Eleonora Marconi

Gold nanorods (AuNRs) were synthesized and optimized with the aim of obtaining strongly hydrophilic nanomaterials, suitable as a drug delivery system (DDS) for copper-based drugs. After careful purification, AuNRs were characterized by ultraviolet–visible–near-infrared spectroscopy (UV–Vis–NIR), showing two typical localized surface plasmon resonance (LSPR) bands in the range 550–750 nm. Fourier Transform Infrared (FT-IR) and high-resolution X-ray photoelectron (HR-XPS) spectroscopies verified the surface functionalization. Transmission electron microscopy (TEM) showed AuNRs with regular shape and size, with an aspect ratio (AR) of 2.6. Dynamic Light Scattering (DLS) measurements confirmed the size and the stability in water for up to 3 months. The AuNRs were conjugated with copper(I) drugs, i.e., [Cu(PTA)₄]BF₄ (PTA = 1,3,5-triaza-7-phosphadamantane). The drug loading procedures and efficiency were optimized, and the best loading was η (%) = 50 ± 7%. The non-covalent interactions of the Cu(I) complex with the AuNRs were studied by means of UV–Vis–NIR, ζ-potential, HR-TEM, FT-IR, synchrotron radiation-induced X-ray photoelectron (SR-XPS), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy measurements. The MTT assay performed on Vero E6 cells showed that AuNRs and AuNR-Cu(I) conjugates had no significant effect on cell viability, being biocompatible, causing a reduction in cell viability only after prolonged exposure.

This paper presents an original method for synthesizing Zn-doped mesoporous silica (KCC-1) via a one-pot microemulsion method followed by hydrothermal treatment. Zn incorporation into the silica matrix was achieved by varying Zn/Si molar ratios from 1% to 8%. The Zn-doping effect on KCC-1 morphological and structural properties was investigated using several characterization techniques, providing new insights into the Zn-doping behavior and coordination environment. X-ray fluorescence (XRF) spectra confirmed the stoichiometric doping of silica nanoparticles for samples obtained with a precursor concentration of 1%, 3%, and 6%. An attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy highlighted that Zn was included into the KCC-1 matrix rather than chemically adsorbed onto the surface. Scanning electron microscopy (SEM) images clearly showed that a low Zn content preserves the KCC-1 fibrous morphology. An X-ray diffraction (XRD) analysis confirmed the amorphous nature of the doped nanoparticles, suggesting a structural disorder of the silica framework at higher Zn concentrations. X-ray photoelectron spectroscopy (XPS) revealed that Zn–(OH)₂ bonds increased at a 6% Zn/Si molar ratio, confirming the disordered inclusion of Zn at this doping limit. X-ray absorption near-edge structure (XANES) data revealed that in Zn-doped silica at 3% and 6%, Zn primarily exists in a coordination state similar to zinc-silicates and the amorphous Zn-hydroxyapatite-like phase.

The widespread use of glyphosate for weed control in agricultural, silvicultural, and urban areas worldwide is causing concerns about its potential toxicity and mobility in environment. Consequently, there is a pressing need to develop treatment processes to mitigate the effects of glyphosate, its metabolites, and/or coadjutants on the environment. Titanium dioxide nanoparticles (TNPs), among the most widely used engineered NPs, have recently attracted significant attention for glyphosate adsorption. In this study, TNPs were obtained through two synthesis procedures working at low temperatures and with a reduced amount of organic solvent. The first involves a polycondensation reaction of alkoxide precursors at 70 °C in a water‐in‐oil (W/O) microemulsion with a 1 : 1 volume ratio, employing cetylpyridinium bromide (CPB) as a cationic surfactant to obtain crystalline TNPs. In the second method, two resins characterized by different morphologies were used as a template, to grow amorphous TNPs. Glyphosate adsorption tests performed at different pH values, i.e. 4.0 and 8.5, revealed that the analyte is more effectively retained by the TNPs at pH 4.0, at which TiO₂ surfaces are positively charged and better interact with anionic glyphosate species. TNPs obtained via microemulsion using titanium alkoxide as the precursor and calcined at 450 °C showed excellent performance, removing from the solution nearly 99% of glyphosate, even at pH 8.5. Similarly, resin composites work efficiently in eliminating a high percentage of glyphosate, taking advantage of a better dispersion of amorphous TiO₂ and a higher surface‐to‐volume ratio. This study demonstrates the effective capture of glyphosate by titanium dioxide nanoparticles, highlighting some factors contributing to the adsorption ability, and their potential as a unique tool for adsorbing glyphosate in a one‐pot process.

In this study, we compared two low-temperature synthesis procedures for the large-scale production of titania nanoparticles (NPs). The first takes place in an aqueous medium with an acidic environment, by using a triblock polymer surfactant (Pluronic 123). The second involves a polycondensation reaction of alkoxide precursors at 70 °C in a water-in-oil (W/O) microemulsion with a volume ratio of 1:1, using cetylpyridinium bromide (CPB) as a cationic surfactant. The morphological and structural characterization of the samples was carried out through Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The photoactivity of the nanostructured titania was evaluated by measuring the photodegradation of Methylene Blue (MB). The solvent-free synthetic approach provided spherical titania nanoparticles mainly constituted by rutile crystallites with a very good synthetic yield. However, the photodegradation rate of MB for such titania nanoparticles ranges from 30 % to 40 %, after 1h under solar irradiation. Conversely, titania nanoparticles obtained through microemulsion synthesis show a photodegradation rate of more than 90 % comparable to titania P25. This high-yield synthesis leads to the formation of TiO2 nanoparticles characterized by small crystallite aggregates (rutile and anatase).

Development of novel and inexpensive X-ray detectors is of key importance for numerous applications, such as dosimetry in nuclear and medical facilities, diagnostics in cultural heritage, and homeland security. Solution-processed materials are being investigated as novel x-ray sensing materials, with constant improvements that are rapidly approaching commercial standards. Here, we demonstrate a detector based on PbS colloidal quantum dots (QD) fabricated in air with simple drop-casting techniques on a Si substrate with pre-patterned Au interdigitated electrodes. The device showed good linearity in the tested dose range and a maximum sensitivity value of 2370 µC Gy⁻¹ cm⁻¹, which is higher than typically reported values for commercial a-Se and poly-CZT detectors.

Mesoporous silica nanoparticles (MSNPs) are currently used in different fields like catalysis, nanomedicine, and conservation science, taking advantage of their high surface area. Here, we synthesized and functionalized mesoporous dendritic fibrous nanoparticles to realize a smart delivery system of protective agents for metals. Different MSNPs were obtained via the microemulsion method followed by a hydrothermal or refluxing treatment at different w/o ratios, times, and temperatures. Dendritic spherical silica nanoparticles with specific features such as an appropriate size (450 nm), a very large surface area (600 m² g⁻¹), and a high yield synthesis (86%) were selected for surface modification. The fiber surface of the selected MSNPs was functionalized with 3-aminopropyl triethoxysilane (3-APTES). 3-APTES works as a pH-driven “nanogate”, suppressing the immediate leakage of the total guest molecule load and modulating the release as a function of pH conditions. Surface-modified MSNPs were tested as a reservoir of the most diffused corrosion inhibitors: Mercaptobenzothiazole (MBT) and 1H-Benzotriazole (BTA); their release properties were studied in solutions with pH = 4 and 7. Functionalized and non-functionalized MSNPs showed a good loading efficiency of guest molecules (34–64%) and a pH-dependent release of the corrosion inhibitors on a timescale of several hours.

The nanorod morphology of the CeO₂ support has been recognized as more beneficial than other morphologies for catalytic activity in the dry reforming of methane. Ni/nanorod-CeO₂ catalysts with different Ni contents were prepared by one-pot hydrothermal synthesis. Samples were characterized by X-ray diffraction (XRD), H₂-temperature-programmed reduction (H₂-TPR), H₂-temperature-programmed desorption (H₂-TPD), field emission scanning electron microscopy/energy dispersive spectroscopy (FE-SEM/EDS), Brunauer–Emmet–Teller (BET) and Barrett–Joyner–Halenda (BHJ) analysis. The effect of Ni content on the size and the intrinsic strain of ceria was analyzed by the Size–Strain plot and Williamson–Hall plot of XRD data. The average Ni particle size and Ni dispersion were determined by H₂-TPD. XRD and H₂-TPR analysis revealed a strong Ni–support interaction that limited nickel sintering. The activity for the dry reforming of methane was tested with the stoichiometric mixture CO₂:CH₄:N₂:He = 20:20:20:140, gas hourly space velocity (GHSV) = 300 L g⁻¹ h⁻¹, and temperatures in the range of 545–800 °C. The turnover frequency (TOF) value increased linearly with the average Ni particle size in the range of 5.5–33 nm, suggesting the structure sensitivity of the reaction. Samples with Ni loading of 4–12 wt.% showed high H₂/CO selectivity and stability over time on stream, whereas the sample with a Ni loading of 2 wt.% was less selective and underwent rapid deactivation. Only a small amount of nanotubular carbon was observed by FE-SEM after the time-on-stream experiment. Deactivation of the low-Ni-content sample is ascribed to the easier oxidation of the small Ni particles.