One-Pot Synthesis of Luminescent and Photothermal Carbon Boron-Nitride Quantum Dots Exhibiting Cell Damage Protective Effects.

Zero-dimensional boron nitride quantum dots (BNQDs) are arousing interest for their versatile optical, chemical, and biochemical properties. Introducing carbon contents in BNQDs nanostructures is a great challenge to modulate their physicochemical properties. Among the carbon moieties, phenolic groups have attracted attention for their biochemical properties and phenol-containing nanomaterials are showing great promise for biomedical applications. Herein, the first example of direct synthesis of water dispersible BNQDs exposing phenolic and carboxylic groups is presented. The carbon-BNQDs are prepared in a single-step by solvent-assisted reaction of urea with boronic reagents and are characterized by optical absorption, luminescence, Raman, Fourier transform infrared and NMR spectroscopy, X-ray photoelectron spectroscopy, dynamic light scattering, and atomic force microscopy. The carbon-BNQDs exhibit nanodimension, stability, high photothermal conversion efficiency, pH-responsive luminescence and Z-potential. The potential of the carbon-BNQDs to provide photothermal materials in solid by embedding in agarose substrate is successfully investigated. The carbon-BNQDs exhibit biocompatibility on colorectal adenocarcinoma cells (Caco-2) and protective effects from chemical and oxidative stress on Caco-2, osteosarcoma (MG-63), and microglial (HMC-3) cells. Amplicon mRNA-seq analyses for the expression of 56 genes involve in oxidative-stress and inflammation are performed to evaluate the molecular events responsible for the cell protective effects of the carbon-BNQDs.

Synthesis and Unique Behaviors of High-Purity HEA Nanoparticles Using Femtosecond Laser Ablation.

High-entropy alloys (HEAs) are a class of metal alloys consisting of four or more molar equal or near-equal elements. HEA nanomaterials have garnered significant interest due to their wide range of applications, such as electrocatalysis, welding, and brazing. Their unique multi-principle high-entropy effect allows for the tailoring of the alloy composition to facilitate specific electrochemical reactions. This study focuses on the synthesis of high-purity HEA nanoparticles using the method of femtosecond laser ablation synthesis in liquid. The use of ultrashort energy pulses in femtosecond lasers enables uniform ablation of materials at significantly lower power levels compared to longer pulse or continuous pulse lasers. We investigate how various femtosecond laser parameters affect the morphology, phase, and other characteristics of the synthesized nanoparticles. An innovative aspect of our solution is its ability to rapidly generate multi-component nanoparticles with a high fidelity as the input multi-component target material at a significant yielding rate. Our research thus focuses on a novel synthesis of high-entropy alloying CuCoMn1.75NiFe0.25 nanoparticles. We explore the characterization and unique properties of the nanoparticles and consider their electrocatalytic applications, including high power density aluminum air batteries, as well as their efficacy in the oxygen reduction reaction (ORR). Additionally, we report a unique nanowire fabrication phenomenon achieved through nanojoining. The findings from this study shed light on the potential of femtosecond laser ablation synthesis in liquid (FLASiL) as a promising technique for producing high-purity HEA nanoparticles.

Red light-triggerable nanohybrids of graphene oxide, gold nanoparticles and thermo-responsive polymers for combined photothermia and drug release effects.

The development of multifunctional nanohybrid systems for combined photo-induced hyperthermia and drug release is a challenging topic in the research of advanced materials for application in the biomedical field. Here, we report the first example of a three-component red-light-responsive nanosystem consisting of graphene oxide, gold nanoparticles and poly-N-isopropylacrylamide (GO-Au-PNM). The GO-Au-PNM nanostructures were characterized by spectroscopic techniques and atomic force microscopy. They exhibited photothermal conversion effects at various wavelengths, lower critical solution temperature (LCST) behaviour, and curcumin (Curc) loading capacity. The formation of GO-Au-PNM/Curc adducts and photothermally controlled drug release, triggered by red-light excitation (680 nm), were demonstrated using spectroscopic techniques. Drug-polymer interaction and drug-release mechanism were well supported by modelling simulation calculations. The cellular uptake of GO-Au-PNM/Curc was imaged by confocal laser scanning microscopy. In vitro experiments revealed the excellent biocompatibility of the GO-Au-PNM that did not affect the viability of human cells.

Chemical and Morphological Modifications Induced by Argon Plasma Treatments on Fluorinated Polybenzoxazole Films.

Fluorinated photodefinable polymers are widely employed as re-distribution layers in wafer-level packaging to produce microelectronic devices because of their suitable low dielectric constant and moisture absorption, high mechanical toughness, thermal conductivity and stability, and chemical inertness. Typically, fluorinated photodefinable polybenzoxazoles (F-PBOs) are the most used in this field. In the present work, we investigated by atomic force microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy the morphological and chemical modifications induced by Ar plasma treatments on F-PBO films. This process, used to remove surface contaminant species, as well as increase the polymeric surface roughness, to improve the adhesion to the other components during electronic packaging, is a crucial step during the manufacturing of some microelectronic devices. We found that argon plasma treatments determine the wanted drastic increase of the polymer surface roughness but, in the presence of a patterned silver layer on F-PBO, needed for the fabrication of electric contacts in microelectronic devices, also induce some unwanted formation of silver fluoride species.

Smartphone-Assisted Sensing of Trinitrotoluene by Optical Array.

Here we report the design and fabrication of an array-based sensor, containing functionalized Carbon Dots, Bodipy's and Naphthalimide probes, that shows high fluorescence emissions and sensitivity in the presence of low amounts of TNT explosive. In particular, we have fabricated the first sensor device based on an optical array for the detection of TNT in real samples by using a smartphone as detector. The possibility to use a common smartphone as detector leads to a prototype that can be also used in a real-life field application. The key benefit lies in the possibility of even a nonspecialist operator in the field to simply collect and send data (photos) to the trained artificial intelligence server for rapid diagnosis but also directly to the bomb disposal unit for expert evaluation. This new array sensor contains seven different fluorescent probes that are able to interact via noncovalent interactions with TNT. The interaction of each probe with TNT has been tested in solution by fluorescence titrations. The solid device has been tested in terms of selectivity and linearity toward TNT concentration. Tests performed with other explosives and other nitrogen-based analytes demonstrate the high selectivity for TNT molecules, thus supporting the reliability of this sensor. In addition, TNT can be detected in the range of 98 ng∼985 µg, with a clear different response of each probe to the different amounts of TNT.

Electro-Sorption of Hydrogen by Platinum, Palladium and Bimetallic Pt-Pd Nanoelectrode Arrays Synthesized by Pulsed Laser Ablation.

Sustainable and renewable production of hydrogen by water electrolysers is expected to be one of the most promising methods to satisfy the ever-growing demand for renewable energy production and storage. Hydrogen evolution reaction in alkaline electrolyte is still challenging due to its slow kinetic properties. This study proposes new nanoelectrode arrays for high Faradaic efficiency of the electro-sorption reaction of hydrogen in an alkaline electrolyte. A comparative study of the nanoelectrode arrays, consisting of platinum or palladium or bimetallic nanoparticles (NPs) Pt80Pd20 (wt.%), obtained by nanosecond pulsed laser ablation in aqueous environment, casted onto graphene paper, is proposed. The effects of thin films of perfluoro-sulfonic ionomer on the material morphology, nanoparticles dispersion, and electrochemical performance have been investigated. The NPs-GP systems have been characterized by field emission scanning electron microscopy, Rutherford backscattering spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, cyclic voltammetry, and galvanostatic charge-discharge cycles. Faradaic efficiency up to 86.6% and hydrogen storage capacity up to 6 wt.% have been obtained by the Pt-ionomer and Pd/Pt80Pd20 systems, respectively.

3D Printing Manufacturing of Polydimethyl-Siloxane/Zinc Oxide Micro-Optofluidic Device for Two-Phase Flows Control.

Tailored ZnO surface functionalization was performed inside a polydimethyl-siloxane (PDMS) microchannel of a micro-optofluidic device (mofd) to modulate its surface hydrophobicity to develop a method for fine tuning the fluid dynamics inside a microchannel. The wetting behavior of the surface is of particular importance if two different phases are used for system operations. Therefore, the fluid dynamic behavior of two immiscible fluids, (i) air-water and (ii) air-glycerol/water in PDMS mofds and ZnO-PDMS mofds was investigated by using different experimental conditions. The results showed that air-glycerol/water fluid was always faster than air-water flow, despite the microchannel treatment: however, in the presence of ZnO microstructures, the velocity of the air-glycerol/water fluid decreased compared with that observed for the air-water fluid. This behavior was associated with the strong ability of glycerol to create an H-bond network with the exposed surface of the zinc oxide microparticles. The results presented in this paper allow an understanding of the role of ZnO functionalization, which allows control of the microfluidic two-phase flow using different liquids that undergo different chemical interactions with the surface chemical terminations of the microchannel. This chemical approach is proposed as a control strategy that is easily adaptable for any embedded micro-device.

Synthesis, Characterization and Photocatalytic Behavior of SiO2 @nitrized-TiO2 Nanocomposites Obtained by a Straightforward Novel Approach.

We report on the facile synthesis of SiO2 @nitrized-TiO2 nanocomposite (NST) by calcination of TiO2 xerogel with OctaAmmonium POSS® (N-POSS; POSS=polyhedral oligomeric silsesquioxanes). The as-obtained nanoporous mixed oxide is constituted by uniformly distributed SiO2 and nitrized-TiO2 , where the silica component is present in an amorphous state and TiO2 in an anatase/rutile mixed phase (92.1 % vs. 7.9 %, respectively) with very small anatase crystallites (3.7 nm). The TiO2 lattice is nitrized both at interstitial and substitutional positions. NST features a negatively charged surface with a remarkable surface area (406 m2 g-1 ), endowed with special adsorption capabilities towards cationic dyes. Its photocatalytic behavior was tested by following the degradation of standard aqueous methylene blue and methyl orange solutions under UV and visible light irradiation, according to ISO 10678:2010. For comparison, analogous investigations were carried out on a silica-free N-TiO2 , obtained by using NH4 Cl as nitrogen source.

Systematic Characterization of Plasma-Etched Trenches on 4H-SiC Wafers.

Silicon carbide power semiconductors overcome some limitations of silicon chips, and therefore, SiC is an attractive candidate for next-generation power electronics. In addition, the number of possible vertical devices that can be obtained on a given surface using the trench technique is significantly larger than that attainable using a planar setup. Moreover, a SiC trench power metal oxide semiconductor field-effect transistor (power MOSFET) structure removes the junction field-effect transistor (JFET) region (that would decrease the current flow width) and improves the channel density, thus reducing the specific electrical resistance. Consequently, in the present study, we report on the chemical bonding state of elements and structural characterization of trenches, obtained using SF6-based plasma etching, on the 4H-SiC polytype substrate. An interferometric algorithm that finds the endpoint to stop etching governed the trench depth. Scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy analyses stated the high quality and uniformity of the trenches. These materials are particularly promising for the fabrication of the SiC MOSFET to be implemented in the manufacturing of power devices.

Eco-Friendly 1,3-Dipolar Cycloaddition Reactions on Graphene Quantum Dots in Natural Deep Eutectic Solvent.

Due to their outstanding physicochemical properties, the next generation of the graphene family-graphene quantum dots (GQDs)-are at the cutting edge of nanotechnology development. GQDs generally possess many hydrophilic functionalities which allow their dispersibility in water but, on the other hand, could interfere with reactions that are mainly performed in organic solvents, as for cycloaddition reactions. We investigated the 1,3-dipolar cycloaddition (1,3-DCA) reactions of the C-ethoxycarbonyl N-methyl nitrone 1a and the newly synthesized C-diethoxyphosphorylpropilidene N-benzyl nitrone 1b with the surface of GQDs, affording the isoxazolidine cycloadducts isox-GQDs 2a and isox-GQDs 2b. Reactions were performed in mild and eco-friendly conditions, through the use of a natural deep eutectic solvent (NADES), free of chloride or any metal ions in its composition, and formed by the zwitterionic trimethylglycine as the -bond acceptor, and glycolic acid as the hydrogen-bond donor. The results reported in this study have for the first time proved the possibility of performing cycloaddition reactions directly to the p-cloud of the GQDs surface. The use of DES for the cycloaddition reactions on GQDs, other than to improve the solubility of reactants, has been shown to bring additional advantages because of the great affinity of these green solvents with aromatic systems.

Supramolecular Sensing of a Chemical Warfare Agents Simulant by Functionalized Carbon Nanoparticles.

Real-time sensing of chemical warfare agents by optical sensors is today a crucial target to prevent terroristic attacks by chemical weapons. Here the synthesis, characterization and detection properties of a new sensor, based on covalently functionalized carbon nanoparticles, are reported. This nanosensor exploits noncovalent interactions, in particular hydrogen bonds, to detect DMMP, a simulant of nerve agents. The nanostructure of the sensor combined with the supramolecular sensing approach leads to high binding constant affinity, high selectivity and the possibility to reuse the sensor.

Covalently Conjugated Gold-Porphyrin Nanostructures.

Gold nanoparticles show important electronic and optical properties, owing to their size, shape, and electronic structures. Indeed, gold nanoparticles containing no more than 30-40 atoms are only luminescent, while nanometer-sized gold nanoparticles only show surface plasmon resonance. Therefore, it appears that gold nanoparticles can alternatively be luminescent or plasmonic and this represents a severe restriction for their use as optical material. The aim of our study was the fabrication of nanoscale assembly of Au nanoparticles with bi-functional porphyrin molecules that work as bridges between different gold nanoparticles. This functional architecture not only exhibits a strong surface plasmon, due to the Au nanoparticles, but also a strong luminescence signal due to porphyrin molecules, thus, behaving as an artificial organized plasmonic and fluorescent network. Mutual Au nanoparticles-porphyrin interactions tune the Au network size whose dimension can easily be read out, being the position of the surface plasmon resonance strongly indicative of this size. The present system can be used for all the applications requiring plasmonic and luminescent emitters.

Optimization of ZnO Nanorods Growth on Polyetheresulfone Electrospun Mats to Promote Antibacterial Properties.

Zinc oxide (ZnO) nanorods grown by chemical bath deposition (CBD) on the surface of polyetheresulfone (PES) electrospun fibers confer antimicrobial properties to the obtained hybrid inorganic-polymeric PES/ZnO mats. In particular, a decrement of bacteria colony forming units (CFU) is observed for both negative (Escherichia coli) and positive (Staphylococcus aureus and Staphylococcus epidermidis) Grams. Since antimicrobial action is strictly related to the quantity of ZnO present on surface, a CBD process optimization is performed to achieve the best results in terms of coverage uniformity and reproducibility. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) provide morphological and compositional analysis of PES/ZnO mats while thermogravimetric analysis (TGA) is useful to assess the best process conditions to guarantee the higher amount of ZnO with respect to PES scaffold. Biocidal action is associated to Zn2+ ion leaching in solution, easily indicated by UV-Vis measurement of metallation of free porphyrin layers deposited on glass.

High-Mobility Hydrogenated Fluorine-Doped Indium Oxide Film for Passivating Contacts c-Si Solar Cells.

Broadband transparent conductive oxide layers with high electron mobility (µe) are essential to further enhance crystalline silicon (c-Si) solar cell performances. Although metallic cation-doped In2O3 thin films with high µe (>60 cm2 V-1 s-1) have been extensively investigated, the research regarding anion doping is still under development. In particular, fluorine-doped indium oxide (IFO) shows promising optoelectrical properties; however, they have not been tested on c-Si solar cells with passivating contacts. Here, we investigate the properties of hydrogenated IFO (IFO:H) films processed at low substrate temperature and power density by varying the water vapor pressure during deposition. The optimized IFO:H shows a remarkably high µe of 87 cm2 V-1 s-1, a carrier density of 1.2 × 1020 cm-3, and resistivity of 6.2 × 10-4 Ω cm. Then, we analyzed the compositional, structural, and optoelectrical properties of the optimal IFO:H film. The high quality of the layer was confirmed by the low Urbach energy of 197 meV, compared to 444 meV obtained on the reference indium tin oxide. We implemented IFO:H into different front/back-contacted solar cells with passivating contacts processed at high and low temperatures, obtaining a significant short-circuit current gain of 1.53 mA cm-2. The best solar cell shows a conversion efficiency of 21.1%.

Fast and Efficient Sun Light Photocatalytic Activity of Au_ZnO Core-Shell Nanoparticles Prepared by a One-Pot Synthesis.

Gold nanostructures absorb visible light and show localized surface plasmon resonance bands in the visible region. Semiconducting ZnO nanostructures are excellent for ultraviolet detection, thanks to their wide band gap, large free exciton binding energy, and high electron mobility. Therefore, the coupling of gold and ZnO nanostructures represents the best-suited way to boost photodetection. With the above perspective, we report on the high photocatalytic activity of some Au_ZnO core-shell nanoparticles (NPs) recently prepared by a one-pot synthesis in which a [zinc citrate]- complex acted as the ZnO precursor, a reducing agent for Au3+, and a capping anion for the obtained Au NPs. The overall nanostructures proved to be Au(111) NPs surrounded by a thin layer of [zinc citrate]- that evolved to Au_ZnO core-shell nanostructures. Worthy of note, with this photocatalyst, sun light efficiently decomposes a standard methylene blue solution according to ISO 10678:2010. We rationalized photodetection, reaction rate, and quantum efficiency.

Polyethersulfone Mats Functionalized with Porphyrin for Removal of Para-nitroaniline from Aqueous Solution.

The dispersion of para-nitroaniline (p-NA) in water poses a threat to the environment and human health. Therefore, the development of functional adsorbents to remove this harmful compound is crucial to the implementation of wastewater purification strategies, and electrospun mats represent a versatile and cost-effective class of materials that are useful for this application. In the present study, we tested the ability of some polyethersulfone (PES) nanofibers containing adsorbed porphyrin molecules to remove p-NA from water. The functional mats in this study were obtained by two different approaches based on fiber impregnation or doping. In particular, meso-tetraphenyl porphyrin (H2TPP) or zinc(II) meso-tetraphenyl porphyrin (ZnTPP) were immobilized on the surface of PES fiber mats by dip-coating or added to the PES electrospun solution to obtain porphyrin-doped PES mats. The presence of porphyrins on the fiber surfaces was confirmed by UV-Vis spectroscopy, fluorescence measurements, and XPS analysis. p-NA removal from water solutions was spectrophotometrically detected and evaluated.

Supramolecular Detection of a Nerve Agent Simulant by Fluorescent Zn-Salen Oligomer Receptors.

We report on new Zn-Salen oligomer receptors able to recognize a nerve agent simulant, namely dimethyl methylphosphonate (DMMP), by a supramolecular approach. In particular, three Zn-Salen oligomers (Zn-Oligo-A, -B, and -C), differing by the length distribution, were obtained and characterized by NMR, Gel Permeation Chromatography (GPC), UV-Vis, and fluorescence spectroscopy. Furthermore, we investigated their recognition properties towards DMMP by using fluorescence measurements. We found that the recognition ability depends on the length of the oligomeric chain, and the Zn-Oligo-C shows a binding constant value higher than those already reported in literature for the DMMP detection.

Efficacy of gummy lozenges containing Erysimum as ancillary treatment in children with sore throat.

BACKGROUND: Sore throat frequently occurs in children aged between four and fifteen years and is often associated to inflammation of the upper respiratory tract mucosa. A reliable approach to limit the damage caused by inflammation and, therefore, to alleviate associated symptoms might be the protection of the mucosa. Aim of this study was to assess the efficacy and tolerability of a medical device, formulated as a gummy lozenge and containing a combination of natural functional components (Erysimum, aloe vera and Xilogel®) able to exert a barrier effect on the mucosa, as ancillary treatment in children with sore throat. METHODS: This was an observational, prospective, parallel-group, multiple-dose trial of a medical device given in association to standard pharmacological prescribed therapy with an open label comparison vs. standard pharmacological prescribed therapy alone. The outcome measures of the study were assessed at baseline and after three days of treatment. RESULTS: One hundred and twelve school children with sore throat symptoms were recruited for this study and 69 were assigned to the group taking the study product. At the end of the treatment a statistically higher reduction in Sore Throat Pain Intensity Score and Pharyngitis Symptom Score was observed in the group taking the medical device. Moreover, the treatment with the medical device is associated to a statistically significant higher improvement of Child's General Conditions. The pediatrician assessed the efficacy and tolerability of the product under study as good/very good in 91% and 94%, respectively, of treated children. The consumer satisfaction questionnaire revealed that most of the children taking the lozenge rated it very positively in regard to its flavor and easiness of administration. CONCLUSIONS: The medical device used in this study may represent a valid choice as an adjuvant treatment in children with sore throat associated to upper respiratory tract infection.

Supramolecular recognition of a CWA simulant by metal-salen complexes: the first multi-topic approach.

Sensing of chemical warfare agents is today an important target, mainly due to the international scenario. Here a new approach, based on supramolecular multi-topic recognition of dimethyl methylphosphonate, a simulant of chemical warfare agents, is reported. These receptors, based on metal-salen complexes, combine their abilities to establish Lewis acid-base interactions and hydrogen bonds and pave the way for the realization of a new class of supramolecular sensors for the non-covalent recognition of chemical warfare agent simulants.