Aero-GaO Nanomaterial Electromagnetically Transparent from Microwaves to Terahertz for Internet of Things Applications.

In this paper, fabrication of a new material is reported, the so-called Aero-GaO or Aerogallox, which represents an ultra-porous and ultra-lightweight three-dimensional architecture made from interconnected microtubes of gallium oxide with nanometer thin walls. The material is fabricated using epitaxial growth of an ultrathin layer of gallium nitride on zinc oxide microtetrapods followed by decomposition of sacrificial ZnO and oxidation of GaN which according to the results of X-ray diffraction (XRD) and X-ray photoemission spectroscopy (XPS) characterizations, is transformed gradually in -GaO with almost stoichiometric composition. The investigations show that the developed ultra-porous Aerogallox exhibits extremely low reflectivity and high transmissivity in an ultrabroadband electromagnetic spectrum ranging from X-band (8-12 GHz) to several terahertz which opens possibilities for quite new applications of gallium oxide, previously not anticipated.

New carbon/ZnO/LiO nanocomposites with enhanced photocatalytic activity.

Our study was focused on the synthesis of photocatalytic materials for the degradation of organic dyes based on the valorization of biomass resources. The biochar resulted from pyrolysis process of cherry pits wastes was activated by CO flow. Activated and inactivated carbon was used to obtain carbon-based photocatalysts impregnated with different zinc salt precursors.

MoS radio: detecting radio waves with a two-dimensional transition metal dichalcogenide semiconductor.

In this paper, we designed, fabricated and tested a microwave circuit based on a MoS self-switching diode. The MoS thin film (10-monolayers nominal thickness) was grown on a 4 inch AlO/high-resistivity silicon wafer by chemical vapor deposition process. The Raman measurements confirm the high quality of the MoS over the whole area of the 4 inch wafer.

Comparative analysis of honey and citrate stabilized gold nanoparticles: In vitro interaction with proteins and toxicity studies.

Gold nanoparticles of comparable size were synthetized using honey mediated green method (AuNPs@honey) and citrate mediated Turkevich method (AuNPs@citrate). Their colloidal behavior in two cell media DMEM and RPMI, both supplemented with 10% FBS, was systematically investigated with different characterization techniques in order to evidence how the composition of the media influences their stability and the development of protein/NP complex. We revealed the formation of the protein corona which individually covers the nanoparticles in RPMI media, like a dielectric spacer according to UV-Vis spectroscopy, while DMEM promotes more abundant agglomerations, clustering together the nanoparticles, according to TEM investigations.

Tunable photoluminescence from interconnected graphene network with potential to enhance the efficiency of a hybrid Si nanowire solar cell.

An interconnected graphene network (IGN) structure with excellent photoluminescence (PL) properties was synthesized using a one-pot microwave-assisted hydrothermal carbonization route. The material exhibited intense and excitation-wavelength dependent PL emission located mainly in the UV-blue light range (300-450 nm). The result demonstrates that graphene networks could also be included in the emerging class of tunable PL carbon nanomaterials.

Significance Testing and Multivariate Analysis of Datasets from Surface Plasmon Resonance and Surface Acoustic Wave Biosensors: Prediction and Assay Validation for Surface Binding of Large Analytes.

In this study, we performed uni- and multivariate data analysis on the extended binding curves of several affinity pairs: immobilized acetylcholinesterase (AChE)/bioconjugates of aflatoxin B₁(AFB₁) and immobilized anti-AFB₁ monoclonal antibody/AFB₁-protein carriers. The binding curves were recorded on three mass sensitive cells operating in batch configurations: one commercial surface plasmon resonance (SPR) sensor and two custom-made Love wave surface-acoustic wave (LW-SAW) sensors. We obtained 3D plots depicting the time-evolution of the sensor response as a function of analyte concentration using real-time SPR binding sensograms.

Surface Morphology Effects on Photocatalytic Activity of Metal Oxides Nanostructured Materials Immobilized onto Substrates.

Structure, shape and surface morphology of the material are directly determined by the substrate and growth method used for material fabrication of nanostructured metal oxides. Those characteristics play a crucial role in the photocatalytic activity of the material. This paper presents a short review of some of the most recent relevant publications regarding pure and doped nanostructured metal oxides used for photocatalytic applications focusing on the structure, shape and surface morphology of the material effects on photocatalytic activity.

Electromagnetic energy harvesting based on HfZrO tunneling junctions.

HfZrO ferroelectrics with a thickness of 6 nm were grown directly on Si using atomic layer deposition, top and bottom metallic electrodes being subsequently deposited by electron-beam metallization techniques. Depending on the polarity of the ±10 V poling voltages, the current-voltage dependence of these tunneling diodes shows a rectifying behavior for different polarizations, the ON-OFF ratio being about 10. Because the currents are at mA level, the HfZrO tunneling diodes coupled to an antenna array can harvest electromagnetic energy at 26 GHz (a bandwidth designated for internet of things), with a responsivity of 63 V W and a NEP of 4 nW/Hz.

Specific detection of stable single nucleobase mismatch using SU-8 coated silicon nanowires platform.

Novel microarray platform for single nucleotide polymorphisms (SNPs) detection has been developed using silicon nanowires (SiNWs) as support and two different surface modification methods for attaining the necessary functional groups. Accordingly, we compared the detection specificity and stability over time of the probes printed on SiNWs modified with (3-aminopropyl)triethoxysilane (APTES) and glutaraldehyde (GAD), or coated with a simpler procedure using epoxy-based SU-8 photoresist. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used for comparative characterization of the unmodified and coated SiNWs.

Engineering Graphene Quantum Dots for Enhanced Ultraviolet and Visible Light p-Si Nanowire-Based Photodetector.

In this work, a significant improvement of the classical silicon nanowire (SiNW)-based photodetector was achieved through the realization of core-shell structures using newly designed GQDs via simple solution processing. The poly(ethyleneimine) (PEI)-assisted synthesis successfully tuned both optical and electrical properties of graphene quantum dots (GQDs) to fulfill the requirements for strong yellow photoluminescence emission along with large band gap formation and the introduction of electronic states inside the band gap. The fabrication of a GQD-based device was followed by systematic structural and photoelectronic investigation.

Pan-European inter-laboratory studies on a panel of in vitro cytotoxicity and pro-inflammation assays for nanoparticles.

The rapid development of nanotechnologies and increased production and use of nanomaterials raise concerns about their potential toxic effects for human health and environment. To evaluate the biological effects of nanomaterials, a set of reliable and reproducible methods and development of standard operating procedures (SOPs) is required. In the framework of the European FP7 NanoValid project, three different cell viability assays (MTS, ATP content, and caspase-3/7 activity) with different readouts (absorbance, luminescence and fluorescence) and two immune assays (ELISA of pro-inflammatory cytokines IL1-β and TNF-α) were evaluated by inter-laboratory comparison.

Molybdenum disulphide and graphene quantum dots as electrode modifiers for laccase biosensor.

A nanocomposite formed from molybdenum disulphide (MoS2) and graphene quantum dots (GQDs) was proposed as a novel and suitable support for enzyme immobilisation displaying interesting electrochemical properties. The conductivity of the carbon based screen-printed electrodes was highly improved after modification with MoS2 nanoflakes and GQDs, the nanocomposite also providing compatible matrix for laccase immobilisation. The influence of different modification steps on the final electroanalytical performances of the modified electrode were evaluated by UV-vis absorption and fluorescence spectroscopy, scanning electron microscopy, transmission electron microscopy, X ray diffraction, electrochemical impedance spectroscopy and cyclic voltammetry.

Design, fabrication and characterization of a low-impedance 3D electrode array system for neuro-electrophysiology.

Recent progress in patterned microelectrode manufacturing technology and microfluidics has opened the way to a large variety of cellular and molecular biosensor-based applications. In this extremely diverse and rapidly expanding landscape, silicon-based technologies occupy a special position, given their statute of mature, consolidated, and highly accessible areas of development. Within the present work we report microfabrication procedures and workflows for 3D patterned gold-plated microelectrode arrays (MEA) of different shapes (pyramidal, conical and high aspect ratio), and we provide a detailed characterization of their physical features during all the fabrication steps to have in the end a reliable technology.

Nanostructure and internal strain distribution in porous silicon.

Porous silicon (PS) layers with different degrees of porosity have been fabricated and their nanostructure has been investigated using complementary methods as FE-SEM (field emission scanning electron microscopy), SAXS (small-angle X-ray scattering), and Raman spectroscopy. Correlation of these results with strain analyses is also required for envisaged applications in MEMS technology. Symmetrical and asymmetrical rocking curves obtained by high-resolution X-ray diffraction completed with reciprocal space maps (RSMs) explain the features observed in Raman spectra: the PS film in-depth contains two layers-bulk and highly strained superficial layer, between them being a graded strain layer.

Detection of human papilloma viruses using nanostructurated silicon support in microarray technology.

In a typical microarray experiment, DNA is arrayed on a solid substrate as spots, the array being probed with a sample or a capture molecule of interest and the interaction monitored through different detection methods. The present study evaluates the possibility to use micro-array technology to genotype samples with Human Papilloma Viruses (HPV). The performance of DNA microarrays strongly depend on their surface properties.

Nanostructured silicon particles for medical applications.

Porous silicon (PS) which has different properties from the bulk material due to the quantum confinement effects is beside other physical properties (e.g., light emitting) bioactive or even bioresorbable.