02379nas a2200265   4500008004100000022001400041245008500055210006900140260009500209300001000304490000800314520144900322653002001771653002301791653001501814653001401829653001101843653001901854100002501873700003001898700002201928700002101950700002601971856011601997       2007                        eng d  a0006-291X00aAll-solid-state' electrochemistry of a protein-confined polymer electrolyte film0 aAllsolidstate electrochemistry of a proteinconfined polymer elec  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcDEC  a86-910 v3643 a<p>Interfacial redox behavior of a heme protein (hemoglobin) confined in a solid polymer electrolyte membrane, Nafion (a perfluoro sulfonic acid ionomer) is investigated using a unique `all-solid-state' electrochemical methodology. The supple phase-separated structure of the polymer electrolyte membrane, with hydrophilic pools containing solvated protons and water molecules, is found to preserve the incorporated protein in its active form even in the solid-state, using UV-visible, Fluorescence (of Tryptophan and Tyrosine residues) and DRIFT (diffuse reflectance infrared Fourier transform) spectroscopy. More specifically, solid-state cyclic voltammetry and electrochemical impedance of the protein-incorporated polymer films reveal that the Fe2+-form of the entrapped protein is found to bind molecular oxygen more strongly than the native protein. In the `all-solid-state' methodology, as there is no need to dip the protein-modified electrode in a liquid electrolyte (like the conventional electrochemical methods), it offers an easier means to study a number of proteins in a variety of polymer matrices (even biomimetic assemblies). In addition, the results of the present investigation could find interesting application in a variety of research disciplines, in addition to its fundamental scientific interest, including protein biotechnology, pharmaceutical and biomimetic chemistry. (C) 2007 Elsevier Inc. All rights reserved.</p>10aall-solid-state10acyclic voltammetry10ahemoglobin10aImpedance10aNafion10aredox behavior1 aParthasarathy, Meera1 aPillai, Vijayamohanan, K.1 aMulla, Imtiaz, S.1 aShabab, Mohammed1 aKhan, Mohammad, Islam  uhttps://library.ncl.res.in/content/all-solid-state-electrochemistry-protein-confined-polymer-electrolyte-film-002367nas a2200217   4500008004100000022001400041245015500055210006900210260010200279300001200381490000800393520150000401653002301901653001201924653001101936653001301947653000901960100002501969700003001994856012502024       2009                        eng d  a0253-413400aImaging hydrogen oxidation activity of catalyst-coated perfluoro sulfonic acid-polymer electrolyte membranes using scanning electrochemical microscopy0 aImaging hydrogen oxidation activity of catalystcoated perfluoro   aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbINDIAN ACAD SCIENCEScSEP  a719-7250 v1213 a<p>Scanning Electrochemical Microscopy (SECM) is a unique technique for studying fast heterogeneous kinetics and to map reactivity gradients along the surface of an electrocatalyst, especially when it involves multiple surface sites of varying reactivity. It combines the dual advantages offered by ultramicroelectrode (UME) voltammetry in terms of reduced ohmic drop and insignificant double layer charging contribution with the advantages of imaging by rastering the UME across an electro-active surface. In this work, we demonstrate these distinctive features of SECM in evaluating reactivity gradients on catalyst (Pt/C) coated NafionA (R) films towards hydrogen oxidation activity, a reaction of immense technological relevance. Imaging has been performed in the feedback mode by allowing H(2) evolution at the tip (25 A mu m Pt UME), which is reoxidized at the substrate electrode containing Pt/C-Nafion film. Interesting distribution in H(2) oxidation activity has been observed as a function of potential applied to the Pt/C-Nafion film. In addition, a plot of normalized tip current versus the substrate electrode potential indicates the effect of potential-induced reactivity change in the catalyst-coated membranes. The results of the present investigation are believed to be useful to H(2)/O(2) PEM fuel cells with respect to evaluating reactivity gradients of catalyst-coated polymer electrolyte membranes, which is important to rectify problems related to catalyst utilization.</p>10ahydrogen oxidation10aImaging10aNafion10aplatinum10aSECM1 aParthasarathy, Meera1 aPillai, Vijayamohanan, K.  uhttps://library.ncl.res.in/content/imaging-hydrogen-oxidation-activity-catalyst-coated-perfluoro-sulfonic-acid-polymer-0