. This result may provide the basis for the design of a rapid, practical, and easy-to-use colorimetric sensor to detect H2O2 in the future.

Restoration procedures of the polychrome terracotta relief "Madonna and Child" with papier-mache in-serts from a shrine in Piove di Sacco (Padova, orthern Italy) were assisted by analytical investigations, contributing to identify the chemical composition of the pigments, fractures and internal damages, addi-tions and retouchings, which strongly modified the original manufact. In particular, energy dispersive X-ray fluorescence, Raman spectroscopy and FT-IR spectroscopy were employed to determine the chemical composition of pigments on the original layer and on the over-paintings and to understand the artistic techniques. Moreover, X-ray planar radiography and computed tomography were used to understand the structure and its conservative state. Finally, the relief, stylistically dated to the 17th century, turned out to be a Renaissance terracotta artefact. The polychrome blue traces of lapis lazuli highlighted a valuable artwork and the resemblance with the style of Donatello and his apprentices have recently led to further studies, as an initial part of a larger research on polychrome terracotta in Veneto. (c) 2021 Elsevier Masson SAS. All rights reserved.