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In this work we report the possibility to obtain a high refractive index grid anode directly on the substrate surface by fabricating a relatively large-area photonic crystal (PC) structure using the combinations of electron beam lithography (EBL) and focused ion beam (FIB) techniques. The performance of the realized photonic crystal (PC) structure were enhanced by milling the ITO layer until the glass substrate and by removing the further refractive index jump between the PC and the substrate. The good properties of highly conductive poly(3,4 ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), ensured a continuous path for the current and a high refractive index jump for the PC structure by filling the holes in the PC structure.

Technologies based on plasmonic nanostructures are a rapidly growing field that aims to be a valid alternative to conventional diagnostic tools. One of the main goals in their technological development consists of the design of systems for sensitive and specific detection of pathogens in water. Among these, rotaviruses represent the main cause of childhood viral gastroenteritis in humans. In this work, we design functionalized plasmonic label-free nanosensors based on localized surface plasmon resonance (LSPR) sensing to detect ultralow concentrations of rotavirus. We demonstrate the possibility of detecting in a specific way amounts lower than 1 × 103 plaque forming unit (PFU)/mL of the Rotavirus in water using a very low sample volume (2 μL). These results together with those obtained in our specificity tests performed with two different viruses (bovine herpesvirus, BHV1; and equine viral arteritis, EVA) confirm that our device is very promising to develop a rapid, simple, very sensitive, and specific immunoassay for detection of rotavirus. To the best of our knowledge, this is the first time that LSPR nanobiosensing has been used for the sensitive and specific detection of rotavirus. [ABSTRACT FROM AUTHOR]

In this paper, we report on novel iso-Y-shaped-nanopillar based photonic crystals (PCs) engineered for plasmonic lab-on-a-chip advanced diagnostics. The iso-Y shaped units are selected on the basis of their plasmonic properties, analyzed numerically and experimentally. We show that by accurately choosing the nanopillar shape, dimensions and their geometrical disposal it is possible to obtain efficient optical 2D structures for biomolecule detection by high-sensitive localized surface plasmonic resonance (LSPR). In particular, an assay is realized by using bovine serum albumin (BSA), a widely recognized model for biosystem studies. BSA was simply deposited on a self-assembled monolayer (SAM) of 4-mercaptobenzoic acid (4-MBA) previously grown-up on the plasmonic substrate. We demonstrate that the geometries considered allow the design of LSPR nano-assays working in the visible-NIR region based on both intensity interrogation and the resonance peak shift permitting the sensing of BSA with a limit of detection in the order of picomoles (LOD = 233 pM). [ABSTRACT FROM AUTHOR]

Results about induced spatial modulation of critical current density in niobium based Josephson devices by a selective radiation heating are presented. The localized heating inside a single circuit element with a good spatial resolution (less than 1 μm) is made possible by depositing a carbon film on the desired region exploiting the larger absorbance coefficient of carbon (close to 1) with respect to niobium (about 0.2). Measurements of critical current as a function of the external magnetic field on high quality Josephson junctions at T = 4.2 K evidenced that the critical current density was changed only in the absorber covered region, leaving unchanged the critical current density outside that region and ensuring the capability to locally modify the Josephson critical current density. The experimental data have been compared with theoretical predictions obtained by using a suitable junction barrier model based on step-like barrier shape. Such results are very interesting in view of applications in quantum computing, Majorana fermions detection, and superconducting magnetic sensors. [ABSTRACT FROM AUTHOR]

Two different metamaterial-liquid crystal structures are fabricated with the metamaterials as liquid crystal (LC) and semiconductor nanorods doped LC alignment layers. E-beam lithography was used to pattern the electron-sensitive polymer one-dimensional photonic crystal (PC) structures. The nanostructured aligning surfaces have been characterized by scanning electron microscopy. The PCs-Dispersed Liquid Crystalline Metamaterials have been investigated through polarized optical microscopy. The threshold voltage and response times for the undoped and doped nematic LCs in the glass cells are measured as a function of the applied external electric field. [ABSTRACT FROM PUBLISHER]

A thermal annealing technique for Nb/Al–AlOx/Nb Josephson devices based on laser heating is presented. This technique allows “locally” modifying the Josephson critical current density, which is not possible using standard procedures based on oven or hot plate heating. In fact, the heating of a single circuit element with a good spatial resolution is possible. At room temperature, the selected junction is exposed to a focused Ar+ laser beam aligned by an optical system. A thermographic imaging allows controlling the temperature distribution on the whole chip. Experimental results on high quality Josephson junction measured in liquid helium have shown a continuous reduction of the critical current density up to about 40%. Neighboring junctions have not exhibited any measurable change ensuring the capability to locally modify the Josephson critical current density. As first application, the present technique has been employed to recover noisy dc superconducting quantum interference device magnetometers with nonoptimal critical current values obtaining a reduction of the spectrum density of magnetic field noise from about 30 to 2.5 fT/Hz1/2. [ABSTRACT FROM AUTHOR]

An innovative soil solarization method working like a solar hot panel, was applied on a soil previously amended with compost, to test for sanitation efficiency in controlling soil-borne fungi and preserving soil chemical and biological fertility. Soil was sprayed on surface with biodegradable black liquid consisting in a polysaccharide gel-carbon black mixture then covered with a clear plastic film. Two concurrent experiments were carried out under tunnel. In the first one, thirty-days long solarization cycles were carried out with the aim to measure thermal efficacy and survival of three fungal pathogens by comparing the innovative to the conventional solarisation. The innovative solarization improved sanitation with respect to Sclerotinia sclerotiorum , Fusarium oxysporum f. sp. melonis and Plectosphaerella cucumerina , it increased soil maximum and minimum temperatures, as well as the sum of hours conventionally considered effective for fungi disinfection (>37 °C). In the second experiment, carried out in 2014–2016, the innovative solarization was scheduled insight a crop sequence of leafy vegetables for the ready-to eat salads sector and the efficacy of organic amendment for soil fertility preservation was tested too. A yearly organic amendment by olive husk compost at rate of 15 t ha −1 was applied before innovative solarization. This approach was compared to i) soil disinfection by standard farm solarization plus mineral fertilization; ii) control consisting in soil not solarized nor fertilized. K 2 SO 4 -extractable C and N, microbial biomass and enzymatic activities associated with biogeochemical cycles of C, N, P, S, were monitored before and after solarization. Results showed that soil amendment associated to innovative solarization almost cancelled detrimental effects of solarization on biochemical activities, increased soil organic C content of 2 g kg −1 and increased the yield of leafy vegetables by 30% compared to both control not treated and standard solarization. [ABSTRACT FROM AUTHOR]