International Journal of Electrochemistry The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. A Novel Electrochemical Method for Protionamide Determination Based on Its Interaction with Alizarin Red S Thu, 20 Aug 2015 13:25:07 +0000 The interaction of protionamide with alizarin red S (ARS) and its analytical application were carefully investigated in this contribution. The interaction conditions were carefully studied and optimized by cyclic voltammetry. Under the optimum conditions, the cyclic voltammetry curve of ARS showed an oxidation peak with the peak potential of 0.57 V. After the addition of protionamide to the ARS solution, the peak potential was negatively moved, and meanwhile the oxidation peak current decreased apparently to the concentration of protionamide and then a new method for the protionamide determination was established. The linear equation between the decreasing current (Δip) and protionamide concentration was got as Δip (μA) = 0.01514 (mg/L) −0.01553   with the linear range of 10.0~50.0 mg/L, and the detection limit () was got as 8.25 μg/mL. The effects of coexisting substances on the determination were carefully investigated and the protionamide artificial and tablet samples were detected with satisfactory results. Weili Zhang, Xueliang Niu, Hua Zhang, Qingqing Jiang, and Pingping Zhang Copyright © 2015 Weili Zhang et al. All rights reserved. Evaluation of Hydrophilized Graphite Felt for Electrochemical Heavy Metals Detection (Pb2+, Hg2+) Wed, 08 Jul 2015 10:34:14 +0000 Hydrophilized graphite felt has been used, for the first time, for the electrochemical detection of Hg2+ ions both as single metal species and via its simultaneous detection with Pb2+. To do so, square wave voltammetry (SWV) method was developed with alginate modified graphite felt as working electrode. The structure of the graphite felt such as its high porosity and specific surface area coupled with its good electrical conductivity allows achieving large peak currents via the SWV method, suggesting that the alginate coating helps to preconcentrate metals at the carbon surface. The as-described electrode has low cost, it is easy to manipulate, and the electrochemical analysis can be performed by simple immersion of the felt in the metal solution. Laila Bouabdalaoui, Benjamin Le Ouay, Thibaud Coradin, and Christel Laberty-Robert Copyright © 2015 Laila Bouabdalaoui et al. All rights reserved. An Empirical Rate Constant Based Model to Study Capacity Fading in Lithium Ion Batteries Tue, 07 Jul 2015 12:01:13 +0000 A one-dimensional model based on solvent diffusion and kinetics to study the formation of the SEI (solid electrolyte interphase) layer and its impact on the capacity of a lithium ion battery is developed. The model uses the earlier work on silicon oxidation but studies the kinetic limitations of the SEI growth process. The rate constant of the SEI formation reaction at the anode is seen to play a major role in film formation. The kinetics of the reactions for capacity fading for various battery systems are studied and the rate constants are evaluated. The model is used to fit the capacity fade in different battery systems. Srivatsan Ramesh, K. Venkata Ratnam, and Balaji Krishnamurthy Copyright © 2015 Srivatsan Ramesh et al. All rights reserved. Modeling the Lithium Ion/Electrode Battery Interface Using Fick’s Second Law of Diffusion, the Laplace Transform, Charge Transfer Functions, and a [4, 4] Padé Approximant Wed, 17 Jun 2015 13:39:02 +0000 This work investigates a one-dimensional model for the solid-state diffusion in a LiC6/LiMnO2 rechargeable cell. This cell is used in hybrid electric vehicles. In this environment the cell experiences low frequency electrical pulses that degrade the electrodes. The model’s starting point is Fick’s second law of diffusion. The Laplace transform is used to move from time as the independent variable to frequency as the independent variable. To better understand the effect of frequency changes on the cell, a transfer function is constructed. The transfer function is a transcendental function so a Padé approximant is found to better describe the model at the origin. Consider . John H. Summerfield and Charles N. Curtis Copyright © 2015 John H. Summerfield and Charles N. Curtis. All rights reserved. Structural and Electrochemical Analysis of PMMA Based Gel Electrolyte Membranes Sun, 18 Jan 2015 07:40:59 +0000 New gel polymer electrolytes containing poly(vinylidene chloride-co-acrylonitrile) and poly(methyl methacrylate) are prepared by solution casting method. With the addition of 60 wt.% of EC to PVdC-AN/PMMA blend, ionic conductivity value  S cm−1 has been achieved. XRD and FT-IR studies have been conducted to investigate the structure and complexation in the polymer gel electrolytes. The FT-IR spectra show that the functional groups C=O and C≡N play major role in ion conduction. Thermal stability of the prepared membranes is found to be about 180°C. Chithra M. Mathew, K. Kesavan, and S. Rajendran Copyright © 2015 Chithra M. Mathew et al. All rights reserved. Electrocatalytic Oxidation and Determination of Cysteine at Oxovanadium(IV) Salen Coated Electrodes Sun, 28 Dec 2014 07:40:33 +0000 A transition metal complex, oxovanadium(IV) salen (where salen represents N,N′-bis(salicylidene)ethylenediamine) is immobilized on glassy carbon (GC) electrodes and utilized for electrocatalytic oxidation of cysteine. In presence of oxovanadium(IV) salen, increased oxidation current is observed due to the effective oxidation of cysteine by the electrogenerated oxovanadium(V) salen species. The oxidation current linearly varies with the concentration of cysteine from 0.1 to 1.0 mM. The modified electrode has good sensitivity and low limit of detection. These properties make the oxovanadium(IV) salen as an effective electrocatalyst for the determination of cysteine. Piyush Kumar Sonkar, Vellaichamy Ganesan, and Vijay Rao Copyright © 2014 Piyush Kumar Sonkar et al. All rights reserved. Selection of the Best Process Stream to Remove Ca2+ Ion Using Electrodialysis from Sugar Solution Sun, 14 Dec 2014 10:37:09 +0000 Electrodialytic removal of calcium chloride (CaCl2, 25–50 mol·m−3) from 5% sugar solution was executed in batch recirculation mode. Calcium ion removal rate was monitored with (i) applied potential, (ii) feed flow rate, (iii) solution viscosity and conductivity, and (iv) catholyte streams (NaOH or sodium salt of ethylene diamine tetraacetic acid-acetic acid, Na2EDTA-AA). Unsteady state model for ion concentration change was written for the ED cell used. Linearized Nernst-Planck equation instead of Ohm’s law was applied to closely obtain the current density and concentration change theoretically. The model developed could closely predict the experimental observation. Mass transfer coefficients and specific energy densities were estimated for each combination of catholyte stream used. NaOH showed better performance for a short duration over Na2EDTA-acetic acid combination. Jogi Ganesh Dattatreya Tadimeti, Shilpi Jain, Sujay Chattopadhyay, and Prashant Kumar Bhattacharya Copyright © 2014 Jogi Ganesh Dattatreya Tadimeti et al. All rights reserved. Solvent Effects on the Electrochemical Behavior of TAPD-Based Redox-Responsive Probes for Cadmium(II) Tue, 25 Nov 2014 11:12:20 +0000 Two tetralkylated phenylenediamines (TAPD) 1 and 2 have been prepared by reductive alkylation of para-dimethylaminoaniline with furfural or thiophene 2-carboxaldehyde, respectively. Their chelation ability has been evaluated as electrochemical guest-responsive chemosensors for Cd(II) in acetonitrile (ACN), dimethylformamide (DMF), propylene carbonate (PC), and nitromethane (NM). The voltamperometric studies showed that these compounds are able to bind the Cd(II) cation with strong affinities except in DMF. The redox features of the chemosensors changed drastically when they are bounded to Cd(II) to undergo important anodic potential peak shifts comprised between ca. 500 and ca. 900 mV depending on the solvent. The addition of ∼4–10% molar triflic acid (TfOH) was found to be necessary to achieve rapidly the cation chelation which is slow without the acid. The electrochemical investigations suggested the formation of 1 : 2 stoichiometry complexes [Cd(L)2]2+. The results are discussed in terms of solvent effects as a competitive electron donating ligand to the cation. The reaction coupling efficiency (RCE) values were determined and were also found to be solvent-dependent. Rihab Sahli, Janet Bahri, Issa Tapsoba, Khaled Boujlel, and Noureddine Raouafi Copyright © 2014 Rihab Sahli et al. All rights reserved. Action of Chicory Fructooligosaccharides on Biomimetic Membranes Sun, 16 Nov 2014 11:48:27 +0000 Fructooligosaccharides from chicory (FOSC) are functional prebiotic foods recognized to exert several well-being effects in human health and animal production, as decreasing blood lipids, modulating the gut immune system, enhancing mineral bioavailability, and inhibiting microbial growth, among others. Mechanisms of actions directly on cell metabolism and structure are however little known. In this sense this work was targeted to investigate the interaction of FOSC with biomimetic membranes (liposomes and supported bilayer membrane; s-BLM) through cyclic voltammetry, impedance spectroscopy, spectrofluorimetry, and microscopy. FOSC was able to disrupt the membrane structure of liposomes and s-BLM from the onset of molecular pores induced on it. The mechanism of interaction of fructans with biomimetic membranes suggests hydrogen bonding between the polyhydroxylated structure of the oligosaccharides and the negative polar group of L--phosphatidylcholine (PC) present in both liposomes and s-BLM. A. F. Barbosa, R. S. Henrique, A. S. Lucho, V. Paffaro Jr., and J. M. Schneedorf Copyright © 2014 A. F. Barbosa et al. All rights reserved. Effect of Low Cobalt Loading on TiO2 Nanotube Arrays for Water-Splitting Sun, 09 Nov 2014 07:23:41 +0000 This work is intended to define a new possible methodology for the TiO2 doping through the use of an electrochemical deposition of cobalt directly on the titanium nanotubes obtained by a previous galvanostatic anodization treatment in an ethylene glycol solution. This method does not seem to cause any influence on the nanotube structure, showing final products with news and interesting features with respect to the unmodified sample. Together with an unmodified photoconversion efficiency under UV light, the cobalt doped specimen reports an increase of the electrocatalytic efficiency for the oxygen evolution reaction (OER). Alfonso Pozio Copyright © 2014 Alfonso Pozio. All rights reserved. Synthesis and Characterization of Electrodeposited C-PANI-Pd-Ni Composite Electrocatalyst for Methanol Oxidation Thu, 16 Oct 2014 14:42:07 +0000 Electropolymerization of aniline at the graphite electrodes was achieved by potentiodynamic method. Electrodeposition of Pd (C-PANI-Pd) and Ni (C-PANI-Ni) and codeposition of Pd-Ni (C-PANI-Pd-Ni) microparticles into the polyaniline (PANI) film coated graphite (C-PANI) were carried out under galvanostatic control. The morphology and composition of the composite electrodes were obtained using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) techniques. The electrochemical behavior and electrocatalytic activity of the electrode were characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometric (CA) methods in acidic medium. The C-PANI-Pd-Ni electrode showed an improved catalytic performance towards methanol oxidation in terms of lower onset potential, higher anodic oxidation current, greater stability, lower activation energy, and lower charge transfer resistance. The enhanced electrocatalytic activity might be due to the greater permeability of C-PANI films for methanol molecules, better dispersion of Pd-Ni microparticles into the polymer matrixes, and the synergistic effects between the dispersed metal particles and their matrixes. S. S. Mahapatra, S. Shekhar, B. K. Thakur, and H. Priyadarshi Copyright © 2014 S. S. Mahapatra et al. All rights reserved. Role of Indium Alloying with Lead as a Means to Reduce the Passivation Phenomena in Lead/Acid Batteries Tue, 23 Sep 2014 00:00:00 +0000 The influence of indium content on the anodic behaviour of Pb-In alloys in 4 M H2SO4 solution is investigated by potentiodynamic, potentiostatic, chronopotentiometric, and cyclic voltammetric techniques. The composition and microstructure of the corrosion layer on Pb-In alloys are characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy analysis (EDX), and scanning electron microscopy (SEM). The potentiodynamic and chronopotentiometric curves show that the anodic behavior of all investigated electrodes exhibits active/passive transition. The active dissolution (except for alloy I) and passive currents increase with increasing both In content and temperature. This indicates that the conductivity of the anodic film on Pb-In alloy is enhanced. This study exhibits that indium catalyses the oxidation of Pb (II) to Pb (IV) and facilitates the formation of a more highly conductive corrosion layer on lead. Alloy I (0.5% In) exhibits that the corrosion rate is lower, while the passive current is higher than that of Pb. XRD, EDX, and SEM results reveal that the formation of both PbSO4 and PbO on the surface decreases gradually with increasing In level in the alloy and completely disappear at higher In content (15% In). Therefore, recharge of the battery will be improved due to indium addition to Pb. Abdel-Rahman El-Sayed, Hossnia S. Mohran, and Hoda Abdel Shafy Shilkamy Copyright © 2014 Abdel-Rahman El-Sayed et al. All rights reserved. Using Poly-L-Histidine Modified Glassy Carbon Electrode to Trace Hydroquinone in the Sewage Water Mon, 08 Sep 2014 00:00:00 +0000 A sensitive voltammetric method for trace measurements of hydroquinone in the sewage water is described. The poly-L-histidine is prepared to modify the glassy carbon electrode in order to improve the electrochemical catalysis of interesting substances such as hydroquinone. The influence of the base solution, pH value, and scanning speed on the tracing of hydroquinone is discussed, and the experimental procedures and conditions are optimized. The laboratory results show that it is possible to construct a linear calibration curve between the peak current of hydroquinone on modified electrode and its concentration at the level of 0.00001 mol/L. The potential limitation of the method is suggested by a linear peaking shift model as well. The method was successfully applied to the determination of hydroquinone in the actual sample of industrial waste water. Bin Wang and Jun Steed Huang Copyright © 2014 Bin Wang and Jun Steed Huang. All rights reserved. Electron Transfer of Myoglobin Immobilized in Au Electrodes Modified with a RAFT PMMA-Block-PDMAEMA Polymer Sun, 31 Aug 2014 08:24:50 +0000 Myoglobin was immobilized with poly(methyl methacrylate)-block-poly[(2-dimethylamino)ethyl methacrylate]PMMA-block-PDMAEMA polymer synthesized by reversible addition-fragmentation chain transfer technique (RAFT). Cyclic voltammograms gave direct and slow quasireversible heterogeneous electron transfer kinetics between Mb-PMMA-block-PDMAEMA modified electrode and the redox center of the protein. The values for electron rate constant () and transfer coefficient () were ·s−1 and , respectively. The reduction potential determined as a function of temperature (293–328 K) revealed a value of reaction center entropy of of  J·mol−1·K−1 and enthalpy change of  kJ·mol−1, suggesting solvent effects and charge ionization atmosphere involved in the reaction parallel to hydrophobic interactions with the copolymer. The immobilized protein also exhibits an electrocatalytical response to reduction of hydrogen peroxide, with an apparent Km of  μM. The overall results substantiate the design and use of RAFT polymers towards the development of third-generation biosensors. Carla N. Toledo, Fábio H. Florenzano, and José M. Schneedorf Copyright © 2014 Carla N. Toledo et al. All rights reserved. Exploration of Electrochemical Intermediates of the Anticancer Drug Doxorubicin Hydrochloride Using Cyclic Voltammetry and Simulation Studies with an Evaluation for Its Interaction with DNA Sun, 03 Aug 2014 11:46:06 +0000 Electrochemical behavior of the anticancer drug doxorubicin hydrochloride was studied using cyclic voltammetry in aqueous medium using Hepes buffer (pH~7.4). At this pH, doxorubicin hydrochloride undergoes a reversible two-electron reduction with value − mV (versus Ag/AgCl, saturated KCl). Depending on scan rates, processes were either quasireversible (at low scan rates) or near perfect reversible (at high scan rates). This difference in behavior of doxorubicin hydrochloride with scan rate studied over the same potential range speaks of differences in electron transfer processes in doxorubicin hydrochloride. Attempt was made to identify and understand the species involved using simulation. The information obtained was used to study the interaction of doxorubicin hydrochloride with calf thymus DNA. Cathodic peak current gradually decreased as more calf thymus DNA was added. The decrease in cathodic peak current was used to estimate the interaction of the drug with calf thymus DNA. Nonlinear curve fit analysis was applied to evaluate the intrinsic binding constant and site size of interaction that was compared with previous results on doxorubicin hydrochloride-DNA interaction monitored by cyclic voltammetry or spectroscopic techniques. Partha Sarathi Guin and Saurabh Das Copyright © 2014 Partha Sarathi Guin and Saurabh Das. All rights reserved. Synthesis and Electrochemical Performance of LiMnPO4 by Hydrothermal Method Tue, 08 Jul 2014 07:19:54 +0000 LiMnPO4 with olivinestructure which is the promising candidate for high voltage cathode material was synthesized by hydrothermal method. In order to synthesize high purity and well-defined LiMnPO4, several precursors for Li, Mn, and P sources and hydrothermal reaction parameters including temperature and [H2O]/[Mn] value are optimized. By analyzing the structure, Mn valence, morphology, and chemical ratio via XRD, XPS, Raman, SEM, and ICP LiMnPO4 synthesized from manganese acetate tetrahydrate have single phase of LiMnPO4 without impurity and showed charge and discharge reaction caused by Mn2+/Mn3+ redox. Specific capacity of synthesized LiMnPO4 grew up during cycling. Moreover, when hydrothermal temperature was set at 150°C and [H2O]/[Mn] value was set at 15, discharge capacity as high as 70 mAh/g was obtained at rate. Daichi Fujimoto, Yu Lei, Zheng-Hong Huang, Feiyu Kang, and Junichi Kawamura Copyright © 2014 Daichi Fujimoto et al. All rights reserved. Synthesis of Nitrogen Doped Carbon and Its Enhanced Electrochemical Activity towards Ascorbic Acid Electrooxidation Thu, 26 Jun 2014 13:31:17 +0000 Nitrogen doped carbon, synthesized by a novel way of carbonizing polyaniline in an inert atmosphere at a constant temperature of , exhibits several unique features. The carbon: nitrogen ratio is found to increase with the treatment duration up to 120 minutes and a mass reduction of 60 wt% is observed with an interesting observation of the retention of the bulk polymer morphology, surprisingly, even after the carbonization process. The electrochemical activity evaluated with potassium hexacyanoferrate and hexamine ruthenium redox systems at a regular time interval helps to tune the catalytic activity. This type of nitrogen doped carbon prepared from polyaniline base exhibits excellent electrocatalytic activity as illustrated by the oxidation of ascorbic acid in neutral medium. Sankararao Mutyala and Mathiyarasu Jayaraman Copyright © 2014 Sankararao Mutyala and Mathiyarasu Jayaraman. All rights reserved. Pd-Au Electrocatalysts for Hydrogen Evolution Reaction at Neutral pH Mon, 31 Mar 2014 12:12:23 +0000 Pd-Au codeposits with different ratio of both metals were electrodeposited on carbon felt, characterized by scanning electron microscopy, and investigated as electrocatalysts towards hydrogen evolution reaction in neutral phosphate buffer solution. The quantities of the produced hydrogen gas with different electrocatalysts, estimated from data obtained by chronoamperometry, were confirmed by mass spectrometry analysis. The highest hydrogen evolution rate was achieved with the electrocatalysts, produced from electrolyte with equal Pd and Au content. Elitsa Chorbadzhiyska, Mario Mitov, Georgi Hristov, Nina Dimcheva, Lori Nalbandian, Antigoni Evdou, and Yolina Hubenova Copyright © 2014 Elitsa Chorbadzhiyska et al. All rights reserved. Development of Membraneless Sodium Perborate Fuel Cell for Media Flexible Power Generation Thu, 27 Mar 2014 11:52:25 +0000 This paper reports the media flexibility of membraneless sodium perborate fuel cell (MLSPBFC) using acid/alkaline bipolar electrolyte in which the anode is in acidic media while the cathode is in alkaline media, or vice versa. Investigation of the cell operation is conducted by using formic acid as a fuel and sodium perborate as an oxidant for the first time under “acid-alkaline media” configurations. The MLSPBFC architecture enables interchangeable operation with different media combinations. The experimental results indicate that operating under “acid-alkaline media” conditions significantly improves the fuel cell performance compared with all-acidic and all-alkaline conditions. The effects of flow rates and the concentrations of various species at both the anode and cathode on the cell performance are also investigated. It has been demonstrated that the laminar flow based microfluidic membraneless fuel cell can reach a maximum power density of 28.2 mW cm−2 with a fuel mixture flow rate of 0.3 mL min−1 at room temperature. K. Ponmani, S. Durga, A. Arun, S. Kiruthika, and B. Muthukumaran Copyright © 2014 K. Ponmani et al. All rights reserved. Isomers of Poly Aminophenol: Chemical Synthesis, Characterization, and Its Corrosion Protection Aspect on Mild Steel in 1 M HCl Mon, 17 Mar 2014 06:30:28 +0000 The oxidative chemical polymerizations of three isomers of aminophenol, ortho, meta, and para (PoAP, PmAP, and PpAP), were performed in aqueous HCl using ammonium persulfate as an oxidant at 0–3°C. The synthesized polymers were characterized by employing elemental analysis, GPC, UV-VIS-NIR, FT-IR, XRD, and TGA. The corrosion inhibition effect of these three polymers on mild steel in 1 M HCl solution was studied by using electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy. These measurements reveal that the inhibition efficiency obtained by these polymers increased by increasing their concentration. The inhibition efficiency follows the order PpAP > PoAP > PmAP. The results further revealed that PpAP at a concentration of 250 mg/L furnishes maximum inhibition efficiency (96.5%). Polarization studies indicated that these three polymers act as the mixed type corrosion inhibitors. G. Thenmozhi, P. Arockiasamy, and R. Jaya Santhi Copyright © 2014 G. Thenmozhi et al. All rights reserved. Electroanalytical Methodology for the Direct Determination of 2,4-Dichlorophenoxyacetic Acid in Soil Samples Using a Graphite-Polyurethane Electrode Sun, 16 Mar 2014 13:08:57 +0000 An electroanalytical methodology was developed for the direct determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) using a graphite-polyurethane composite electrode and square wave voltammetry (SWV). 2,4-D exhibited one reduction peak with characteristics of an irreversible process at −0.54 V (versus Ag/AgCl), which is controlled by the diffusion of the reagent on the electrode surface. After the experimental parameters optimization (pH 2.0,  s−1,  V, and  V), analytical curves were constructed in the range of 0.66 mg L−1 to 2.62  mg L−1. Detection (LD) and quantification (LQ) limits were 17.6 g L−1 and 58.6 g L−1, respectively. The methodology was successfully applied to measure the percolation of the herbicide 2,4-D in undisturbed soil columns of different granulometric compositions. Fernanda Ramos de Andrade, Renata Alves de Toledo, and Carlos Manoel Pedro Vaz Copyright © 2014 Fernanda Ramos de Andrade et al. All rights reserved. The Corrosion Behaviour of WC-Co-Ru Alloys in Aggressive Chloride Media Thu, 27 Feb 2014 07:34:45 +0000 Hardmetals possess excellent wear resistance, making them suitable alloys in several industrial applications. Mine waters with both dissolved chloride and sulphate salts can be severely corrosive and can limit the application of hardmetal tools in the mining industry. Ru additions to these alloys can refine and improve selected mechanical properties, but its influence on the corrosion resistance is unknown. A series of WC-Co-Ru alloys was evaluated in different chloride containing media to investigate their corrosion resistance. Standard electrochemical corrosion tests, chronoamperometric measurements, and surface analyses with Raman spectroscopy were conducted. An increasing amount of Ru improves the corrosion resistance of all the alloys. The effect is not as dramatic as that observed with stainless steels containing Ru in corrosive media. In both corrosive media Ru decreased the cathodic Tafel constant and has a retarding influence on the cathodic part of the corrosion reaction. Raman analyses indicated the presence of tungsten oxide, hydrated tungsten oxide compounds, and CoO and Co3O4 formed on the alloy surfaces during the corrosion process. J. H. Potgieter, P. Olubambi, and S. S. Potgieter-Vermaak Copyright © 2014 J. H. Potgieter et al. All rights reserved. Power Generation from Human Leukocytes/Lymphocytes in Mammalian Biofuel Cell Mon, 30 Dec 2013 18:34:39 +0000 Alternative to batteries power sources is needed for the human implants of the future that tend to be less invasive and more integrated to human biology and physiology. Human metabolism could be exploited for the generation of power, but mammalian cells protect their energy production apparatus from external electrochemical scavengers. We report here evidence that, in the case of white blood cells, chemical energy can be harvested directly on an electrode as electricity in fuel cells whose stability is roughly parallel to the viability of cells in vitro. Electrochemical activity of human leukocytes immobilized on modified carbon mesh electrodes was investigated by cyclic voltammetry. Oxidation peaks at 0.33 V versus Ag/AgCl were observed. An open-circuit potential of 0.44 V was recorded between anode and cathode compartments where the biofuel cell potential operating under an external load of 5 kΩ was below 0.35 V. Average power outputs of 10 μW ( μW/cell) were increased to 15 μW by the activation of white blood cells. Power densities of 1.5 μW cm−2 for lower than physiological cell concentrations are low for most of today’s implants, but possibility of cell immobilization allows a positive outlook for the future utility of the reported findings. Güray Güven, Pablo Lozano-Sanchez, and Arcan Güven Copyright © 2013 Güray Güven et al. All rights reserved. Electrochemical and Spectroscopic Characterization of Aluminium(III)-para-methyl-meso-tetraphenylporphyrin Complexes Containing Substituted Salicylates as Axial Ligands Mon, 30 Dec 2013 11:44:58 +0000 A series of aluminium(III)-p-methyl-meso-tetraphenylporphyrin (p-CH3TPP-Al(III)) containing axially coordinated salicylate anion [p-CH3TPP-Al-X)], where X = salicylate (SA), 4-chlorosalicylate (4-CSA), 5-chlorosalicylate (5-CSA), 5-flourosalicylate (5-FSA), 4-aminosalicylate (4-ASA), 5-aminosalicylate (5-ASA), 5-nitrosalicylate (5-NSA), and 5-sulfosalicylate (5-SSA), have been synthesized and characterized by various spectroscopic techniques including ultraviolet-visible (UV-vis), infrared (IR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, 13C NMR, and elemental analysis. A detailed study of electrochemistry of all the synthesized compounds has been done to compare their oxidation and reduction mechanisms and to explain the effect of axial coordination on their redox properties. Gauri D. Bajju, Deepmala, Sunil Kumar Anand, Sujata Kundan, and Narinder Singh Copyright © 2013 Gauri D. Bajju et al. All rights reserved. Analytical Expressions for Steady-State Concentrations of Substrate and Oxidized and Reduced Mediator in an Amperometric Biosensor Tue, 24 Dec 2013 13:18:47 +0000 A mathematical model of modified enzyme-membrane electrode for steady-state condition is discussed. This model contains a nonlinear term related to enzyme kinetics reaction mechanism. The thickness dependence of an amperometric biosensor is presented both analytically and numerically where the biological layer is immobilized between a solid substrate and permeable electrode. The analytical expressions pertaining to the concentration of species and normalized current are obtained using the Adomian decomposition method (ADM). Simple and approximate polynomial expressions of concentrations of an oxidized mediator, substrate, and reduced mediator are derived for all possible values of parameters (Thiele modulus), (normalized surface concentration of oxidized mediator), and (normalized surface concentration of substrate). A comparison of the analytical approximation and numerical simulation is also presented. A good agreement between theoretical predictions and numerical results is observed. Loghambal Shunmugham and L. Rajendran Copyright © 2013 Loghambal Shunmugham and L. Rajendran. All rights reserved. Square Wave Voltammetric Determination of 2-Thiouracil in Pharmaceuticals and Real Samples Using Glassy Carbon Electrode Tue, 24 Dec 2013 11:05:44 +0000 A simple and rapid method was developed using cyclic and square wave voltammetric techniques for the determination of trace-level sulfur containing compound, 2-thiouracil, at a glassy carbon electrode. 2-thiouracil produced two anodic peaks at 0.334 V and 1.421 V and a cathodic peak at −0.534 V. The square wave voltammetry of 2-thiouracil gave a good linear response in the range of 1–20 μM with a detection limit of 0.16 μM and quantification limit of 0.53 μM (0.0679 μg/g), which is in good agreement as per IUPAC definition of trace component analysis (100 μg/g). The obtained recoveries range from 98.10% to 102.1%. The proposed method was used successfully for its quantitative determination in pharmaceutical formulations and urine as real samples. Naveen M. Gokavi, Vijay P. Pattar, Atmanand M. Bagoji, and Sharanappa T. Nandibewoor Copyright © 2013 Naveen M. Gokavi et al. All rights reserved. Faster-Than-Real-Time Simulation of Lithium Ion Batteries with Full Spatial and Temporal Resolution Tue, 24 Dec 2013 08:56:55 +0000 A one-dimensional coupled electrochemical-thermal model of a lithium ion battery with full temporal and normal-to-electrode spatial resolution is presented. Only a single pair of electrodes is considered in the model. It is shown that simulation of a lithium ion battery with the inclusion of detailed transport phenomena and electrochemistry is possible with faster-than-real-time compute times. The governing conservation equations of mass, charge, and energy are discretized using the finite volume method and solved using an iterative procedure. The model is first successfully validated against experimental data for both charge and discharge processes in a battery. Finally, it is demonstrated for an arbitrary rapidly changing transient load typical of a hybrid electric vehicle drive cycle. The model is able to predict the cell voltage of a 15-minute drive cycle in less than 12 seconds of compute time on a laptop with a 2.33 GHz Intel Pentium 4 processor. Sandip Mazumder and Jiheng Lu Copyright © 2013 Sandip Mazumder and Jiheng Lu. All rights reserved. Electrochemical Studies of Betti Base and Its Copper(II) Complex by Cyclic and Elimination Voltammetry Sun, 22 Dec 2013 13:59:50 +0000 The electrochemical behavior of Betti base 1-(α-amino benzyl)-2-naphthol (BB) and its copper(II) complex by cyclic and elimination voltammetry (EVLS) is reported in the present study. The cyclic voltammetric studies carried out at a glassy carbon working electrode, Ag/Ag+ reference electrode (0.01 M AgNO3 in acetonitrile) in DCM at 100 mV/sec, 200 mV/sec, and 400 mV/sec scan rates indicated a preceding chemical oxidation of the adsorbed BB species to form an iminium ion followed by formation of a carbanion via two-step quasireversible reduction. The suggested reaction mechanism has been supported by the elimination voltammetry. The CV and EVLS studies revealed Cu(II)BB complex to undergo a chemical or a surface reaction before electron transfer from the electrode at −0.49 V to form Cu(I)BB species. The oxidation of Cu(I)BB species has been observed to be CV silent. Shardul Bhatt and Bhavna Trivedi Copyright © 2013 Shardul Bhatt and Bhavna Trivedi. All rights reserved. Electrochemical Sandwich Immunoassay for the Ultrasensitive Detection of Human MUC1 Cancer Biomarker Sun, 22 Dec 2013 10:22:38 +0000 A new electrochemical sandwich immunoassay for the ultrasensitive detection of human MUC1 cancer biomarker using protein G-functionalized magnetic beads (MBs) and graphite-based screen-printed electrodes (SPEs) was developed. Magnetic beads were employed as the platforms for the immobilization and immunoreaction process. A pair of primary and secondary antibodies was used to capture the MUC1 protein. After labeling with a third antibody conjugated with horseradish peroxidase (HRP), the resulting conjugate was trapped at the surface of the graphite-based SPEs and MUC1 determination was carried out by differential pulse voltammetry (DPV) at 0.4 V upon H2O2 addition using acetaminophen (APAP) as the redox mediator. A linear relationship was obtained for the detection of human MUC1 over a range of 0–25 ppb with the lowest detection limit of 1.34 ppb when HRP was applied as a label. Preliminary experiments were performed using disposable electrochemical sensors in order to optimize some parameters (i.e., incubation times, concentrations, and blocking agent). Zahra Taleat, Cecilia Cristea, Giovanna Marrazza, and Robert Săndulescu Copyright © 2013 Zahra Taleat et al. All rights reserved. Cyclic Voltammetric Investigation of Caffeine at Anthraquinone Modified Carbon Paste Electrode Tue, 17 Dec 2013 14:54:16 +0000 Electrochemical methods have been widely used for the determination of electroactive compounds due to their simplicity, sensitivity, stability, and low cost. A carbon paste electrode was modified with anthraquinone. Cyclic voltammetry (CV) was employed to study the properties of the modified electrode toward the oxidation of caffeine (CAF). Compared to the unmodified electrode, the AQMCPE showed excellent catalytic activity for the oxidation of caffeine. AQMCPE was used to determine CAF in drug samples electrochemically. SWV was used to plot the calibration curve and there was a good linear relationship between anodic peak current and CAF concentration in the range  M, with the correlation coefficient of 0.998 and a detection limit of  M. The application of the modified electrode for the determination of CAF in pharmaceutical formulation showed good recovery with reproducible results. Yemane Tadesse, Abraha Tadese, R. C. Saini, and Rishi Pal Copyright © 2013 Yemane Tadesse et al. All rights reserved.