Functionalized conjugating polymers: from molecule and ions transporting membranes to advanced electronic and photonic materials

A b s t r u Applications of conjugating polymers to advanced materials are demonstrated, especially focusing on artificial membrane, electronic and photonic advanced materials, such as (1) selective and transporting membrane, (2) functional molecular materials and devices including charge controllable membranes, (3) ultrahigh anisotropic conducting polymer material, (4) conjugating polymer superlattice and ( 5 ) one-dimensional (1-D) and two-dimensional (2-D) porphyrin arrays connected with conjugating and/or insulating molecular wires

Characterization of Low Temperature Soluble Polyaniline

Because the charging of polyaniline films occurs in the bulk of the material rather than exclusively at the polymer-electrolyte interface, the use of thick polymer films for battery applications is justifiable. Here, we present a method for producing soluble polyaniline which can be cast to form free-standing films. Investigation by scanning electron microsopy (SEM) has shown that these films are significantly more compact than those made by standard electropolymerization

Wavefront compensation method using novel index in holographic data storage

Photopolymer media that uses holographic data storage generally causes volume shrinkage. This volume shrinkage distorts the recorded interference fringes. We propose an adaptive optics using novel index to compensate this distortion. The SNR value is improved from 2.1 dB to 3.4 dB in the worst part of a reproduced image and the peak intensity and the full width of the half maximum of an angle are improved by 6% and 10%, respectively. These results prove that adaptive optics using this novel index worked effectively

One-year stability of glucose dehydrogenase confined in a 3D carbon nanotube electrode with coated poly-methylene green: Application as bioanode for a glucose biofuel cell

International audienceWe report a new approach to fabricate an efficient 3D glucose bioanode based on the co-immobilization of the enzyme glucose dehydrogenase (GDH), its cofactor NADP, and Multiwall Carbon Nanotubes (MWCNTs) coated with poly (methylene green) (PMG). The MWCNT-PMG composite was obtained by chemical polymerization of methylene green (MG) monomer on the MWCNT surfaces. Structural and chemical analyses clearly showed successful coating of the MWCNTs with PMG that markedly affected their morphological and surface charge properties. Electrochemical investigation of PMG-MWCNTs mixed with GDH and NADP showed high stability with extended bioanode electrocatalytic activity toward glucose oxidation for more than one year

Preparation of a Polypyrrole-Polyvinylsulphonate Composite Film Biosensor for Determination of Cholesterol Based on Entrapment of Cholesterol Oxidase

In this paper, a novel amperometric cholesterol biosensor with immobilization of cholesterol oxidase on electrochemically polymerized polypyrrole–polyvinylsulphonate (PPy–PVS) films has been accomplished via the entrapment technique on the surface of a platinum electrode. Electropolymerization of pyrrole and polyvinylsulphonate on the Pt surface was carried out by cyclic voltammetry between −1.0 and +2.0 V (vs. Ag/AgCl) at a scan rate of 100 mV upon the Pt electrode with an electrochemical cell containing pyrrole and polyvinylsulphonate. The amperometric determination is based on the electrochemical detection of H2O2 generated in the enzymatic reaction of cholesterol. Determination of cholesterol was carried out by the oxidation of enzymatically produced H2O2 at 0.4 V vs. Ag/AgCl. The effects of pH and temperature were investigated and optimum parameters were found to be 7.25 and 35 °C, respectively. The storage stability and operational stability of the enzyme electrode were also studied. The results show that 32% of the response current was retained after 19 activity assays. The prepared cholesterol biosensor retained 43% of initial activity after 45 days when stored in 0.1 M phosphate buffer solution at 4 °C

Astaxanthin in Exercise Metabolism, Performance and Recovery: A Review

During periods of heavy exercise training and competition, lipid, protein and nucleic molecules can become damaged due to an overproduction of reactive oxygen and nitrogen species within the exercising organism. As antioxidants can prevent and delay cellular oxidative damage through removing, deactivating and preventing the formation of reactive oxygen and nitrogen species, supplementation with exogenous antioxidant compounds has become a commercialised nutritional strategy commonly adopted by recreationally active individuals and athletes. The following review is written as a critical appraisal of the current literature surrounding astaxanthin and its potential application as a dietary supplement in exercising humans. Astaxanthin is a lipid-soluble antioxidant carotenoid available to supplement through the intake of Haematococcus pluvialis-derived antioxidant products. Based upon in vitro and in vivo research conducted in mice exercise models, evidence would suggest that astaxanthin supplementation could potentially improve indices of exercise metabolism, performance and recovery because of its potent antioxidant capacity. In exercising humans, however, these observations have yet to be consistently realised, with equivocal data reported. Implicated, in part, by the scarcity of well-controlled, scientifically rigorous research, future investigation is necessary to enable a more robust conclusion in regard to the efficacy of astaxanthin supplementation and its potential role in substrate utilisation, endurance performance and acute recovery in exercising humans

Doped Overoxidized Polypyrrole Microelectrodes as Sensors for the Detection of Dopamine Released from Cell Populations

A surface modification of interdigitated gold microelectrodes (IDEs) with a doped polypyrrole (PPy) film for detection of dopamine released from populations of differentiated PC12 cells is presented. A thin PPy layer was potentiostatically electropolymerized from an aqueous pyrrole solution onto electrode surfaces. The conducting polymer film was doped during electropolymerization by introducing counter-ions in the monomer solution. Several counter-ions were tested and the resulting electrode modifications were characterized electrochemically to find the optimal dopant that increases sensitivity in dopamine detection. Overoxidation of the PPy films was shown to contribute to a significant enhancement in sensitivity to dopamine. The changes caused by overoxidation in the electrochemical behavior and electrode morphology were investigated using cyclic voltammetry and SEM as well as AFM, respectively. The optimal dopant for dopamine detection was found to be polystyrene sulfonate anion (PSS-). Rat pheochromocytoma (PC12) cells, a suitable model to study exocytotic dopamine release, were differentiated on IDEs functionalized with an overoxidized PSS--doped PPy film. The modified electrodes were used to amperometrically detect dopamine released by populations of cells upon triggering cellular exocytosis with an elevated K+ concentration. A comparison between the generated current on bare gold electrodes and gold electrodes modified with overoxidized doped PPy illustrates the clear advantage of the modification, yielding 2.6-fold signal amplification. The results also illustrate how to use cell population based dopamine exocytosis measurements to obtain biologically significant information that can be relevant in, for instance, the study of neural stem cell differentiation into dopaminergic neurons