The effectiveness of a novel binary matrix composed of 1,8-bis(dimethylamino)naphthalene (DMAN;proton sponge) and 9-aminoacridine (9AA) for the direct lipid analysis of whole bacterial cells by matrixassisted laser desorption ionization mass spectrometry (MALDI MS) is demonstrated. Deprotonated ana-lyte signals nearly free of matrix-related ions were observed in negative ion mode. The effect of themost important factors (laser energy, pulse voltage, DMAN/9AA ratio, analyte/matrix ratio) was investi-gated using a Box–Behnken response surface design followed by multi-response optimization in order tosimultaneously maximize signal-to-noise (S/N) ratio and resolution. The chemical surface compositionof single or mixed matrices was explored by X-ray photoelectron spectroscopy (XPS). Moreover, XPSimaging was used to map the spatial distribution of a model phospholipid in single or binary matrices.The DMAN/9AA binary matrix was then successfully applied to the analysis of intact Gram positive(Lactobacillus sanfranciscensis) or Gram negative (Escherichia coli) microorganisms. About fifty majormembrane components (free fatty acids, mono-, di- and tri-glycerides, phospholipids, glycolipids andcardiolipins) were quickly and easily detected over a mass range spanning from ca. 200 to ca. 1600 m/z.Moreover, mass spectra with improved S/N ratio (compared to single matrices), reduced chemical noiseand no formation of matrix-clusters were invariably obtained demonstrating the potential of this binarymatrix to improve sensitivity.

Silicon-Carbon Nanotube radiation detectors need an electrically conductive coating layer to avoid the nanotube detachment from the silicon substrate and uniformly transmit the electric field to the entire nanotube active surface. Coating material must be transparent to the radiation of interest, and must provide the drain voltage necessary to collect charges generated by incident photons. For this purpose various materials have been tested and proposed in photodetector and photoconverter applications. In this article interface properties and electrical contact behavior of Indium Tin Oxide films on Carbon Nanotubes have been analyzed. Ion Beam Sputtering has been used to grow the transparent conductive layer on the nanotubes. The films were deposited at room temperature with Oxygen/Argon mixture into the sputtering beam, at fixed current and for different beam energies. Optical and electrical analyses have been performed on films. Surface chemical analysis and in depth profiling results obtained by X-ray Photoelectron Spectroscopy of the Indium Tin Oxide layer on nanotubes have been used to obtain the interface composition. Results have been applied in photodetectors realization based on multi wall Carbon Nanotubes on silicon.

Increased need for non-destructive investigation methods in archaeology has become a major issue since sampling is in most cases restricted in view of the importance or uniqueness of the objects. For this reason, preliminary investigation using non-destructive techniques was performed on five samples of amber beads obtained from different excavation and archaeological sites. The use of FTIR and micro-Raman analysis revealed the presence of carboxyl, peroxide, hydroxyl, and complex ester functional groups as well as single and double bonds in the structure of the studied resin varieties. Further analysis of the amber samples from both archaeological and geological types by XPS, XRF, and SEM showed the presence of sulfur and a wide range of trace elements on the surface of the analysed samples. Our results proved that the combination of structural-molecular and surface elemental techniques for amber characterisation provides a very useful and simple methodology for the description of geological and archaeological amber samples from different regions of Europe.

Bio-plastics are starting to graduate from the 'emerging technology' stage to market acceptance as everyday materials. In the present study, nanocomposite coatings embedding copper nanoparticles (CuNPs) were developed as new active packaging for fresh dairy products. In order to combine the bioactivity of CuNPs with a biodegradable polymer matrix, copper nanoparticles were satisfactorily incorporated into polylactic acid (PLA). Two different routes were carried out to prepare active films by picosecond-pulsed laser ablation. The nano-materials were characterized by UV-Vis spectroscopy and X-ray Photoelectron spectroscopy. Copper release was also measured through atomic absorption analyses. To assess the antimicrobial effects of nanocomposite systems, both in vitro and in vivo tests were carried out. The active polylactic acid films showed good antibacterial activity. In fiordilatte samples stored at 4 C during 9 days, proliferation of main spoilage microorganisms was delayed with a consequent preservation of sensory attributes. These results represent a step forward in the possible application of copper in the food packaging industry. Industrial relevance Bio-plastics with active properties represent the most emerging technology in food packaging field. Results from the current paper demonstrate that antimicrobial films of PLA embedding copper nanoparticles could be developed and applied to fresh dairy products as fiordilatte. In fact, the in vivo test confirmed the antimicrobial effects on fiordilatte spoilage, without compromising sensory attributes. Results could gain great importance from the industrial dairy sector.

Smart, MEMS-based biosensors are a promising new platform for the delivery of diagnostic services, but inclusion of on-chip CMOS electronics requires the definition a CMOS compatible techniques for the bio-activation of the sensor surface. In this work, a comparison between a sensor functionalization procedure by complete immersion of the sensor chip or by exposure to a single drop of the reagents (the latter approach being more compatible with the presence of on-chip CMOS components) is presented.

A new type of nanomaterial has been developed as antibacterial additive for food packaging applications. This nanocomposite is composed of copper nanoparticles embedded in polylactic acid, combining the antibacterial properties of copper nanoparticles with the biodegradability of the polymer matrix. Metal nanoparticles have been synthesised by means of laser ablation, a rising and easy route to prepare nanostructures without any capping agent in a liquid environment. As prepared, nanoparticle suspensions have been easily mixed to a polymer solution. The resulting hybrid solutions have been deposited by drop casting, thus obtaining self-standing antibacterial packages. All samples have been characterized by UV-Vis spectroscopy, X-ray photoelectron spectroscopy and electro-thermal atomic absorption spectroscopy. Ion release data have been matched with bioactivity tests performed by Japanese Industrial Standard (JIS) method (JIS Z 2801:2000) against Pseudomonas spp., a very common Gram-negative microbial group able to proliferate in processed food.

Gold nanoparticles stabilized on metal oxide supports have found a wide range of applications especially in heterogeneous catalysis and gas sensing. A facile methodology for the in situ electrodecoration of gold nanoparticles on metal oxide supports is presented herein. Metal oxides such as indium oxide (In2O3) and zirconia (ZrO2) nanoparticles are first prepared via the sol-gel route. Subsequently, gold nanoparticles are electrodeposited in situ on the surface of these metal oxides using a modified sacrificial Au-anode electrolysis procedure. Both pristine as well as electrodecorated metal oxides are characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning and transmission electron microscopies (SEM, TEM). SEM images of electrodecorated metal oxides reveal successful deposition of gold nanoparticles on metal oxide supports. XPS shows that nano-sized gold is significantly available on the materials' surface and it is in the elemental oxidation state. Moreover, it is found that the electrodecoration of gold nanoparticles on metal oxide surfaces proceeds as a function of the concentration of hydroxyl groups on the surface of metal oxide supports.

Among the metal oxide semiconductors, ZnO has been widely investigated as a channel in thin film transistors (TFTs) due to its excellent electrical properties, optical transparency and simple fabrication via solution processed techniques. Herein, we are reporting a solution processable ZnO based thin-film transistor, gated through a liquid electrolyte having an ionic strength comparable to that of a physiological fluid. The surface morphology and chemical composition of the ZnO films upon exposure to water and phosphate buffer solution (PBS), are discussed in terms of operation stability and electrical performance of the ZnO TFT devices. Improved device characteristics upon exposure to PBS are associated with the enhancement of the oxygen vacancies in ZnO lattice, possibly due to Na+ doping. Moreover, dissolution kinetics of ZnO thin film in liquid electrolyte opens to possible applicability of these devices as active element in “transient” implantable systems.

In this study, a preventive method for fighting bio-deterioration of stone substrates is proposed. This is based on the use of bioactive zinc oxide nanoparticles (ZnO-NPs), which are able to exert a marked biological activity over a long period of time due to their peculiar structure. ZnO-NPs are synthesised by a simple and reproducible electrochemical procedure. The nanomaterials are embedded in consolidant/ water-repellent matrices to obtain nanostructured coatings. Commonly used products based on tetraethoxysilane and/or polysiloxanes were tested. The resulting nanomaterials were fully characterised by X-ray photoelectron spectroscopy (XPS) to investigate the amount and composition of the NPs and the behaviour of the nanocomposites. Inductively coupled plasma mass spectrometry (ICP-MS) was used for the study of the release of metal from the composites when put in contact with artificial rainwater. The nanocomposites were applied to specimens composed of three different types of stone and chromatic changes upon curing were measured by spectrophotocolorimetry. Finally, morphological characterization by scanning electron microscopy (SEM) was performed. The bioactivity of ZnO-NPs nanocomposites was also assessed in preliminary tests against Aspergillus niger fungus

Synthesis and fabrication and assembly of functional particles and capsules Material Research Society, San Francisco (USA), April 2012

A group of enamelled and gilded glass objects, coming from Melfi Castle (PZ - Italy) from an area dated to the period between the end of the 12th and the last quarter of the 13th century, offered the opportunity to closely investigate this technology with the aim of understanding the raw materials and the procedures employed to realize the objects and their precious decorations. Optical microscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, Raman spectroscopy, laser ablation-inductively coupled plasma-mass spectrometry and X-Ray photoelectron spectroscopy were used to observe and analyze the glass, the enamels, the gildings and their mutual relations. The bulk of the objects resulted a soda-lime glass, while the enamels are lead-based 'soft' enamels or soda-lime glass; the palette of pigments employed to obtain their colours included iron III oxide and minium for red, lazurite and/or cobalt for blue, lead-tin-antimony pyrochlore solid solution oxide (yellow) plus cobalt for green, manganese oxides for black and calcium phosphate for white. Results obtained for gilding, in particular stratigraphy and morphology, suggest the use of the so called 'liquid gold'.

Gold (Au) nanoparticles stabilized on metal oxide supports offer superior catalytic activity and recyclability in organic catalysis. We report for the first time synthesis of indium oxide stabilized gold (Au@In2O 3) nanocatalysts using an electrochemical procedure and their application in homocoupling of arylboronic acids. In2O3 nanoparticles prepared via sol-gel process are subjected to sacrificial anode electrolysis (SAE) under inert condition for electrodeposition of nano Au on In2O3. Thus Au@In2O3 nanoparticles obtained are thermally annealed at high temperature to partially oxidize Au and to remove any surfactants. XPS results show the existence of both elemental (nano Au0) and cationic (Au3+) species in Au@In 2O3 nanocatalysts, while SEM images confirm the presence of nanoscale Au (<10 nm) particles on In2O3 surface. Au@In2O3 nanocatalysts are tested for arylboronic acids homocoupling under different conditions and it is found that they are highly active in organic medium with K2CO3 base and demonstrate excellent conversion (>97%) and selectivity (>98%). The catalyst recyclability and performance towards differently substituted arylboronic acids is also studied and a plausible mechanism of action is proposed.

The present work is aimed at developing gold nanostructures functionalized with antenna systems to exploit the synergistic nanostructure/antenna desorption-ionization efficiency. A potential Matrix- Assisted Laser Desorption Ionisation (MALDI) organic matrix has been modified introducing specific functional groups or molecular linker and used as a capping agent for gold nanostructures. In particular, conjugated naphthyl-thio-derivative, i.e. 4-mercaptonaphthalene-1,8-dicarboxylic acid, was synthesized and characterized by means of nuclear magnetic resonance, UVevisible and X-ray photoelectron spectroscopies. Afterwards, the thio-derivative was used as covalent surface modifier for flat gold surfaces and nanostructured gold films. These surfaces were thoroughly characterized by means of parallel angle-resolved X-ray photoelectron spectroscopy to obtain quantitative information about elemental composition, chemical speciation, and in-depth distribution of the target chemical functional groups. Finally the compound was preliminarily tested as a non-conventional matrix in Laser Desorption Ionisation Mass Spectrometry (LDI-MS) analysis of low molecular weight biomolecules in order to assess its capability of acting as the antenna system and proton donor after covalent bonding to gold nanomaterials.

Automobile exhaust gas emissions are causing serious damage to urban air quality in and around major cities of the world, which demands continuous monitoring of exhaust emissions. The chief components of automobile exhaust include carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons. Indium zirconate (InZrOx) and gold/indium zirconate (Au/InZrOx) composite nanopowders are believed to be interesting materials to detect these substances. To this end, characterization and gas sensing properties of InZrOx and Au/InZrOx composite nanopowders are discussed. InZrOx nanoparticles with In/Zr atomic ratio of 1.00 (±0.05) are synthesized via pH-controlled co-precipitation of In and Zr salts in aqueous ammonia. Gold (Au) nanoparticles are subsequently deposited on InZrOx using an in situ sacrificial Au electrolysis procedure. The products are characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The gas sensing performance of Au/InZrOx composite nanopowder is studied by depositing a thick powder film on interdigitated electrode structures patterned on SiC substrate to facilitate high temperature operation. The resistivity of the Au/InZrOx layer is the sensor signal, and the sensors could be operated at 500–600 °C, which is a suitable temperature range for engine exhaust measurements. The control sensing measurements reveal that Au/InZrOx composite nanopowder exhibits higher response towards 2–20 % O2 gas as compared to pristine InZrOx nanoparticles. Further studies show that when applied to exhaust gases such as CO and nitric oxide (NO), the response of Au/InZrOx sensors is significantly higher towards NO in this temperature range. Thus, sensor performance characteristics of Au/InZrOx composite nanopowder are promising in terms of their applications in automobile exhaust emission control.

In the present study, gold/surfactant core/shell colloidal nanoparticles with a controlled morphology and chemical composition have been obtained via the so-called sacrificial anode technique, carried out in galvanostatic mode. As synthesized Au-NPs had an average core diameter comprised between 4 and 8 nm, as a function of the electrochemical process experimental conditions. The UV–Vis characterization of gold nanocolloids showed clear spectroscopic size effects, affecting both the position and width of the nanoparticle surface plasmon resonance peak. The nanomaterial surface spectroscopic characterization showed the presence of two chemical states, namely nanostructured Au(0) (its abundance being higher than 90%) and Au(I). Au-NPs were then deposited on the top of a capacitive field effect sensor and subjected to a mild thermal annealing aiming at removing the excess of stabilizing surfactant molecules. Au-NP sensors were tested towards some gases found in automotive gas exhausts. The sensing device showed the largest response towards NOx, and much smaller – if any – responses towards interferent species such as NH3, H2, CO, and hydrocarbons.

Graphene/ionic liquids nanocomposite gels were synthesized by an electrochemical etching approach and fully characterized under a morphological and structural point of view. For this purpose, several analytical techniques were applied, as HR-TEM/EDX (High Resolution-Transmission Electron Microscopy/Energy Dispersive X-Ray Analysis); FE-SEM/EDX (Field Emission-Scanning Electron Microscopy/Energy Dispersive X-Ray Analysis); XPS (X-Ray Photoelectron Spectroscopy); FT-IR (Fourier Transform-Infrared Spectroscopy) and electrochemical techniques. After the characterization study, nanocomposite-gel paste electrodes were assembled, exhibiting a selective and specific detection toward the caffeic acid oxidation. Better performances in terms of linear range of concentration (from 0.025 to 2.00 M), reproducibility (intra-; 1.40% and inter-electrode reproducibility-3.20%), sensitivity (3389/μA mM-1 cm-2), fast response time (2 s) and detection limit (0.005 mM) were obtained, in comparison with other chemically modified electrodes, described in literature for the caffeic acid detection. This nanocoposite-gel could represent a new prototype of miniaturized nanostructured sensors useful for the "in situ" quantification of an important molecule, having pharmacological properties, anti-inflammatory, antibacterial, antiviral, immunomodulatory and antioxidant effects.

Oxidized Single-Wall Carbon Nanohorns (o-SWCNHs) were used, for the first time, to assemble chemically modified Screen Printed Electrodes (SPEs) selective towards the electrochemical detection of Epinephrine (Ep), in the presence of Serotonine-5-HT (S-5HT), Dopamine (DA), Nor-Epineprhine (Nor- Ep), Ascorbic Acid (AA), Acetaminophen (Ac) and Uric Acid (UA). The Ep neurotransmitter was detected by using Differential Pulse Voltammetry (DPV), in a wide linear range of concentration (2–2500 μM) with high sensitivity (55.77 A M1 cm2), very good reproducibility (RSD% ranging from 2 to 10 for different SPEs), short response time for each measurement (only 2 s) and low detection of limit (LOD¼0.1 μM). o-SWCNHs resulted in higher analytical performances when compared with other nanomaterials used in literature for electrochemical sensors assembly.

Clay minerals have revealed highly potential in soil remediation due to their low cost, availability, and low toxicity. Mechanochemical processes allow to activate chemical reactions by inducing different kinds of mechanical stress and without any other energy supply. This study investigated the effect of dry milling on the ability of dioctahedral and trioctahedral smectites to immobilize heavy metals cations. To this purpose a dioctahedral smectite “bentolite L” and a trioctahedral one “laponite RD” were ground with different amount of copper(II) chloride in dry conditions into a zirconia planetary ball mill (mechanochemical treatment). Increasing milling time and Cu/clay minerals mass ratio were selected for experimental tests. From the ground mixtures two different kinds of samples were extracted using the following procedures: 1) with deionised water; 2) with 1 M MgCl2 solution. Copper immobilization degree was evaluated by ICP/OES analysis of exstracts as difference between the amount of Cu(II) spiked in the mixture and the amount of Cu(II) ions present in the extracted fraction. The analyses showed an increased Cu retention as time increases for both bentolite L and laponite RD. Mechanochemical treatments, depending on time and different mass ratio, induced the increase of retention efficiency. The solid phases were also characterized by means of solid-state NMR and spectroscopic techniques such as FTIR and XPS, to investigate the mechanisms of the “mechanochemical retention” of copper by both the clay minerals

Research on the nanomaterials containing one or more transition metals is growing tremendously, thanks to the large number of preparation processes available and to the novel applications that can be envisaged in several fields. This review presents an overview of the selected studies in the field of antimicrobial textiles, employing bioactive nanophases of elements/compounds such as silver, copper, or zinc oxide. In addition, the history of use of these antimicrobials and their mechanism of action are shortly reported. Finally, a short description is provided of the deposition/preparation methods, which are being used in the authors ’ labs for the development of the textiles modified by the novel nanoantimicrobials

The aim of the present work was to compare the mucoadhesive and efflux pump P-glycoprotein (P-gp) interacting properties of chitosan (CS)- and glycolchitosan (GCS)-based thiomers and corresponding unmodified parent polymers. For this purpose, the glycol chitosan-N-acetyl-cysteine (GCS-NAC) and glycol chitosan-glutathione (GCS-GSH) thiomers were prepared under simple and mild conditions. Their mucoadhesive characteristics were studied by turbidimetric and zeta potential measurements. The P-gp interacting properties were evaluated measuring the effects of thiolated- and unmodified-polymers on the bidirectional transport (BA/AB) of rhodamine-123 across Caco-2 cells as well as in the calcein-AM and ATPase activity assays. Although all the thiomers and unmodified polymers showed optimal-excellent mucoadhesive properties, the best mucoadhesive performances have been obtained by CS and CS-based thiomers. Moreover, it was found that the pretreatment of Caco-2 cell monolayer with GCS-NAC or GCS restores Rho-123 cell entrance by inhibiting P-gp activity. Hence, GCS-NAC and GCS may constitute new biomaterials useful for improving the bioavailability of P-gp substrates.

Gilded and enamelled glasses of Islamic style, coming from a 13th century landfill in Melfi castle, a Swabian emperor Frederick II fortress, were subjected to a multi-techniques approach in order to explore the complex and very fascinating ancient production technology of gilding and enamelling on glass. Non-destructive μ-Raman spectroscopy was employed on the most important and well-preserved objects, optical (OM) and electron (SEM) microscopies were used to investigate the sections stratigraphy of tiny fragments sampled from the borders of the already damaged objects. In order to provide the chemical analyses of the bodies and the enamels, energy dispersive X-rays spectroscopy (EDS) and X-rays photoelectron spectroscopy (XPS) were also employed. The body of the objects proved to be made of silica-soda-lime glass, while the enamels of lead-rich glass (“soft enamels”) and coloured by lapis lazuli and cobalt for blue, hematite and minium for red, lead-tin yellow for green and calcium phosphate for white. The gilding was found to be applied on a red enamel basis. The presence of carbon inside the gildings and the detection of two different gold signals by XPS suggested the hypothesis of the use of the so-called “liquid gold”. This study gave thus an important contribution to the understanding of the production of this class of rare and precious objects, also confirming that the materials and technological procedures are consistent with the Islamic tradition, probably due to the presence of Islamic artisans at the court of Frederick II.

In the present contribution Angle Resolved X-ray Photoelectron Spectroscopy (AR-XPS) was proposed as useful tool to address the challenge of probing the near-surface region of bio-active sensors surface. A model bio-functionalized surface was characterized by Parallel AR-XPS and commercially available Thermo Avantage-ARProcess software was used to generate non-destructive concentration depth profiles of protein functionalized silicon oxide substrates. At each step of the functionalization procedure, the surface composition, the overlayer thickness, the in-depth organization and the in-plane homogeneity were evaluated. The critical discussion of the generated profiles highlighted the relevance of the information provided by PAR-XPS technique.

Label-free biosensors are of considerable interest for various clinical and biological applications. In these systems, achieving an optimized receptor immobilization strategy critically influence the sensing performance in terms of specificity, sensitivity, response kinetics and detection limits. However, monitoring the receptor spatial organization and the interfaces composition on a nanometer or sub-nanometer scale is a very hard challenge. In the present contribution Parallel Angle Resolved X-ray Photoelectron Spectroscopy (PAR-XPS) was proposed as useful tool to address the challenge of probing the near-surface region of bio-active sensors surface (1). A model receptor was chosen and a well-established functionalization procedure (2) was systematically characterized by PAR-XPS. Commercially available Thermo Avantage-ARProcess software was used to generate non-destructive concentration depth profiles of protein functionalized silicon oxide substrates. At each step of the functionalization procedure, the surface composition, the over layer thickness, the in-depth organization and the in-plane homogeneity were evaluated. Compared to multi-techniques characterization approaches previously proposed in the literature, the present analytical approach boasted the peculiar advantage of providing, simultaneously, morphological and compositional information from the same data set. The critical discussion of the generated profiles highlighted the relevance of the information provided by PAR-XPS technique.

A plasma enhanced chemical vapor deposition process was proposed to functionalize the P3HT organic semiconductor surface of electrolyte gated organic field effect transistors with hydrophilic coatings bearing –COOH groups. Results demonstrate that the developed plasma process allows to functionalize the P3HT surfaces with carboxyl groups with negligible adverse effect on the bulk properties of P3HT as well as on EGOFET performances.

In this paper a study of Multi Wall Carbon Nanotube films deposited at low temperature by means of a spray technique on different substrates is presented. Nanodispersion of nanotube powder in a non-polar 1,2-dichloroethane solvent was used as starting solution. Electron Microscopy in Scanning and Transmission modes were used in order to verify the morphological properties of the deposited films. Visible light detectors were prepared spraying Multi Wall Carbon Nanotubes on silicon substrates with different layouts. In some detectors the nanotubes were covered by an Indium Tin Oxide (ITO) layer. Electrical measurements, both in dark and under light irradiation, were performed and Current-Voltage characteristics are reported. The Indium Tin Oxide coating effect on the photoconductivity yield is presented and discussed along with device ageing test, resulting in a very good photoconduction and stability over four months.

Single-Wall Carbon Nanohorns (SWNHs) were discovered by Iijima (1) and represent a new carbon material having a horn-shaped sheath of single-wall graphitic sheets. They associate each other to form a ‘Dahlia- flower’-like aggregate. In this study, SWNHs were characterized by using HR-TEM (High-Resolution Transmission Electron Microscopy), FE-SEM/EDX (Field Emission-Scanning Electron Microscopy), Raman spectroscopy, FT-IR (Fourier Transform-Infrared) spectroscopy, XPS (X-ray Photoelectron Spectroscopy), XRD (X-ray Diffraction) and TG/DTA (Differential Thermogravimetric analysis). Then, a stable and homogeneous SWNHs colloid phase, realized in ethanolic medium, was subsequently used to chemically modify SPEs surfaces (2). The modified electrochemical devices were applied for the detection of H2O2, β-NADH, several neurotransmitters, ascorbic, uric and caffeic acids, guanine and tyrosine, very important targets for interesting bio-medical applications (3).

The on–board quantification of exhaust emission from the internal combustion engines is of global concern in order to monitor and control release of toxic gaseous pollutants such as the oxides of nitrogen (NOx). This scenario calls for highly performing, cost–effective and long lasting gas sensors. In this regard, semiconducting metal oxides present the foremost choice of active materials for real–time detection of exhaust gases due to their low cost, good electrical properties, high sensitivity and stability at temperatures as high as >500°C [1]. In this work, we report on the synthesis, analytical characterization, and surface modification of metal oxide nanoparticles (ZnO–, ZrOx, InOx- NPs) for their potential application as semiconductor gas sensors. ZnO is a promising material and one of the earliest oxides studied for gas adsorption [2]. However, owing to its high working temperature and limited selectivity, ZnO did not achieve commercial success. ZrOx and InOx nanomaterials are well known active components of NOx sensors, which have shown some performance limitations –either in selectivity or in response intensity and kinetics-. To overcome these limitations, in recent years semiconductor metal oxides (MO) are being frequently modified by selected inclusions of transition metal nanoparticles, bringing their own surface reactivity characteristics to the hybrid catalyst-MO system [3]. In the present study, MO–NPs are prepared via simple and economical sol–gel methods. The surface of MO–NPs is subsequently modified by electro–chemical decoration of nanoscale gold (nano–Au), performed under surfactant stabilization conditions. Since Au nanoparticles exhibit pronounced selectivity toward NOx gases [4], the nano–Au/MO–NPs hybrids are believed to enhance the sensing properties of MO–NPs such as the selectivity and long–term stability of the nanomaterial. Both the pristine MO–NPs and the composite nano–Au/MO–NPs are calcined at temperatures >500°C to induce stability at the usual operating temperature of gas-sensing experiments and the effect of calcination on nanostructure and morphology is systematically studied. The as–prepared and the calcined nanomaterials are characterized by transmission electron microscopy, scanning electron microscopy, X–ray photoelectron spectroscopy, and X–ray diffraction techniques. The results demonstrate that these nanomaterials are highly stable and even ultrafine gold nanophases retain their morphology and surface chemical speciation upon annealing. The experimental evidences support further application of these composite nano–Au/MO–NPs as active elements in semiconductor NOx gas sensors.

The presence of heavy metals in the environment is a potential risk for the ecosystem due to their toxicity to plant, animals and human life. Lots of technologies and treatments have been developed to remove them from aqueous solutions, employing natural or synthetic sorbents. Among them, clay minerals have revealed interesting properties in soil remediation due to their natural occurrence, low toxicity, and low cost. Moreover, mechanochemical processes allow to activate chemical reactions by inducing different kinds of mechanical stress and without any other energy supply. In this study the effect of mechanochemical treatments on the ability of dioctahedral and trioctahedral smectites to “entrap” heavy metals is investigated. To this purpose a dioctahedral smectite “bentolite L” and a trioctahedral one “laponite RD” were ground with different distinct amounts of copper and cadmium chloride in dry conditions by means of zirconia planetary ball mill. Experimental tests were performed modifying the milling time and metal/clay minerals mass ratio, whereas grinding energy and ball to powder ratio were kept constant. The efficiency of the mechanochemical process to promote the interaction between smectites and heavy metals was evaluated by means of different analytical techniques: the immobilization degree was evaluated by ICP/OES analyses and expressed by the leachable fraction of metal ions. While the investigation on the main adsorption sites of the heavy metals on the ground surfaces was tested by means of solid-state measurements through the combined use of X-ray Fluorescence Spectroscopy, Fourier Transform Infrared Spectroscopy, X-ray Diffraction, Nuclear Magnetic Resonance and X-ray Photoelectron Spectroscopy.

This work highlights the importance of the hydrophilicity of a catalyst’s active sites on an oxygen reduction reaction (ORR) through an electrochemical and physico-chemical study on catalysts based on nitrogen-modified carbon doped with different metals (Fe, Cu, and a mixture of them). BET, X-ray Powder Diffraction (XRPD), micro-Raman, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Scanning Transmission Electron Microscopy (STEM), and hydrophilicity measurements were performed. All synthesized catalysts are characterized not only by a porous structure, with the porosity distribution centered in the mesoporosity range, but also by the presence of carbon nanostructures. In iron-doped materials, these nanostructures are bamboo-like structures typical of nitrogen carbon nanotubes, which are better organized, in a larger amount, and longer than those in the copper-doped material. Electrochemical ORR results highlight that the presence of iron and nitrogen carbon nanotubes is beneficial to the electroactivity of these materials, but also that the hydrophilicity of the active site is an important parameter affecting electrocatalytic properties. The most active material contains a mixture of Fe and Cu.

The control of pollutants emission from internal combustion engines is a worldwide issue, in the automotive field. The roadmap for the reduction of vehicle emission limits is driving the academic and industrial interest towards the development of innovative systems integrating novel detection elements and fast feedback circuits and actuators. Based on a tighter control over emissions, and starting from 2014, Euro 6 standards are expected to improve the environmental compatibility of a new generation of vehicles in Europe. This scenario calls for a significant improvement of the sensors technologies for the detection of the main pollutants related to the automotive field, including nitrogen oxides (NOx). In this work, we report on the synthesis and analytical characterization of hybrid nanocomposites containing gold nanoparticles (Au-NPs) and metal oxide nanostructures (MO-NPs, such as zirconium oxide, indium oxide, oxide mixtures, etc.). These species are promising for real-time detection of low levels of NOx species, owing to their low cost, high sensitivity and availability under a variety of stoichiometric and mixing ratios, showing different gas sensing characteristics [1- 2]. Different MO-NPs and mixed MO-NP systems were prepared using a simple but efficient sol-gel method. Subsequently, the nano-oxides were electrodecorated by Au-NPs. Since Au nanophases exhibit pronounced selectivity toward NOx gases [3], the resulting hybrid nanocomposites are expected to improve the nanomaterial sensing performance. All the nanomaterials were characterized using FTIR, XPS, XRD, TEM, and SEM techniques. Experimental evidences support further application of these NPs as active elements in novel NOx sensors.

Biological agents play an important role in the deterioration of cultural heritage causing aesthetic, biogeophysical and biogeochemical damages. Conservation is based on the use of preventive and remedial methods. The former aims at inhibiting biological attack, and the latter aims at eradicating the biological agents responsible for biodeterioration. Here, we propose the preparation and the analytical characterisation of copper-based nanocoating, capable of acting both as a remedy and to prevent microbial proliferation. Core–shell CuNPs are mixed with a siliconbased product, commonly used as a water-repellent/consolidant, to obtain a combined bioactive system to be applied on stone substrates. The resulting coatings exert a marked biological activity over a long period of time due to the continuous and controlled release of copper ions acting as biocides. To the best of our knowledge, this is the first time that a multifunctional material is proposed, combining the antimicrobial properties of nanostructured coatings with those of the formulations applied to the restoration of stone artworks. A complete characterisation based on a multitechnique analytical approach is presented.

In this study, two different strategies for the synthesis of graphene are reported. In the first case, Oxidized Graphene Nanoribbons (GO) are obtained by the oxidative unzipping of Single-Wall Carbon Nanotubes (SWCNTs), as described in our previous work (1). Then, GO was dispersed in several different ILs and the resulting nano-dispersion were fully characterized, under a morphological and structural point of view (2). In particular, several studies performed by HR-TEM (High Resolution- Transmission Electron Microscopy), FT-IR (Fourier Transform-Infrared spectroscopy) and XPS (X-ray Photoelectron Spectroscopy), demonstrated that ILs were physically adsorbed on the GO surfaces, their edges and walls. The second approach concerns the electrochemical synthesis of graphene gels, covalently functionalized with ILs (3), by the etching of a graphite anode. Also in this case, HR-TEM, FT-IR and XPS analyses revealed interesting information on the interaction between ILs and GO. In particular, nitrogen XP spectra of functionalized GO presented a component ascribable to the coordination of N with electron-rich functionalities. This experimental evidence was observed in all the materials investigated, no matter the IL.

The aim of this study was to evaluate the performance of chitosan (CS) and glycol chitosan (GCS) nanoparticles containing the surfactant Lipoid S100 for the systemic delivery of low molecular weight heparin (LMWH) upon pulmonary administration. These nanoparticles were prepared in acidic and neutral conditions using the ionotropic gelation technique. The size and zeta potential of the NPs were affected by the pH and also the type of polysaccharide (CS or GCS). The size (between 156 and 385 nm) was smaller and the zeta potential (from +11 mV to +30 mV) higher for CS nanoparticles prepared in acidic conditions. The encapsulation efficiency of LMWH varied between 100% and 43% for the nanoparticles obtained in acidic and neutral conditions, respectively. X-ray photoelectron spectroscopy studies indicated that the surfactant Lipoid S100 was localized on the nanoparticle's surface irrespective of the formulation conditions. In vivo studies showed that systems prepared in acidic conditions did not increase coagulation times when administered to mice by the pulmonary route. In contrast, Lipoid S100-LMWH GCS NPs prepared in neutral conditions showed a pharmacological efficacy. Overall, these results illustrate some promising features of CS-based nanocarriers for pulmonary delivery of LMWH.

Metal nanomaterials have emerging role in surface-assisted laser desorption ionisation–mass spectrometry (SALDI-MS) providing a useful tool to overcome some limitations intrinsically related to the use of conventional organic matrices in matrix-assisted LDI-MS. In this contribution, the possibility to use a stainless steel-supported gold nanoparticle (AuNP) film as a versatile platform for SALDI-MS was assessed. Sacrificial anode electrosynthetic route was chosen in order to obtain morphologically controlled core–shell AuNPs; the colloidal AuNPs were, thereafter, drop cast onto a stainless steel sample plate and the resulting AuNP film was thermally annealed in order to improve its effectiveness as LDI-MS promoter. Spectroscopic characterization of the nanostructured film by X-ray photoelectron spectroscopy was crucial for understanding how annealing induced changes in the surface chemistry and influenced the performance of AuNPs as desorption/ionisation promoter. In particular, it was demonstrated that the post-deposition treatments were essential to enhance the AuNP core/analyte interaction, thus resulting in SALDI-MS spectra of significantly improved quality. The AuNP films were applied to the detection of three different classes of low molecular weight (LMW) analytes, i.e. amino acids, peptides and LMW polymers, in order to demonstrate the versatility of this nanostructured material.

A simple and time-saving wet method to endow the surface of organic semiconductor films with carboxyl functional groups is presented. A thin layer of poly(acrylic acid) (pAA) is spin-coated directly on the electronic channel of an electrolyte-gated organic FET (EGOFET) device and cross-linked by UV exposure without the need for any photo-initiator. The carboxyl functionalities are used to anchor phospholipid bilayers through the reaction with the amino-groups of phosphatidyl-ethanolamine (PE). By loading the membranes with phospholipids carrying specific functionalities, such a platform can be easily implemented with recognition elements. Here the case of biotinylated phospholipids that allow selective streptavidin electronic detection is described. The surface morphology and chemical composition are monitored using SEM and XPS, respectively, during the whole process of bio-functionalization. The electronic and sensing performance level of the EGOFET biosensing platform is also evaluated. Selective analyte (streptavidin) detection in the low pM range is achieved, this being orders of magnitude lower than the performance level obtained by the well assessed surface plasmon resonance assay reaching the nM level, at most.

Chitosan- and glycol-chitosan thiol conjugates have been developed, in order to realize nanocarriers which can be useful in the transmucosal drug delivery. The aim of the study is to compare the mucoadhesive properties of the two classes of conjugates. Indeed, the presence of thiol groups on the polymer surface is expected both to increase the interaction with the mucin and to promote the absorption of the delivered drugs. Glutathione and N-acetylcysteine have been chosen to synthesize new thiol-derivatives of glycol chitosan to be compared to the analogous chitosan derivatives (1) in terms of mucoadhesion properties. All the conjugates have been formulated as promising nanoparticles (NPs) for drug delivery. In the present contribution, x-ray photoelectron spectroscopy has been performed to analyze the surface chemical composition of both the synthesized polymers and the resulting NPs. The preliminary investigations showed the presence of sulphur on the NPs outer shell thus encouraging the eventual surface mucoadhesive properties of the nanocarriers. Further work is in progress to localize the in-depth distribution (2), once the nanocarriers have been loaded with a model drug.