bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymers Based on Sulfonated Polyanillines for Direct Electron Transfer with (PQQ)GDH and Application in Carbon Nanostructure-Based Biofuel Cells
Authors: Lisdat Fred , Sarauli David , Scherbahn Vitali , Göbel Gero , Putze Marie , Heinlein Thorsten , Schneider Jörg J. 
Published: February 2020

Dopant-functionalized anilines with improved electrocatalytic properties are promising building blocks for the construction of bioelectronic devices [1]. The present study is devoted to the use of polyanillines possessing different substitution patterns in the interaction with the enzyme PQQ-GDH (pyrroloquinoline quinone dependent glucose dehydrogenase). The aim is to obtain an electron transfer from the substrate reduced enzyme to the polymer without additional shuttle molecules. This has been first studied in solution and then transferred to a surface in order to build a reagentless enzyme electrode.
6 polymers have been prepared from different mixtures of sulfoxy-, methoxy- and carboxy-substituted aniline by chemical synthesis and characterized by UV/VIS, IR and NMR spectroscopy. The substitution pattern influences the reactivity of the different polymers with the enzyme in solution, however when fixed on electrode surfaces the potential can be effectively used to enforce the reaction [2].
One of the polymers (poly(3-aminobenzoic acid-co-2-methoxyaniline-5-sulfonic acid) has been applied in modifying carbon nanotube based electrode structures and coupling (PQQ)GDH for construction of a bioanode. The first fuel cell uses MWCNT-based bucky paper as electrode material. The PQQ-GDH has been covalently coupled to the polymer. The glucose oxidation of this electrode achieves a current density of 700μA/cm2. As cathode PQQ modified bucky paper with covalently bound BOD (bilirubin oxidase) is applied. For this electrode a start potential of about 0.5V vs. Ag/AgCl and a maximum current density of 1mA/cm2 can be observed. The biofuel cell resulting from the bucky paper electrodes shows current densities up to about 100μW/cm2 in a 10mM glucose solution.
In a second approach vertically aligned carbon nanotubes (vaCNT) have been used for the electrode construction. Both enzymes have been immobilized in a similar way as compared to bucky paper. The vaCNT-based fuel cell achieves a maximum power density of 125µW/cm2. Even after three days and several runs of load a power density of more than 110µW/cm2 is retained (quiescent solution, 10mM glucose, room temperature). Furthermore it can be shown that this biofuel cell operates in human serum samples.

[1] Wallace GG, Kane-Maguire LAP. Manipulating and monitoring biomolecular interactions with conducting electroactive polymers. Adv Mater 511 2002;14:953–60.

[2] Sarauli D et al. Differently substituted sulfonated polyanilines: The role of polymer compositions in electron transfer with pyrroloquinoline quinone-dependent glucose dehydrogenase Acta Biomater 2013; 9: 8290-8298
Silica By Chemical Vapor Deposition (CVD): Towards Functional and Durable Bio-Interfaces
Authors: Gupta Gautam 
Published: February 2020

It has clearly been demonstrated over the years that electricity can be derived from fuel cells that employ biological species such as enzyme, organelle or cells as the catalytic element. These fuel cells offer several advantages including high specificity, bio-friendly, ease of synthesis, and more over do not employ precious metal catalyst. Although bio based fuel cells possess these numerous advantages, however they are marred with issues such as lack of long-term stability, poor transport characteristics, and partial oxidation of most fuels resulting in overall low output of electrons. The design of fuel cells today is governed by obtaining parameters including minimal over potential, high current density, minimum transport losses and most importantly long-term stability. In order to achieve the desired properties we need to (a) control electron transport (mediated or direct) (b) effective immobilization technique for enzyme stabilization (3) high surface area and porous electrodes for high energy density and optimum fuel transport.
In this talk, I will go over the promising new sol-gel based techniques to encapsulate biological entities that range from a few nm (enzymes, lipid bilayers) up to micron-sized species (cells and organelles) We have developed two novel techniques that are compatible and have been integrated with fuel cell technologies. The two approaches mainly are (a) CVD approach: chemical vapor deposition of inorganic silica precursors onto the electrodes that contain biological species (b) microwave approach: a rapid biocompatible approach that results in bulk-immobilization of biomolecules in solution and substrates. These process allows precise temporal and spatial control of silica polymerization kinetics through the control of precursor delivery at room temperature and does not require or produce high concentrations of injurious chemicals that can compromise the function of biomolecular assemblies therefore result in optimum immobilization of desired species.
Secondly, I will talk about recent development in our lab of use of paper-based fuel cell that can power real devices including clock and LED. I will discuss the compatibility of immobilization techniques with paper based fuel cells and microbial fuel cells.
Fundamental Studies of Interfacial Phenomena at LiNi0.5Mn1.5O4/Graphite Electrodes in Organic Carbonate Electrolytes
Authors: Jarry Angelique , Lux Simon Franz , Kostecki Robert 
Published: February 2020

The LiNi0.5Mn1.5O4 spinel exhibits a charge capacity of 148 mAh/g and operates at potential ca. 4.7 V vs. Li+/Li i.e., at the edge of the electrochemical stability window of standard carbonate-based electrolytes [1,2]. These conditions can result in electrolyte decomposition, electrode surface film formation, which can lead to impedance rise and overall degradation of the battery cell.
A variety of spectroscopy and microscopy techniques have been used to investigate basic properties of LiNi0.5Mn1.5O4 and its interfacial behavior in Li-ion cells. In fact, a thin surface layer of electrolyte decomposition products has been detected on LiNi0.5Mn1.5O4 composite electrodes by FTIR, XPS, and TEM [3-6].
Interestingly, Raman signal from the electrode/electrolyte interface of cycled cathodes is often obscured by a strong fluorescent signal from the fluorescent products of electrolyte decomposition reactions. It has been also observed in LiNi0.8Co0.15Al0.05O2/graphite Li-ion cells after aging at 55 °C [7]. These fluorescent species, which originate from electrolyte side-reactions tend to spread out through the cell and interfere with the cell chemistry
Interfacial reactions at a LiNi0.5Mn1.5O4 spinel electrode in LiPF6-based organic carbonate-based electrolyte were investigated using FTIR, Raman and fluorescence spectroscopies. In situ fluorescence spectroscopy measurements at a carbon- and binder-free LiNi0.5Mn1.5O4 electrode showed formation of fluorescent species that coincides with the oxidation of Ni2+ in LiNi0.5Mn1.5O4. The majority of these electrolyte oxidation products tend to diffuse away into the electrolyte but some remain at the surface of the electrode and form an unstable layer. The formation of photoluminescent active species is not only influenced by the electrode material and the electrolyte but also by the crystalline orientation of the particle surface. The mechanism of these side reactions and their impact on the interfacial chemistry and electrochemical behavior of the graphite electrode will be discussed.

Acknowledgments

This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies of the U.S. Department of Energy, under contract no. DE-AC02-05CH11231.

References

[1] J.B. Goodenough, Y. Kim, Chemistry of Materials, 22 (2010) 587-603.
[2] R. Santhanam, B. Rambabu, Journal of Power Sources, 195 (2010) 5442-5451.
[3] D. Aurbach, B. Markovsky, Y. Talyossef, G. Salitra, H.J. Kim, S. Choi, Journal of Power Sources, 162 (2006) 780-789.
[4] K.J. Carroll, M.-C. Yang, G.M. Veith, N.J. Dudney, Y.S. Meng, Electrochemical and Solid-State Letters, 15 (2012) A72-A75.
[5] N.M. Hagh, F. Cosandey, S. Rangan, R. Bartynski, G.G. Amatucci, Journal of the Electrochemical Society, 157 (2010) A305-A319.
[6] M. Matsui, K. Dokko, K. Kanamura, J. Electrochem. Soc., 157 (2010) A121-A129.
[7] R. Kostecki, L. Norin, X. Song, F. McLarnon, J. Electrochem. Soc., 151 (2004) A522-A526.
Spectroelectrochemical Behaviour of p-Aminobenzenethiol (p-ABT) on Platinum Group Metals
Authors: Vidal-Iglesias Francisco José , Solla-Gullón José , Pérez Juan Manuel , Feliu Juan 
Published: February 2020

Researchers have particular interest in amino-terminated monolayers because they have been used for several applications. Among them, SAMs based on aromatic thiols have been vastly studied. The formation of organic monolayers by self-assembly is directed by a specific interaction between a terminal functional group and the surface, in this case the bond formed between the thiol sulphur and the metal. Aminobenzenethiols (ABTs) are frequently studied as SERS probe molecules and particularly the p-ABT is commonly used as molecular junction and building block in SAMs. Several contributions have been reported about the p-ABT adsorbed on Ag and Au due to the same specific behaviour under certain experimental circumstances. SERS from the self-assembled monolayer of p-ABT on Ag and Au is significantly different from the normal Raman spectrum of the molecule in solid state. In a normal Raman spectrum only bands that correspond to completely symmetric a1 vibrations are observed, but in its SERS spectrum, non-a1-type bands are also present (1143, 1390 and 1432 cm-1). However, the SERS from benzenethiol on these metals are substantially the same as the normal Raman spectrum. It was first speculated [1, 2] that the alteration of the spectrum of p-ABT could be due to the CT mechanism contribution, as a consequence of the alteration of the electronic states of benzenethiol by the introduction of an -NH2 group on the benzene ring. Alternatively, it was shown, based on the spectral similarity of p-ABT and 4,4’-DMAB, that the non-a1-type bands correspond to N=N stretching vibrations of 4,4’-DMAB produced from p-ABT via a catalytic coupling reaction [3]. Recently, the formation of the azo-derivative, observed in the cases of gold and silver surfaces, was not detected on copper surfaces [4] pointing out that the metal could play an important role in the azobenzene derivative formation. In our knowledge no studies have been done with Pt-group metals, which are generally accepted to be weak electromagnetic enhancing metals under conditions of visible wavelength excitation. Consequently, the CT mechanism could play an important role. We report in this work a spectroelectrochemical study with different Pt-group metals, for which a correlation between their voltammetric behaviour and the SERS spectra is established.
Figure. (A) SERS spectra and (B) Cyclic voltammetry of p-ABT on Pt nanoparticles depostited on glassy carbon. Test solution: 0.1 M NaClO4 + 0.001 M p-ABT. Sweep rate: 50 mVs-1

[1] Osawa, M., Matsuda, N., Yoshii, K., Uchida, I., J. Phys. Chem. 98 (1994) 12702
[2] Kim, K., Kim, K.L., Shin, K.S., J. Phys. Chem. C 117 (2013) 5975
[3]Huang, Y.F. Zhu, H.P., Liu, G.K., Wu, D.Y., Ren, B. Tian, Z.Q. J. Am. Chem. Soc. 132 (2010) 9244
[4] Dendisova, M., Havranek, L., Oncak, M. Matejka, P. J. Phys. Chem. C 117 (2013) 21245
Potentiometry in Gas Phase
Authors: Janata Jiri 
Published: February 2020

Properties of organic semiconductors (OS) are controlled by the primary and secondary doping1,2. These highly versatile materials have found sensing application in modern potentiometric sensors for ions as well as for potentiometric sensing of gases. Operation of the equilibrium ion sensors is governed by the modulation of the potential at the interface between the solution and the OS, according to the Nikolskij-Eisenman equation. Exchange of ions with the OS can be seen as a form of primary doping of the latter. For the operation of such potentiometric sensors a stable and well-defined external reference electrode is needed2.
When a dry, solid state OS is exposed to a gas or a vapor that can donate or accept electrons, a charge transfer complex is formed between the OS and the gas. Such interaction is called secondary doping, which results in modulation of work function (WF) of the OS. Such interaction can be measured with a Kelvin Probe or with a field-effect transistor. From the sensing point of view the biggest difference and advantage of WF-FET vis-à-vis ion sensors is the fact that no external reference electrode is needed because silicon is used as reference and its WF is stable under normal operating conditions. That fact alone makes the WF-FETs ideally suited for miniaturization, leading to gas-sensing arrays3.

Jiri Janata and Mira Josowicz, J.Solid State Electrochem. 13 (2009) 41-49, “Organic Semiconductors in Potentiometric Gas Sensors”

Jiri Janata, Principles of Chemical Sensors, 2nd Edition, Springer, 2009, New York

Jiri Janata, Coll.Czechoslov..Chem.Commun.  2009, 74, 1623–1634, Potentiometry in gas phase
Selectivity and Electrochemistry of Symmetrical Ion Channels: A Three-Dimensional Nernst-Planck- Poisson Model Preferred Oral Presentation
Authors: Tkacz-Smiech Katarzyna , Bozek Boguslaw , Lewenstam Andrzej Lewenstam , Danielewski Marek 
Published: February 2020

Ion channels are of major interest for their important function in living organisms. It has been demonstrated that nanofabricated channels can mimictransport properties of biological ones [1].The fluctuations and rectification effects in conical nano-channels are of interest [2]. Although modeling of ionic transport throughout open channel, known as “selective filter”, presents a difficult task it is of major importance in the understanding of fundamental processes in the cell physiology. The so called voltage-gated ion channels have charged domains that make their structure and behavior sensitive to the variation of the applied field. The ion gating is driven by conformal protein changes, that are due to the variation of the electric field. For a particular range of membrane potentials the proteins adopt a conformation with a central narrow hole permeable for chosen ions. Such open channel pores, known as “selective filters”, present a difficult task of major importance in the understanding of fundamental processes in the cell physiology.
Here, the stationary behavior is studied of the different symmetrical channels showing complex geometry. The rigid channel wall is assumed to be locally charged. The ion transport is described by the nonequilibrium steady-state solution in cylindrical geometry of the 3DNernst-Planck-Poisson system. The total flux includes drift (convection) and diffusion terms. The solution of the coupled differential drift-diffusion equations is achieved by finite element method. The essential importance of the asymmetry in the potential distribution at the channel ends on the selectivity effect is demonstrated. The model satisfactorily describes the regime of small-to-moderate ionic currents. For various boundary conditions that are key parameters controlling the selectivity of the channel, it allows determining the flow characteristic, calculating the local concentration across the channel showing cylindrical symmetry and potential distribution. The model gives understanding of the mechanism of ion selectivity by channels but it can be also applied to simulate transport in polymer membranes and nanopores which might be useful in designing biosensors and nanodevices.
[1] Z. Siwy, Y. Gu, H. A. Spohr, D. Baur, A. Wolf-Reber, R. Spohr, P. Apel and Y. E. Korchev, Europhys. Lett. 60 (2002) 349.
[2] I. D. Kosiñska, I. Goychuk, M. Kostur, and G. Schmid, Phys. Rev. E 77 (2008) 031131.
Salt Bridges Contained in Nanoporous Glasses or Polymers: Improved Alternatives to Vycor
Authors: Mousavi Maral P. S. , Buhlmann Philippe 
Published: February 2020

Nanoporous glass plugs are widely used to contain the electrolyte solution that forms a salt bridge between the sample and the reference electrode. Even though reference electrodes with plugs made of nanoporous glass (such as Vycor or CoralPor glass) are commercially available and are frequently used, the limits of their use were not explored until very recently [1]. It will be shown in this presentation that at ionic strengths lower than 100 mM, the half-cell potentials of reference electrodes with nanoporous glass plugs are not sample independent, as it would be desirable, but they depend on the ionic sample composition. Sample dependent shifts of more than 50 mV in the half cell potential were encountered. Reference potentials were found to be affected in aqueous solutions by HCl, NaCl, KCl, and CaCl2, and in acetonitrile by trifluoroacetic acid and the supporting electrolyte tetrabutylammonium perchlorate. These observations cannot be explained by the liquid junction potential between two mutually miscible electrolyte solutions, as commonly described with the Henderson equation. Instead, they result from the surface charge density on the glass surface and the resulting electrostatic screening of ion transfer into the glass pores when the latter have dimensions comparable to or smaller than the Debye length. Users of reference electrodes with nanoporous plugs at the junction to the sample need to be aware of these limitations to avoid substantial measurement errors.
This presentation will also address how problems at the junction to nanoporous plugs can be avoided using novel plug materials and selecting electrolyte conditions judiciously.

References:

[1] Reference Electrodes with Salt Bridges Contained in Nanoporous Glass: An Underappreciated Source of Error, Mousavi, M. P. S.; Bühlmann, P., Anal. Chem.
2013,
85, 8895–8901.
Mechanism of Potential Development for Potentiometric Sensors, Based on Modeling of Interaction Between Electrochemically Active Compounds from the Membrane and Analyte
Authors: Stefan-van Staden Raluca Ioana 
Published: February 2020

Modeling of interaction between analyte and electrochemically active compounds represents a new theoretical approach to predict the response and mechanism of potential development for ion-selective membrane electrodes. Therefore, correlations between the parameters (e.g., free energy, HUMO, LUMO, bound lenght) obtained using modeling, and experimental results (e.g., slope, free energy) obtained using ion-selective electrodes will be shown for sensors based on fullerens. The influence of matrix of the ion-selective electrodes on their response and selectivity will be shown.
The very first results of this study (a new mechanism of potential development for ion-selective electrodes) were discussed with Professor Buck during his participation to a conference in Constantza, Romania in 1993. He was the first that recognized the value of this theoretical spects, and his comments were extremely valuable for the work I developed until now in the theoretical field of ion-selective membrane electrodes.
Acknowledgements This work was supported by UEFISCDI PNII Program Ideas 2011-2014, Contract nr. 123/05.10.2011.
Oxygen Reduction and Oxygen Evolution Reactions in Non-Aqueous Electrolyte As Studies By Dems
Authors: Baltruschat Helmut , Abd-El-Latif Abd-El-Aziz Abd-El-Salehin , Molls Christoph , Khodayari Mehdi , Hegemann Philipp , Bondü Christoph 
Published: February 2020

Secondary lithium-air batteries are promising candidates for a future energy storage system as they provide in theory high capacity; however, in practice they show bad cyclebility. The key step in discharging these batteries is the reduction of oxygen present in air. So far the oxygen reduction reaction (ORR) has been investigated thoroughly in aqueous media, but little research has been done in non-aqueous solvents.
Organic carbonates are unsuitable for the use in lithium-air batteries because they decompose upon charging [1]. Recently Scrosati [2] showed by XRD that tetraethylene glycol dimethyl ether (tetraglyme) is an appropriate electrolyte for Li-air battery whereas Bruce [3] using XRD and FTIR techniques demonstrated that, tetraglyme is not the best electrolyte because it decomposes in the first few cycles. On the other hand, Li2O2 has been reported as the major discharge product using dimethyl sulfoxide (DMSO) as an electrolyte [4].
Since spectroscopic techniques are superior to diffraction methods in detecting charge/discharge products, mass spectrometry in combination with electrochemistry (DEMS) has been used in this study to determine the electrolyte stability, water content, the amount of O2 reduced and evolved in a variety of aprotic electrolytes such as ethers (tetraglyme) and sulfoxide (DMSO). O2 solubility in aqueous and different non-aqueous electrolyte and its dependence on the flow rate of the electrolyte has been studied.
Crucial is a knowledge of the O2 solubility in these electrolytes. We will present a new method for its determination using differential electrochemical mass spectrometry (DEMS) based on the convection and diffusion behaviour characteristices of the dual thin layer cell used for DEMS. [5]
References:
[1] F. Mizuno, et al., Electrochemitry, 2010, 78, 403. [2] H Jung et al., Nat. Chem., 2012, 4, 579. [3] S. Freunberger, et al., Angew. Chem. Int. Ed., 2011, 50, 8609. [4] Z. Peng, et al., Science, 2012, 337, 563. [5] Fuhrmann, J.; Linke, A.; Langmach, H.; Baltruschat, H., Numerical calculation of the limiting current for a cylindrical thin layer flow cell Electrochimica Acta 2009, 55, 430-438.
Electrochemical Properties of Boron-Doped Diamond Thin Film Synthesized by MPCVD on Titanium Substrate to Use as an Ozone Generator
Authors: Park YeongMin , Kim DaeWook , Kim JeongWan , Cho Hyoung J. , Cho Hyun , Kim JinKon , Kim TaeGyu 
Published: February 2020

Boron doped diamond is an excellent electrode material with a large potential window in aqueous solution and low background current. The wider potential window and lower background currents make the BDD material very attractive for electrochemical analysis experiments.
Furthermore, BDD exhibits high chemical and electrochemical stability, which makes the material a suitable electrode material for various applications such as bioelectrochemical applications and water disinfection.
In this paper, we had succeeded to generate ozone by using the BDD electrode with high efficiency compared to traditional lead oxide (PbO2) and other BDD electrods.
Firstly, a Titanium substrate had been seeded by ultra sonic agitation with diamond powder(30nm ~ 40nm) for an hour, which was used as a nucleation of diamond. After that BDD film was deposited on the substrate by microwave plasma chemical vapor deposition.
The morphology of samples was observed by Scanning Electron Microscopy (SEM) and the structural-chemical properties of synthesized diamond layer was investigated by Raman Spectroscopy. Conductivity, carrier concentration and Hall mobility was then determined by a Hall-effect measurement unit, based on the van der Pauw method. The ozone concentration in water, which was measured by Ozone Colorimeter.