Dialysis and column chromatography for biomass pyrolysis liquids separation.

In the current study, a novel approach for separating value-added chemicals from pine wood residues' pyrolysis liquids (bio-oil) was effectively carried out. It combined two separation techniques used for the first time in this field: dialysis with water, methanol and acetone, and column chromatography with Amberlite™ XAD7 resin. This strategy made it possible to separate bio-oil into four fractions: (1) pyrolytic lignin, which can be utilized in the synthesis of resins, foams, electrodes, asphalt, etc.

Excitation and detection of acoustic phonons in nanoscale systems.

Phonons play a key role in the physical properties of materials, and have long been a topic of study in physics. While the effects of phonons had historically been considered to be a hindrance, modern research has shown that phonons can be exploited due to their ability to couple to other excitations and consequently affect the thermal, dielectric, and electronic properties of solid state systems, greatly motivating the engineering of phononic structures. Advances in nanofabrication have allowed for structuring and phonon confinement even down to the nanoscale, drastically changing material properties.

Inkjet-Printed Sulfide-Selective Electrode.

Inkjet printing technology has emerged as an alternative manufacturing method for low-cost production of electrodes. Despite significant progress, there is still a lack in the production of ion-selective electrodes. Herein, the two-step fabrication of the first inkjet-printed sulfide-selective electrode (IPSSE) is described.

BioElectronic Tongue for the quantification of total polyphenol content in wine.

This work reports the application of a BioElectronic Tongue (BioET) in the estimation of polyphenol content in wine. The approach used an array of enzyme biosensors capable of giving a wide and complete response of the analyzed species, plus a chemometric processing tool able to interpret the chemical signals and extract meaningful data from the complex readings. In our case, the proposed BioET was formed by an array of four voltammetric enzymatic biosensors based on epoxy-graphite composites, one blank electrode and the other three bulk-modified with tyrosinase and laccase on one side, and copper nanoparticles on the other; these modifiers were used in order to incorporate differentiated or catalytic response to different polyphenols present in wine and aimed to the determination of its total polyphenol content value.

Resolution of phenolic antioxidant mixtures employing a voltammetric bio-electronic tongue.

This work reports the application of a Bio-Electronic Tongue (BioET) system made from an array of enzymatic biosensors in the analysis of polyphenols, focusing on major polyphenols found in wine. For this, the biosensor array was formed by a set of epoxy-graphite biosensors, bulk-modified with different redox enzymes (tyrosinase and laccase) and copper nanoparticles, aimed at the simultaneous determination of the different polyphenols. Departure information was the set of voltammograms generated with the biosensor array, selecting some characteristic features in order to reduce the data for the Artificial Neural Network (ANN).

A new amperometric bienzymatic biosensor based on biocomposites for the determination of gluconic acid in wines.

A new amperometric bienzymatic biosensor for gluconic acid based on the coimmobilization of gluconokinase (EC 2.7.1.

Highly sensitive CNT composite amperometric sensors integrated in an automated flow system for the determination of free chlorine in waters.

We report the benefit of using an optimized composite electrode, based on a multiwall carbon nanotubes and epoxy resin, as working electrode in an automated flow system. The optimal composite electrode composition consists in a 10% carbon nanotubes and 90% epoxy resin. This composition provides lower limit of detection and increases the stability and reproducibility of the analytical signal compared to the 20% conventional composition electrodes.

Flow injection analysis system based on amperometric thin-film transducers for free chlorine detection in swimming pool waters.

This work reports on the performance of a user-friendly flow injection analysis (FIA) system for the monitoring of free chlorine. A methacrylate flow cell integrating a gold thin-film microelectrode, together with an on-chip gold counter electrode, both fabricated by microfabrication technology, provided robustness, low output impedance, rapid response and low cost to the proposed flow system. An external Ag/AgCl reference electrode placed downstream the chip completes the electrochemical cell.

Wavelet neural networks to resolve the overlapping signal in the voltammetric determination of phenolic compounds.

Three phenolic compounds, i.e. phenol, catechol and 4-acetamidophenol, were simultaneously determined by voltammetric detection of its oxidation reaction at the surface of an epoxy-graphite transducer.

Composite planar electrode for sensing electrochemical oxygen demand.

This work reports on the development of a graphite-polystyrene composite electrode of planar configuration, containing silver(II) oxide and copper(II) oxide catalysts (AgO-CuO), for the measurement of electrochemical oxygen demand (EOD). Optimisation studies of the composite composition as well as conditions for its processing on planar substrates and generation of an appropriate electrochemical active area resulted in the scalable fabrication of robust composite electrodes. These were evaluated with glucose as target analyte.

Carbon composite microelectrodes: charge percolation and electroanalytical performance.

Microelectrodes based on two different epoxy-graphite composites (Araldite-M/HY5162 and Araldite-PY302-2/HY943) that are compatible with organic solvents have been developed and characterized. The variation in the bulk conductivity with graphite particle loading is described by percolation theory and indicates that the particles interact strongly with one another. The percolation threshold is 52% v/v loading of graphite, and this composite exhibits a bulk conductivity of 15 S m(-1).

Carbon composite electrodes: surface and electrochemical properties.

Electrodes based on particulate carbon-epoxy or silicone composites have been formed and characterised using electrochemical methods, scanning electron microscopy and scanning electrochemical microscopy. These composites are rigid, exhibit high electrical conductivity and are stable in organic solvents for prolonged periods. The bulk resistance of the Araldite-M and Araldite-CW2215 based electrodes is low, 130+/-12 and 185+/-15 ohms, respectively.