Bottom- and top-contact organic thin film transistors (OTFTs) were fabricated, using poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly[2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene] (PBTTT-C16) as p-type channel semiconductors. Four different types of OTFTs were fabricated and investigated as gas sensors against three volatile organic compounds, with different associated dipole moments. The OTFT-based sensor responses were evaluated with static and transient current measurements. A comparison between the different architectures and the relative organic semiconductor was made.

We will report on the design and realization of optoacoustic sensors based on commercial quantum cascade lasers for environmental analysis applications. Different configurations will be described: i) sensors based on resonant photoacoustic cells, a "standard" H cell and an innovative T-cell; ii) sensor based on quartz enhanced photoacoustic spectroscopy. We will analyze the results obtained in the detection of nitric oxide.

Among the metal oxide semiconductors, ZnO has been widely investigated as a channel material in thin-film transistors (TFTs) due to its excellent electrical properties, optical transparency and simple fabrication Via solution-processed techniques. Herein, we report a solution-processable ZnO-based thin-film transistor gated through a liquid electrolyte with an ionic strength comparable to that of a physiological fluid. The surface morphology and chemical composition of the ZnO films upon exposure to water and phosphate-buffered saline (PBS) are discussed in terms of the operation stability and electrical performance of the ZnO TFT devices. The improved device characteristics upon exposure to PBS are associated with the enhancement of the oxygen vacancies in the ZnO lattice due to Na+ doping. Moreover, the dissolution kinetics of the ZnO thin film in a liquid electrolyte opens the possible applicability of these devices as an active element in "transient" implantable systems.

Gold (Au) nanoparticles stabilized on metal oxide supports offer superior catalytic activity and recyclability in organic catalysis. We report for the first time synthesis of indium oxide stabilized gold (Au@In2O3) nanocatalysts using an electrochemical procedure and their application in homocoupling of arylboronic acids. In2O3 nanoparticles prepared via sol-gel process are subjected to sacrificial anode electrolysis (SAE) under inert condition for electrodeposition of nano Au on In2O3. Thus Au@In2O3 nanoparticles obtained are thermally annealed at high temperature to partially oxidize Au and to remove any surfactants. XPS results show the existence of both elemental (nano Au) and cationic (Au3+) species in Au@In2O3 nanocatalysts, while SEM images confirm the presence of nanoscale Au (< 10 nm) particles on In2O3 surface. Au@In2O3 nanocatalysts are tested for arylboronic acids homocoupling under different conditions and it is found that they are highly active in organic medium with K2CO3 base and demonstrate excellent conversion (> 97%) and selectivity (> 98%). The catalyst recyclability and performance towards differently substituted arylboronic acids is also studied and a plausible mechanism of action is proposed. (C) 2014 Elsevier B.V. All rights reserved.

In the present study, Au-surfactant core-shell colloidal nanoparticles (NPs) with controlled dimension and composition were synthesized by sacrificial anode electrolysis. Transmission electron microscopy (TEM) revealed that Au NPs core diameter is between 8 and 12 nm, as a function of the electrosynthesis conditions. Moreover, surface spectroscopic characterization by X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of nanosized gold phase. Controlled amounts of Au NPs were then deposited electrophoretically on carbon nanotube (CNT) networked films. The resulting hybrid materials were morphologically and chemically characterized using TEM, SEM (scanning electron microscopy) and XPS analyses, which revealed the presence of nanoscale gold, and its successful deposition on CNTs. Au NP/CNT networked films were tested as active layers in a two-pole resistive NO2 sensor for sub-ppm detection in the temperature range of 100-200 °C. Au NP/CNT exhibited a p-type response with a decrease in the electrical resistance upon exposure to oxidizing NO2 gas and an increase in resistance upon exposure to reducing gases (e.g. NH3). It was also demonstrated that the sensitivity of the Au NP/CNT-based sensors depends on Au loading; therefore, the impact of the Au loading on gas sensing performance was investigated as a function of the working temperature, gas concentration and interfering gases.

The primary aim of the present work was to evaluate the in vitro uptake of 6-Coumarin (6COUM) loaded solid lipid nanoparticles (SLN) by two gilthead seabream (Sparus aurata L.) cell types: an established cell line (SAF-1 cells) and the primary cultures of head-kidney (HK)--the main haemopoietic organ in fish, equivalent to mammalian bone marrow--leucocytes. For this purpose, after the physicochemical characterization of SLN, the uptake by those immunocompetent fish cells was evaluated using flow cytometry and confocal microscopy. Concomitantly, the uptake of 6-COUM loaded {SLN} was compared with that achieved with 6-COUM loaded pectin microparticles (MPs), which were selected as a competitor of the delivery carriers. After {SLN} and {MP} physicochemical characterization, the results demonstrated that SAF-1 cells were able to internalize high percentages of 6-COUM {SLNs} when incubated for 4, 8 and 24&xa0;h, with the highest {SLN} concentration tested (10&xa0;?g/ml). The ability of {HK} leucocytes to internalize {SLN} was also found to vary depending on both incubation time and {SLN} concentration. The highest values of {HK} leucocytes internalizing {SLN} particles (around 16%) were detected at the maximum {SLN} concentration (20&xa0;?g/ml) at incubation times of 4 or 8&xa0;h. Conversely, {HK} leucocytes were unable to internalize {MPs} at any tested concentration and incubation time. A possible mechanism explaining the uptake into cells is proposed. The present work constitutes the first approximation to consider {SLN} as nanocarriers for delivering biologically active substances to fish.

Several spectroscopic methods based on mid-infrared quantum cascade lasers for the ultrasensitive detection of nitric oxide have been developed with detection limit in ppbv and sub-ppbv range. We will describe here a selection of the most effective techniques, i.e., laser absorption spectroscopy, cavity-enhanced spectroscopy, photoacoustic spectroscopy, and Faraday modulation spectroscopy. For each technique, advantages and drawbacks will be underlined.

Organic field-effect transistors including a functional biorecognition interlayer, sandwiched between the dielectric and the organic semiconductor layers, have been recently proposed as ultrasensitive label-free biosensors capable to detect a target molecule in the low pM concentration range. The morphology and the structure of the stacked bilayer formed by the protein biointerlayer and the overlying organic semiconductor is here investigated for different protein deposition methods. X-ray scattering techniques and scanning electron microscopy allow us to gather key relevant information on the interface structure and to assess target analyte molecules capability to percolate through the semiconducting layer reaching the protein deposit lying underneath. Correlations between the structural and morphological data and the device analytical performances are established allowing us to gather relevant details on the sensing mechanism and further improving sensor performances, in particular in terms of sensitivity and selectivity. © 2014 American Chemical Society.

Metal nanomaterials have an emerging role in surface-assisted laser desorption ionisation-mass spectrometry (SALDI-MS) providing a useful tool to overcome some limitations intrinsically related to the use of conventional organic matrices in matrix-assisted LDI-MS. In this contribution, the possibility to use a stainless-steel-supported gold nanoparticle (AuNP) film as a versatile platform for SALDIMS was assessed. A sacrificial anode electrosynthetic route was chosen in order to obtain morphologically controlled core-shell AuNPs; the colloidal AuNPs were, thereafter, drop cast onto a stainless-steel sample plate and the resulting AuNP film was thermally annealed in order to improve its effectiveness as LDI-MS promoter. Spectroscopic characterization of the nanostructured film by X-ray photoelectron spectroscopy was crucial for understanding how annealing induced changes in the surface chemistry and influenced the performance of AuNPs as desorption/ionisation promoter. In particular, it was demonstrated that the post-deposition treatments were essential to enhance the AuNP core/analyte interaction, thus resulting in SALDI-MS spectra of significantly improved quality. The AuNP films were applied to the detection of three different classes of low molecular weight (LMW) analytes, i.e. amino acids, peptides and LMW polymers, in order to demonstrate the versatility of this nanostructured material. © Springer-Verlag 2012.

We will report here on the design and realization of an optoacoustic sensor for the detection of formaldehyde. The sensor consists of a commercial QCL and a resonant PA cell. Two different cell configurations have been investigated: a "standard" H cell and an innovative T-cell with an optical fiber directly inserted into. Two different type of sound detector have been employed: electret microphones and optical MEMS-based microphone. As possible applications, we will describe the results obtained in the detection of formaldehyde (CH(2)O), a gas of great interest for industrial processes and environmental monitoring.

A simple and time-saving wet method to endow the surface of organic semiconductor films with carboxyl functional groups is presented. A thin layer of poly(acrylic acid) (pAA) is spin-coated directly on the electronic channel of an electrolyte-gated organic FET (EGOFET) device and cross-linked by UV exposure without the need for any photo-initiator. The carboxyl functionalities are used to anchor phospholipid bilayers through the reaction with the amino-groups of phosphatidyl-ethanolamine (PE). By loading the membranes with phospholipids carrying specific functionalities, such a platform can be easily implemented with recognition elements. Here the case of biotinylated phospholipids that allow selective streptavidin electronic detection is described. The surface morphology and chemical composition are monitored using SEM and XPS, respectively, during the whole process of bio-functionalization. The electronic and sensing performance level of the EGOFET biosensing platform is also evaluated. Selective analyte (streptavidin) detection in the low pM range is achieved, this being orders of magnitude lower than the performance level obtained by the well assessed surface plasmon resonance assay reaching the nM level, at most.