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Copper is efficient, has a high conductivity (5.8 × 107 S/m), and is cost-effective. The use of copper-based catalysts is promising for the electrocatalytic reduction of nitrates. This work aims to grow and characterize copper micro-crystals on Screen-Printed Electrodes (SPEs) for NO3− reduction in water. Copper micro-crystals were grown by cyclic voltammetry. Different cycles (2, 5, 7, 10, 12, 15) of copper electrodeposition were investigated (potential ranges from −1.0 V to 0.0 V, scan rate of 0.1 V s−1). Electrodeposition generated different morphologies of copper crystals on the electrodes, as a function of the number of cycles, with various performances. The presence of numerous edges and defects in the copper micro-crystal structures creates highly reactive active sites, thus favoring nitrate reduction. The manufactured material can be successfully employed for environmental applications. [ABSTRACT FROM AUTHOR]

The progressive increase in nitrate's (NO3−) presence in surface and groundwater enhances environmental and human health risks. The aim of this work is the fabrication and characterization of sensitive, real-time, low-cost, and portable amperometric sensors for low NO3− concentration detection in water. Copper (Cu) micro-flowers were electrodeposited on top of carbon screen-printed electrodes (SPCEs) via cyclic voltammetry (with voltage ranging from −1.0 V to 0.0 V at a scan rate of 0.1 V s−1). The obtained sensors exhibited a high catalytic activity toward the electro-reduction in NO3−, with a sensitivity of 44.71 μA/mM. They had a limit of detection of 0.87 µM and a good dynamic linear concentration range from 0.05 to 3 mM. The results were compared to spectrophotometric analysis. In addition, the devices exhibited good stability and a maximum standard deviation (RSD) of 5% after ten measurements; reproducibility, with a maximum RSD of 4%; and repeatability after 10 measurements with the RSD at only 5.63%. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a diffused neurodegenerative disorder affecting people in advanced age causing loss of memory and dementia. Nowadays, diagnosis and treatment of AD are still challenging due to the lack of diagnostic systems that allow for an early and reliable diagnosis and therapy monitoring. Moreover, conventional strategies for AD diagnosis are based on brain imaging techniques that are invasive and expensive for early and massive screening. Phage display approach, using engineered phage probe for direct amyloid‐β (Aβ)‐autoantibodies detection, overcome these limitations leading to the possibility of safe and low‐cost screening. Moreover, the combination with silicon technology further improves the easiness of diagnosis due to the portability of devices and the integration of sensitive transduction signals. In this work, an innovative silicon‐based sensing technology is reported detecting Aβ‐autoantibodies, specifically Immunoglobulin G (IgG), in human sera by engineered M13‐phage probes (ADPP). The strategy hinges on a bio‐surface that is integrated on top of a silicon biosensor. Thanks to phages probes exposing Aβ‐mimic peptides, this chip can capture and reveal Aβ‐autoantibodies, discriminating between healthy and AD conditions. The surface chemistry is morphologically and chemically characterized and the phage‐based biosensor ability to recognise Aβ‐autoantibodies is proved by transduction with enzyme‐linked anti‐M13 antibodies. [ABSTRACT FROM AUTHOR]

Pyroelectric materials are very promising for thermal energy harvesting applications. To date, lead‐based systems are the foremost studied materials in this field. A facile and simple metal organic chemical vapor deposition route is applied for the fabrication of lead‐free, high quality, epitaxial Bi(1−x)DyxFeO3 (x = 0, 0.06, 0.08, 0.11) thin films deposited on conductive SrTiO3:Nb (100) single crystal substrates. The films are studied by structural, morphological, compositional, and functional characterization. The correlation between the Dy‐doping amount and the dielectric properties is thoroughly investigated. Unipolar polarization–electric field loops and permittivity measurements show the important impact of Dy on ferroelectric, dielectric, and pyroelectric properties. Dy doping increases considerably the dielectric response, but much more the pyroelectric coefficient, up to a concentration of 8% Dy. The films are self‐poled, which is an ideal situation for pyroelectric applications. The best figure of merit for pyroelectric energy harvesting, FE, is 82 J m−3 K−2, showing a factor increase of 2.6 as compared to the undoped film of the sample series. It constitutes a factor 4.5 improvement as compared to previous results obtained on BiFeO3 based thin films. [ABSTRACT FROM AUTHOR]

We explore a strategy to counteract aging issues in TiO2/aluminium-doped ZnO bi-layers used in hybrid solar cells photo-anodes, mainly related to Zn diffusion in the TiO2 matrix. Different Ti4+ and Zn2+ local structures within the anatase grains and along the film thickness were found as a function of post-deposition annealing treatments in the range between 200 °C and 500 °C by synchrotron radiation extended x-ray absorption fine structure analyses. In particular, in the 500 °C-treated sample, diffusion of zinc species along the TiO2 grain-boundaries has been observed with aging (3 years). In contrast, a mild thermal budget at 200 °C favours a proper atomic arrangement of the zinc-containing anatase lattice which reduces Zn diffusion, thus guaranteeing a good stability with aging. [ABSTRACT FROM AUTHOR]

Metal organic chemical vapor deposition (MOCVD) is exploited as a synthetic route to produce Ba and Ti co-doped BiFeO3 thin films. A facile approach based on a molten multi-component source, consisting of a Bi(phenyl)3, Fe(tmhd)3, Ba(hfa)2·tetraglyme and Ti(tmhd)2(O-iPr)2 (phenyl = –C6H5, H-tmhd = 2,2,6,6-tetramethyl-3,5-heptandione; O-iPr = iso-propoxide; H-hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione; tetraglyme = CH3O(CH2CH2O)4CH3) mixture, is applied for the MOCVD based fabrication of doped BiFeO3 films on SrTiO3:Nb(100) substrates. The applied characterization techniques, such as X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM), provide a suitable correlation between processing parameters/precursor mixtures and the nature of the deposited films, in terms of the formation of solid solutions of the type Bi(1−x)BaxFe(1−y)TiyO3vs. the formation of Bi(1−x)BaxFeO3/Bi(1−x)BaxFe(1−y)TiyO3 nanocomposite films. Piezoresponse force microscopy (PFM) is applied to correlate the nanostructure/composition and piezoelectric/ferroelectric properties. [ABSTRACT FROM AUTHOR]

A Si(100) surface featuring molecular recognition properties is obtained by covalent functionalization with a tetraphosphonate cavitand (Tiiii), which is able to complex positively charged species. The recognition properties of the Si-Tiiii surface are shown through two independent analytical methods during the course of reversible complexation-guest exchange-decomplexation cycles with specifically designed ammonium and pyridinium salts.