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Low-energy electrons (Auger electrons) can be produced via the interaction of photons with gold atoms in gold nanorods (AuNRs). These electrons are similar to those emitted during the decay of technetium-99m (99mTc), a radioactive nuclide widely used for diagnostics in nuclear medicine. Auger and internal conversion (IC) electron emitters appropriately targeted to the DNA of tumors cells may, therefore, represent a new radiotherapeutic approach. 99mTc radiopharmaceuticals, which are used for diagnosis, could indeed be used in theragnostic fields when loaded on AuNRs and delivered to a tumor site. This work aims to provide a proof of concept (i) to evaluate AuNRs as carriers of 99mTc-based radiopharmaceuticals, and (ii) to evaluate the efficacy of Auger electrons emitted by photon-irradiated AuNRs in inducing radio-induced damage in T98G cells, thus mimicking the effect of Auger electrons emitted during the decay of 99mTc used in clinical settings. Data are presented on AuNRs’ chemical characterization (with an aspect ratio of 3.2 and Surface Plasmon Resonance bands at 520 and 680 nm) and the loading of pharmaceuticals (after 99mTc decay) on their surface. Spectroscopic characterizations, such as UV-Vis and synchrotron radiation-induced X-ray photoelectron (SR-XPS) spectroscopies, were performed to investigate the drug–AuNR interaction. Finally, preliminary radiobiological data on cell killing with AuNRs are presented.

The recognized antibacterial properties of silver nanoparticles (AgNPs) characterize them as attractive nanomaterials for developing new bioactive materials less prone to the development of antibiotic resistance. In this work, we developed new composites based on self-assembling Fmoc-Phe3 peptide hydrogels impregnated with in situ prepared AgNPs. Different methodologies, from traditional to innovative and eco-sustainable, were compared. The obtained composites were characterized from a hydrodynamic, structural, and morphological point of view, using different techniques such as DLS, SEM, and rheological measurements to evaluate how the choice of the reducing agent determines the characteristics of AgNPs and how their presence within the hydrogel affects their structure and properties. Moreover, the antibacterial properties of these composites were tested against S. aureus, a major human pathogen responsible for a wide range of clinical infections. Results demonstrated that the hydrogel composites containing AgNPs (hgel@AgNPs) could represent promising biomaterials for treating S. aureus-related infections.

Phase-transition materials provide exciting opportunities for controlling optical properties of photonic devices dynamically. Here, we systematically investigate the infrared emission from a thin film of vanadium dioxide (VO2). We experimentally demonstrate that such thin films are promising candidates to tune and control the thermal radiation of an underlying hot body with different emissivity features. In particular, we studied two different heat sources with completely different emissivity features, i.e. a black body-like and a mirror-like heated body. The infrared emission characteristics were investigated in the 3.5–5.1 μm spectral range using the infrared thermography technique which included heating the sample, and then cooling back. Experimental results were theoretically analyzed by modelling the VO2 film as a metamaterial for a temperature range close to its critical temperature. Our systematic study reveals that VO2 thin films with just one layer 80 nm thick has the potential to develop completely different dynamic tuning of infrared radiation, enabling both black-body emission suppression and as well as mirror emissivity boosting, in the same single layer device. Understanding the dynamics and effects of thermal tuning on infrared emission will benefit wide range of infrared technologies including thermal emitters, sensors, active IR filters and detectors.

The possibility to use β− decaying isotopes for radioguided surgery (RGS) has been recently proposed, and first promising tests on ex-vivo samples of Meningioma and intestinal Neuroendocrine Tumor (NET) have been published. This paper reports a study of the uptake of 68Ga-DOTATOC in pancreatic NETs (pNETs) in order to assess the feasibility of a new RGS approach using 90Y-DOTATOC. Tumor and healthy pancreas uptakes were estimated from 68Ga-DOTATOC PET/CT scans of 30 patients with pNETs. From the obtained SUVs (Standardised Uptake Value) and TNRs (Tumor Non tumor Ratio), an analysis algorithm relying on a Monte Carlo simulation of the detector has been applied to evaluate the performances of the proposed technique. Almost all considered patients resulted to be compatible with the application of β−-RGS assuming to administer 1.5 MBq/kg of activity of 90Y-DOTATOC 24 h before surgery, and a sampling time of few seconds. In just 2 cases the technique would have required a mildly increased amount of activity or of sampling time. Despite a high physiological uptake of 68Ga-DOTATOC in the healthy pancreas, the proposed RGS technique promises to be effective. This approach allows RGS to find application also in pancreatic diseases, where traditional techniques are not viable.

This paper presents the synthesis of silver nanoparticles (AgNPs) functionalized with fluorescent molecules, in particular with xanthene-based dyes, i.e., fluorescein isothiocyanate (FITC, λmax = 485 nm) and rhodamine B isothiocyanate (RITC, λmax = 555 nm). An in-depth characterization of the particle–dye systems, i.e., AgNPs–RITC and AgNPs–FITC, is presented to evaluate their chemical structure and optical properties due to the interaction between their plasmonic and absorption properties. UV–Vis spectroscopy and the dynamic light scattering (DLS) measurements confirmed the nanosize of the AgNPs–RITC and AgNPs–FITC. Synchrotron radiation X-ray photoelectron spectroscopy (SR-XPS) was used to study the chemical surface functionalization by structural characterization, confirming/examining the isothiocyanate–metal interaction. For AgNPs–RITC, in which the plasmonic and fluorescence peak are not superimposed, the transient dynamics of the dye fluorescence were also studied. Transient absorption measurements showed that by exciting the AgNPs–RITC sample at a wavelength corresponding to the AgNP plasmon resonance, it was possible to preferentially excite the RITC dye molecules attached to the surface of the NPs with respect to the free dye molecules in the solution. These results demonstrate how, by combining plasmonics and fluorescence, these AgNPs can be used as promising systems in biosensing and imaging applications.

Starting from the 2000s, the use of magnetic nanoparticles (MNPs) has begun to find a place in the studies of analyte extraction. Within this framework, the synergic collaboration in analytical chemistry and material sciences has developed several methods for the efficient and rapid extraction of analytes, especially in complex matrices. The main application of MNPs in the extraction step is in the environmental field for example in river water, lake water or industrial discharge samples. Other applications have been found in food and biological analysis, such as for urine or blood samples. In this chapter the use of metal nanoparticles for analyte extraction, and the areas of application, i.e., food, environment, and health, are explored. Moreover, the limits of these new methodologies, the new opportunities that are offered and the challenges of these techniques are highlighted.

Nanomaterials such as gold nanoparticles employed as solid-state sensors have attracted attention in recent years due to their ability to detect poisonous elements in the indoor/outdoor environment. Herein, chemoresistive sensors based on gold nanoparticles (AuNPs) functionalized with mixed thiol ligands were tested as sensing materials. Specifically, the electrical response of gold nanoparticles-based sensors was tested against Hg0vap, H2S, SO2, NH3, and relative humidity (RH) at room temperature. Gold nanoparticles samples were synthesized by the wet reduction method and then deposited as thin films on suitable interdigitated transducers. Electrical conductivity measurements allowed evaluating a semiconducting behavior of the colloids. A selective and reproducible sensing behavior toward Hg0vap was observed in the range 0.1-1.0 ng/mL, allowing simple and reliable resistive devices to be obtained. An irreversible interaction mechanism, based on formation of an Au-Hg direct bond, was observed in the case of isolated AuNPs samples. Interconnected AuNPs exhibited a reversible behavior as assessed by Micro Raman, XRD, XPS, AFM, SEM, and UV-vis and FTIR spectroscopies together with DLS measurements. Broadening of the plasmonic band and an increase in the mean particle size upon contact with Hg0vap was observed. Morphological characterization revealed the formation of aggregates after interaction between Hg0vap and AuNPs. XRD and Micro Raman measurements collected on the nonexposed and Hg-exposed nanoparticles suggest their structural rearrangement at the surface and formation of an Au-Hg alloy with Hg mechanically trapped within the bulk material. The simple and cost-effective fabrication of these sensors has prospect in the future as nanodevices for real-time outdoor air quality monitoring.

Introduction The pathogenic mechanism underlying capsular contracture is still unknown. It is certainly a multifactorial process, resulting from human body reaction, biofilm activation, bacteremic seeding, or silicone exposure. The scope of the present article is to investigate the effect of hypofractionated radiotherapy protocol (2.66 Gy × 16 sessions) both on silicone and polyurethane breast implants. Methods Silicone implants and polyurethane underwent irradiation according to a hypofractionated radiotherapy protocol for the treatment of breast cancer. After irradiation implant shells underwent mechanical, chemical, and microstructural evaluation by means of tensile testing, infrared spectra in attenuated total reflectance mode, nuclear magnetic resonance, and field emission scanning electron microscopy. Results At superficial analysis, irradiated silicone samples show several visible secondary and tertiary blebs. Polyurethane implants showed an open cell structure, which closely resembles a sponge. Morphological observation of struts from treated polyurethane sample shows a more compact structure, with significantly shorter and thicker struts compared with untreated sample. The infrared spectra in attenuated total reflectance mode spectra of irradiated and control samples were compared either for silicon and polyurethane samples. In the case of silicone-based membranes, treated and control specimens showed similar bands, with little differences in the treated one. Nuclear magnetic resonance spectra on the fraction soluble in CDCl3 support these observations. Tensile tests on silicone samples showed a softer behavior of the treated ones. Tensile tests on Polyurethane samples showed no significant differences. Conclusions Polyurethane implants seem to be more resistant to radiotherapy damage, whereas silicone prosthesis showed more structural, mechanical, and chemical modifications.

Strongly hydrophilic gold nanoparticles (AuNPs), functionalized with citrate and L-cysteine, were synthetized and used as Resveratrol (RSV) vehicle to improve its bioavailability. Two different conjugation procedures were investigated: the first by adding RSV during AuNPs synthesis (1) and the second by adding RSV after AuNPs synthesis (2). The two different conjugated systems, namely AuNPs@RSV1 and AuNPs@RSV2 respectively, showed good loading efficiency (&eta, %): &eta, 1 = 80 &plusmn, 5% for AuNPs@RSV1 and &eta, 2 = 20 &plusmn, 3% for AuNPs@RSV2. Both conjugated systems were investigated by means of Dynamic Light Scattering (DLS), confirming hydrophilic behavior and nanodimension (&lt, 2RH&gt, 1 = 45 &plusmn, 12 nm and &lt, 2 = 170 &plusmn, 30 nm). Fourier Transform Infrared Spectroscopy (FT-IR), Synchrotron Radiation induced X-Ray Photoelectron Spectroscopy (SR-XPS) and Near Edge X-ray Absorption Fine Structure (NEXAFS) techniques were applied to deeply understand the hooking mode of RSV on AuNPs surface in the two differently conjugated systems. Moreover, the biocompatibility of AuNPs and AuNPs@RSV1 was evaluated in the concentration range 1.0&ndash, 45.5 &micro, g/mL by assessing their effect on breast cancer cell vitality. The obtained data confirmed that, at the concentration used, AuNPs do not induce cell death, whereas AuNPs@RSV1 maintains the same anticancer effects as the unconjugated RSV.

Olive Mill WasteWater (OMWW) is an important by-product of the Olive Oil production. Its high concentration in Phenolic Compounds (PC) gives OMWW antimicrobial and phytotoxic properties. The aim of this work is to develop a rapid, simple and sustainable method based on the use of gold nanoparticles (AuNPs) chosen to extract PC from OMWW. AuNPs can be used taking advantage of their unique surface properties and high surface/volume ratio. They also offer high stability, easy chemical synthesis and use of water or eco-friendly solvents for their synthesis procedures. Two different stabilizing layers were used on the AuNPs surface: Cysteamine hydrochloride (Cys), and 4,4’’- dithiolterphenyl (TR) obtaining AuNPs-Cys and AuNPs-TR, respectively. The extraction with AuNPs-Cys achieved 70% of the PC present in OMWW, allowing to make the by-product available for land fertilization and giving the possibility to use PC for other aims, as nutraceutical, active packaging, cosmetic or pharmaceutical.

The bifunctional hybrid thioester ligands containing square planar Pt(II) centers 2,7-bis[2-(trans-acetylthio-bis-(tributylphosphine)platinumII)ethynyl]-9,9-didodecyl-9H-fluorene (1) and trans-4,4′-bis[2-(trans-acetylthio-bis-(tributylphosphine)platinumII)ethynyl]stilbene (2) have been prepared in a four-step procedure and used as stabilizing and interconnecting ligands for gold and silver nanoparticles (MNPs), formed in-situ upon deacylation of the MeCOS-Pt(II)-terminal groups. The metallic surface is linked to the Pt(II) centers of the ligands via M-S-Pt(II) bridges. The size of the AuNPs and AgNPs which aggregate into a bi-dimensional network through hybrid metal-organic bridges was controlled by careful choice of synthetic parameters. The morpho-structural features of the nanoparticles, investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and synchrotron radiation induced X-ray photoelectron spectroscopy (SR-XPS), highlighted the linkage between the nanoparticles, featuring diameters below 10 nm.

In this study, two new hexyl bis(pyrazol-1-yl)acetate ligands and related copper(ii) complexes were prepared and fully characterized in the solid state and in solution. Their electronic and molecular structures were investigated by X-ray photoelectron spectroscopy and near edge X-ray absorption; their ligand molecular structural stability upon coordination to copper was also investigated. The Cu(ii) complexes were studied as new catalysts in copper-catalyzed C-H oxidation for allylic functionalization (the Kharasch-Sosnovsky reaction) avoiding the use of any external reducing agents. Using 5 mol% of these catalysts and tert-butylperoxybenzoate as the oxidant, allylic benzoates were obtained in up to 90% yield: the general reaction time was decreased to 6 h and a 5 to 1 ratio of the alkene and tert-butylperoxybenzoate was used to overcome the two most important limitations on their use in chemistry.

Enzyme immobilization on nanocarriers is nowadays considered a useful tool for improving activity and maintaining biocatalysts stability while facilitating their recovery and reuse. In this work we prepared Au and Ag based nanoparticles (AuNPs or AgNPs) stabilized with two different ligands, the organometallic dinuclear complex trans,trans-[dithiodibis(tributylphosphine)diplatinum(II)-4,4′-diethynylbiphenyl] (Pt-DEBP) and the organic dithiol 4,4′-dithiol-biphenyl (BI), able to link the NPs in 3D networks. We investigated the ability of these nanocarriers to interact with a model lipolytic enzyme from Pseudomonas fluorescens and maintain its activity, both in aqueous as well as in organic media. In particular, our results highlighted that the nature of the metal plays a role in enzyme adsorption, while enzyme activity is mostly influenced by the chemistry of the organic spacer. The obtained bioconjugate, between lipase and the most promising carrier, AgNPs-Pt-DEBP, was stable in a wide temperature range (25–55 °C) and it showed good activity retention both in aqueous (50%) as well as in organic media (75%), compared to the lipase used in soluble form.

Silver nanoparticles (AgNPs) are widely used as antibacterial agents and anticancer drugs, but often their low stability limits their mass production and broad applications. The use of niosomes as a carrier to protect and envelop AgNPs gives a new perspective to solve these problems. In this study, AgNPs were functionalized with sodium 3-mercapto-1-propanesulfonate (3MPS) to induce hydrophilic behavior, improving loading in Tween 20 and Span 20 niosomes (NioTw20 and NioSp20, respectively). Entrapment efficiency was evaluated by UV analyses and is around 1&ndash, 4%. Dimensions were investigated by means of dynamic light scattering (DLS) (&lt, 2RH&gt, = 140 &plusmn, 4 nm and &lt, = 251 &plusmn, 1 nm respectively for NioTw20 + AgNPs and NioSp20 + AgNPs) and were compared with those by atomic force microscopy (AFM) and small angle X ray scattering (SAXS) analyses. Stability was assessed in water up to 90 days, and both in bovine serum and human serum for up to 8 h. In order to characterize the local structure of niosomes, SAXS measurements have been performed on Tween 20 and Span 20 empty niosomes and loaded with AgNPs. The release profiles of hydrophilic probe calcein and lipophilic probe Nile Red were performed in HEPES buffer and in human serum. All these features contribute to conclude that the two systems, NioTw20 + AgNPs and NioSp20 + AgNPs, are suitable and promising in the field of biological applications.

In the last decade, many innovative nanodrugs have been developed, as well as many nanoradiocompounds that show amazing features in nuclear imaging and/or radiometabolic therapy. Their potential uses offer a wide range of possibilities. It can be possible to develop nondimensional systems of existing radiopharmaceuticals or build engineered systems that combine a nanoparticle with the radiopharmaceutical, a tracer, and a target molecule, and still develop selective nanodetection systems. This review focuses on recent advances regarding the use of gold nanoparticles and nanorods in nuclear medicine. The up-to-date advancements will be shown concerning preparations with special attention on the dimensions and functionalizations that are most used to attain an enhanced performance of gold engineered nanomaterials. Many ideas are offered regarding recent in vitro and in vivo studies. Finally, the recent clinical trials and applications are discussed.

Gold nanoparticles (AuNPs), which are strongly hydrophilic and dimensionally suitable for drug delivery, were used in loading and release studies of two different copper(I)-based antitumor complexes, namely [Cu(PTA)4]+ [BF4]&minus, (A, PTA = 1, 3, 5-triaza-7-phosphadamantane) and [HB(pz)3Cu(PCN)] (B, HB(pz)3 = tris(pyrazolyl)borate, PCN = tris(cyanoethyl)phosphane). In the homoleptic, water-soluble compound A, the metal is tetrahedrally arranged in a cationic moiety. Compound B is instead a mixed-ligand (scorpionate/phosphane), neutral complex insoluble in water. In this work, the loading procedures and the loading efficiency of A and B complexes on the AuNPs were investigated, with the aim to improve their bioavailability and to obtain a controlled release. The non-covalent interactions of A and B with the AuNPs surface were studied by means of dynamic light scattering (DLS), UV&ndash, Vis, FT-IR and high-resolution x-ray photoelectron spectroscopy (HR-XPS) measurements. As a result, the AuNPs-A system proved to be more stable and efficient than the AuNPs-B system. In fact, for AuNPs-A the drug loading reached 90%, whereas for AuNPs-B it reached 65%. For AuNPs-A conjugated systems, a release study in water solution was performed over 4 days, showing a slow release up to 10%.

International audience; Iron is an essential nutrient for nearly all forms of life, although scarcely available due to its poor solubility in nature and complex formation in higher eukaryotes. Microorganisms have evolved a vast array of strategies to acquire iron, the most common being the production of high-affinity iron chelators, termed siderophores. The opportunistic bacterial pathogen Pseudomonas aeruginosa synthesizes and secretes two siderophores, pyoverdine (PVD) and pyochelin (PCH), characterized by very different structural and functional properties. Due to its chemical similarity with Fe(III), Ga(III) interferes with several iron-dependent biological pathways. Both PVD and PCH bind Fe(III) and Ga(III). However, while the Ga-PCH complex is more effective than Ga(III) in inhibiting P. aeruginosa growth, PVD acts as a Ga(III) scavenger and protects bacteria from Ga(III) toxicity. To gain more insight into the different outcomes of the biological paths observed for the Fe(III) and Ga(III)-siderophore complexes, better knowledge is needed of their coordination geometries that directly influence the metal complexes chemical stability. The valence state and coordination geometry of the Ga-PCH and Fe-PCH complexes has recently been investigated in detail; as for PVD complexes, several NMR structural studies of Ga(III)-PVD are reported in the literature, using Ga(III) as a diamagnetic isosteric substitute for Fe(III). In this work, we applied up-to-date spectroscopic techniques as synchrotron-radiation-induced X-ray photoelectron spectroscopy (SR-XPS) and X-ray absorption fine structure (XAFS) spectroscopy coupled with molecular modeling to describe the electronic structure and coordination chemistry of Fe and Ga coordinative sites in PVD metal complexes. These techniques allowed us to unambiguously determine the oxidation state of the coordinative ions and to gather interesting information about the similarities and differences between the two coordination compounds as induced by the different metal.

In the present work, the study and the performances of an adsorbent material for gaseous mercury employed in different diffusive bodies geometries is presented. The material is based on gold nanoparticles (AuNPs) deposited on quartz fibres filters, suitable for bonding the gaseous mercury through an amalgamation process. Following thermal desorption and analysis, the behavior of different diffusive samplers prototypes was compared. Both indoor and outdoor exposures were carried out in order to evaluate the advantages and shortcomings of the geometries in study at different sites. From the outdoor long-term exposures, a constant uptake rate (Ur), with a low influence coming from the environmental conditions, was observed for the axial geometry, reporting a high coefficient of determination (R2 0.97). Indoor exposures showed a higher reproducibility, along with a higher coefficient of determination (R2 0.99). The presented results allowed us to observe different behaviors coming from two kinds of diffusive samplers designs, showing different adsorption rates and data dispersion. This allowed us to focalize our attention on the most suitable design from these two tested prototypes, for this kind of adsorbent material.

In this work, we show how to control the morphology of femtosecond laser melted gold nanosphere aggregates. A careful choice of both laser fluence and wavelength makes it possible to selectively excite different aggregate substructures to produce larger spherical nanoparticles, nanorods, and nanoprisms or necklace-like 1D nanostructures in which the nanoparticles are interlinked by bridges. Finite integral technique calculations have been performed on the near-field concentration of light in the nanostructures which confirm the wavelength dependence of the light concentration and suggest that the resulting localized high intensities lead to nonthermal melting. We show that by tuning the wavelength of the melting light it is possible to choose the spatial extension of the ensembles of NPs heated thus allowing us to exhibit control over the morphology of the nanostructures formed by the melting process. By a proper combination of this method with self-assembly of chemically synthesized nanoparticles, one can envisage the development of an innovative high-throughput high-resolution nanofabrication technique.

This review provides a broad look on the recent investigations on the synthesis, characterization and physico-chemical properties of noble metal nanoparticles, mainly gold and silver nanoparticles, stabilized with ligands of different chemical nature. A comprehensive review of the available literature in this field may be far too large and only some selected representative examples will be reported here, together with some recent achievements from our group, that will be discussed in more detail. Many efforts in finding synthetic routes have been performed so far to achieve metal nanoparticles with well-defined size, morphology and stability in different environments, to match the large variety of applications that can be foreseen for these materials. In particular, the synthesis and stabilization of gold and silver nanoparticles together with their properties in different emerging fields of nanomedicine, optics and sensors are reviewed and briefly commented.

Fluorescence resonance energy transfer (FRET) system based on functionalized CdTe-guanine and AuNPs-cytosine bioconjugates for the model nucleobase - guanine detection was developed. Thioglycolic acid coated cadmium telluride quantum dots (QDs) conjugated with guanine and sodium 3-mercapto-1-propanesulfonate stabilized gold nanoparticles (AuNPs) capped by cytosine were obtained and fully characterized. Successful formation of the materials was confirmed by UV–Vis, fluorescence and FTIR spectroscopies. Composition of the conjugates was also characterized with elemental analysis and XPS. By employing a guanine-cytosine interaction the bonding between these complementary nucleobases attached to the nanoparticles leads to the formation of QDs-guanine-AuNPs-cytosine assembly, with the size about 7 nm as demonstrated using atomic force microscopy. That enables an effective FRET from functionalized QDs to AuNPs since both, the required distance and the spectral characteristics of donor-acceptor pair were secured. However, it was shown that in the presence of guanine-model molecule which inhibits the interaction between conjugated QDs and AuNPs the FRET is efficiently hampered. Thus monitoring the changes in the restoring fluorescence signal allows to assay the free guanine concentration. Importantly, we have demonstrated the sensitivity and selectivity of the obtained FRET-based system towards guanine. Moreover, in order to confirm the feasibility of the proposed material for nucleobase detection in the real biological samples the developed nanoparticles were also evaluated under simulated urine conditions. The presented strategy of FRET-based conjugated system preparation might be easily used for the development of another nucleobases selective detection and thus opens many possibilities for the determination of biomolecules in the real samples.

The optimization of phenolic compounds extraction from extra virgin olive oil (EVOO) was achieved applying a Response Surface Methodology. A simple and straightforward method for the extraction of phenolic compounds from EVOO has been optimized in the presence of functionalized gold nanoparticles (AuNPs). AuNPs were prepared in the presence of Cysteamine as stabilizing thiol (AuNPs-Cys) in order to obtain a water stable colloidal suspension. The obtained AuNPs-Cys, with mean size of about 10 nm were observed by AFM and used as extracting phase of phenolic compounds from EVOO. External parameters influencing the extraction were studied and a Central Composite Design (CCD) was applied for the optimization. The role of AuNPs-Cys quantity (4–12 mg), mixing and contact time (30–120 min), interfering (olive oil quantity) and phenolic compounds concentration (50–500 ppm) were analyzed. An equation model was obtained by applying CCD, with a high significativity (p < 0.0001) and low coefficient of variation value (CV = 3.14%). Optimization of extraction conditions were modulated up to 99%. This model allows to select the optimal extraction conditions to achieve the best performances and can be widely applied.

A novel type of graphene-like quantum dots, synthesized by oxidation and cage-opening of C60buckminsterfullerene, has been studied as a fluorescent and absorptive probe for heavy-metal ions. The lattice structure of such unfolded fullerene quantum dots (UFQDs) is distinct from that of graphene since it includes both carbon hexagons and pentagons. The basic optical properties, however, are similar to those of regular graphene oxide quantum dots. On the other hand, UFQDs behave quite differently in the presence of heavy-metal ions, in that multiple sensitivity to Cu2+, Pb2+and As(III) was observed through comparable quenching of the fluorescent emission and different variations of the transmittance spectrum. By dynamic light scattering measurements and transmission electron microscope (TEM) images we confirmed, for the first time in metal sensing, that this response is due to multiple complexation and subsequent aggregation of UFQDs. Nonetheless, the explanation of the distinct behaviour of transmittance in the presence of As(III) and the formation of precipitate with Pb2+require further studies. These differences, however, also make it possible to discriminate between the three metal ions in view of the implementation of a selective multiple sensor.

A novel type of graphene-like quantum dots, synthesized by oxidation and cage-opening of C60 buckminsterfullerene, has been studied as a fluorescent and absorptive probe for heavy-metal ions. The lattice structure of such unfolded fullerene quantum dots (UFQDs) is distinct from that of graphene since it includes both carbon hexagons and pentagons. The basic optical properties, however, are similar to those of regular graphene oxide quantum dots. On the other hand, UFQDs behave quite differently in the presence of heavy-metal ions, in that multiple sensitivity to Cu2+, Pb2+ and As(III) was observed through comparable quenching of the fluorescent emission and different variations of the transmittance spectrum. By dynamic light scattering measurements we confirmed, for the first time in metal sensing, that this response is due to multiple complexation and subsequent aggregation of UFQDs. Nonetheless, the explanation of the distinct behaviour of transmittance in the presence of As(III) and the formation of precipitate with Pb2+ require further studies. These differences, however, also make it possible to discriminate between the three metal ions in view of the implementation of a selective multiple sensor.

In this study, we have carried out a characterization of the quenching effect produced by some commonly encountered metal ions (Co2+, Cu2+, Ni2+, Pb2+, Cd2+, As5+) on the photoluminescence of water suspensions of open-cage fullerene quantum dots prepared with a modified Hummers method. The response to heavy-metal ions occurs through a selective quenching of the PL emission and modifications of the absorption spectrum.

The electronic and molecular structure, as well as the chemical nature of noble metal (silver, gold) nanoparticles (AgNPs, AuNPs) stabilized by the negatively charged hydrophilic organic thiol Sodium 3-mercapto-1-propanesulfonate (3-MPS) has been probed combining Synchrotron Radiation-induced X-ray Photoelectron Spectroscopy (SR-XPS) and Surface Enhanced Raman Spectroscopy (SERS). Complementary information about the electronic, chemical and molecular structure is obtained combining SERS and XPS data, allowing to evidence structural similarities and differences related to the noble metal choice. These results coherently suggest the effective 3-MPS chemical absorption onto the nanoparticle surface, which allows to obtain a stable and biocompatible system, suitable for ad hoc further functionalization as required for several applications in biotechnology. It was observed that the NPs molecular overlayer is made up by covalent bonds between thiols and metallic surface atoms, without degradation of the molecule. The metals SR-XPS spectra analysis collected on the silver and gold nanoparticles points out a small surface to volume atomic percent ratio, as a consequence of the NPs size (≥5 nm). Surface-enhanced Raman Scattering (SERS) spectroscopy was employed for the investigation of the NP molecular conjugation. SERS spectra acquired on the capped Ag and AuNPs are in very good agreement and suggest that the same organic layer is covering the NPs. The conjugation with 3-MPS is confirmed by comparing SERS data with the conventional Raman signature of the ligand. The reproducibility of SERS measurements overall points out the high purity and homogeneity of the system and the good integrity of the organic capping layer.

Radiolabeled nanoparticles are promising tools in cancer diagnosis and therapy. Moreover, yttrium-90 (90Y) is a good candidate as suitable β− emitting radioisotope for a new approach to radio-guided surgery (RGS) proposed by some researchers of our group. In this work, we developed new composite nanoparticles, based on polymethylmethacrylate (PMMA), and poly(methylmethacrylate-co-acrylic acid), P(MMA/AA), embedded with yttrium ion (89Y3+), as a first step for the development of new 90Y3+ based nanocomposites. The composite nanoparticles were synthesised by emulsion polymerization technique, in the presence of potassium persulfate (KPS) as radical initiator, toluene as cosolvent, diethylenetriamine penta acetic acid dianhydride (DTPA) as chelating agent, using different MMA/89Y3+ molar ratios. The yttrium doped polymeric nanoparticles were characterized by means of FTIR spectroscopy, SEM-EDX, AFM, and DLS measurements. The influence of experimental parameters, such as cosolvent and reaction time, on morphology and dimension of composite nanoparticles was investigated, and monodispersed nanospheres with diameters from 20 nm to 400 nm were obtained. The composite material was purified and studied by means of DLS to confirm the colloid stability in water solution at different temperatures (25 °C and 37 °C) up to 3 weeks.

Gold nanoparticles, capped by 3-mercapto propane sulfonate (Au-3MPS), were synthesized inside a swollen sulfonated poly(ether ether ketone) membrane (SPEEK). The formation of the Au-3MPS nanoparticles in the swollen sPEEK membrane was observed by spectroscopic and microscopic techniques. The nanocomposite containing the gold nanoparticles grown in the sPEEK membrane, showed the plasmon resonance λmax at about 520 nm, which remained stable over a testing period of three months. The size distribution of the nanoparticles was assessed, and the sPEEK membrane roughness, both before and after the synthesis of nanoparticles, was studied by AFM. The XPS measurements confirm Au-3MPS formation in the sPEEK membrane. Moreover, AFM experiments recorded in fluid allowed the production of images of the Au-3MPSatsPEEK composite in water at different pH levels, achieving a better understanding of the membrane behavior in a water environment; the dynamic hydration process of the Au-3MPSatsPEEK membrane was investigated. These preliminary results suggest that the newly developed nanocomposite membranes could be promising materials for fuel cell applications.