bluuebunny/crossref_metadata_2025_split huggingface dataset:
(ECS Toyota Young Investigator Fellowship Program Address) Electrochemical Reduction of CO2(aq) By Solvated Electrons at a Plasma-Liquid Interface
Authors: Rumbach Paul , Xu Rui , Go David B. 
Published: February 2020

While electron transfer reactions typically occur at the interface between a reactant and a metal in an electrolyte solution, it is also possible to initiate these reactions at the interface between a plasma (gas discharge) and a solution. In this case, a free, gaseous electron is injected into the solution from the plasma phase, solvating before reacting away. In our previous work, we have shown that an atmospheric pressure plasma in argon can be used as a cathode in an electrolytic cell to produce solvated electrons[1]. In this work, we show that the solvated electrons produced by the plasma cathode can be used to reduce dissolved carbon dioxide, CO2(aq), to form the carboxyl radical anion, CO2
–
(aq). The CO2
–
(aq) radical can either recombine to form oxalate under basic conditions or react with H+
(aq) to produce formate under acidic conditions. We measure the Faradaic yield of both oxalate and formate formation using liquid ion chromatography and show that it is dictated by the well-known reaction kinetics of solvated electrons and CO2
–
(aq). Importantly, these 3-dimensional reaction kinetics are distinct from the 2-dimensional kinetics found in traditional electrochemistry and catalysis, and may open up new opportunities to explore electrochemical carbon dioxide reforming.

[1]P. Rumbach, D.M. Bartels, R.M. Sankaran, and D.B. Go, Nature Comm.
6, 7248 (2015).
Electrocatalytic Mineralization of Urea in Aqueous Medium By Means of Ni(II)Cyclam-Modified Nanoparticulate TiO2 Anodes and Simultaneous Electrogeneration of H2 on Pt Cathodes
Authors: Murcio-Hernández Saacnhitee , Gonzalez Nava Catalina , Perez J. J. , Torres-González Julieta , Sepúlveda Selene , Godínez Mora-Tovar Luis Arturo , Rodriguez Valadez Francisco Javier , Rodríguez-García Adrián , Manríquez Juan 
Published: February 2020

In this investigation we studied the electrocatalytic mineralization of urea contained in alkaline aqueous medium by means of Ni(II)cyclam-modified nanoparticulate TiO2 films (OTE/TiO2/Ni(II)cyclam, where an optically transparent electrode OTE was utilized as electrons collector) and the simultaneous electrogeneration of H2 through the H2O reduction on Pt cathodes which were inserted in the same cell. Our results showed that the standard potential for the H2 evolution (E°H2O/
H2 = -0.83V vs. NHE) was achieved on the Pt cathode when a potential of 1.0V vs. NHE was applied to the OTE/TiO2/Ni(II)cyclam//electrolyte interface (where the urea mineralization was taking place). On the contrary, the standard potential for the H2 evolution was achieved on the same Pt electrode when a potential of 1.2V vs. NHE was applied to the OTE/Ni(II)cyclam//electrolyte interface (in the absence of TiO2). These interesting results demonstrated that the urea oxidation potential on Ni(II)cyclam-modified OTEs was 0.2V cathodically-shifted in the presence of nanoparticulate TiO2.
Furthermore, H2 was continuously evolved for 1h from Pt cathodes in three-electrodes cells where aqueous urea solutions were simultaneously electrolyzed on OTE/TiO2/Ni(II)cyclam or OTE/Ni(II)cyclam electrodes. Interestingly, measurements of total organic carbon (TOC) which were carried out in the urea solutions with and without electrolytic treatment, revealed that the H2 evolution proceeds on a Pt cathode when the mineralization of urea achieves efficiencies of 20.8 and 10.4% on OTE/TiO2/Ni(II)cyclam and OTE/Ni(II)cyclam electrodes, respectively. These new results demonstrate that the OTE/TiO2/Ni(II)cyclam electrodes represents a novel pathway to carry out the electrochemical generation of H2 from urea as energy carrier.
Highly Sensitive and Selective Gas Sensors Based on Oxide Nanomaterials for Electronic Nose
Authors: Shim Young-Seok 
Published: February 2020

The functional convergence of the Internet with radio-frequency identification and sensors has led to the era of the Internet of Things (IoT), which is a computing concept in which everyday objects are online and communicate via the Internet. In particular, the IoT is effective and appropriate for monitoring and controlling objects in hazardous environments to enable people to access them. In order to apply gas sensors to the IoT, operation at room temperature (low power consumption), a high efficiency (sensitivity, response/recovery time, and stability), low-cost fabrication, miniaturization, and easy integration with circuits are essential because these factors enhance the feasibility of utilizing a gas sensor, thereby enabling the collection, processing, analysis, and dissemination of valuable information gathered from a variety of environments. Among various types of gas sensors, semiconducting gas sensors based on various metal oxides are considered to be the strongest candidate for the application in IoT owing to their small size, simplicity in operation, low cost, and compatibility with integrated circuits. A wide variety of nanostructured metal oxides, including nanowire, nanobelt, nanorods, nanosheets, nanospheres, and nanotubes has been exploited for semiconductor gas sensors during the past decade. Despite these efforts, achieving a reproducible fabrication, easy integration with other circuits, and compatibility with well-established semiconductor production processes that are related to mass production have remained challenges for the utilization of the semiconducting sensors in the IoT.
In the presentation, we show our research efforts to synthesize well-ordered metal-oxide nanostructures such as nanorods, nanohemispheres, nanospheres and nanowells using physical vapor deposition (PVD) methods for the high performance chemoresistive gas sensors.
(Invited) Chip Based Electrochemical Imaging of Neuron Transmitters Expression at Single PC12 Cell and 3-D Spheroids Level
Authors: Li Chen Zhong , Shah Pratikkumar , Ino Kosuke , Matsue Tomokazu , Yue Qiaoli , Chen Chunying 
Published: February 2020

Understanding and controlling the interface between neuronal cells and neuronal network and electrical devices is vital to both biological science and technology. Recent developments in the field of in vitro neuron mapping focus on the development of optical and electrochemical strategies for either single neuron cell/neuron measurement or artificial neuronal networks/brain slices mapping. To mimic in vivo neuronal networks and to elucidate the mechanisms of computation, spontaneous and elicited electrical activity need to be monitored, and multiple simultaneous recordings are required for monitoring individual unit and collective network activity. In this way, both individual cells and cell networks can be scrutinized in order to understand how changes in single unit activity and functionality. In the present study, we developed a large-scale integration -based amperometric sensor array system for electrochemical bioimaging and throughput sensing of dopamine expression from three-dimensional (3D)-cultured PC12 cells upon dopaminergic drugs exposure. It has been shown that individual cells behave differently from the population even under the identical conditions, as a complementary study, we also explore the possibility of single cell-on-chip based analytical technique which can collect real-time change in cell physiology by measurement of cell exocytosis, i.e., release of neurotransmitters, in a neuronal model cell line, i.e. PC12 cells. The study of single cell dynamics could help us better understand the complex processes, such as, neurotransmitter kinetics, ion channel functions, and cell communications, single cell analysis can be an equivalent and complementary strategy to existing approaches.
Electrochemical Detection of Bacteria Using Portable Paper-Based Culture Devices
Authors: Deiss Frédérique , Metangmo Armelle 
Published: February 2020

Testing of food and water samples for viruses and bacteria in a rapid, portable, quantitative way is of growing interest as much for government, farmers, industrials, as end-consumers. In the past two decades, many research groups were involved in the development of various paper-based devices for quantitative or semi-quantitative detection of clinically relevant analytes and in particular pathogens.
Some difficulties remain in analyzing samples with complex matrices (e.g., colored samples or muddy water), with enough sensitivity (e.g., detecting less than 10-100 cfu/mL) while minimizing culture time. Electrochemical detection can allow for rapid quantification over a wide dynamic range, with a low limit of detection, and without limitations related to presence of colors or particles in samples. Derda and co-workers validated growth of bacteria in portable paper-based culture devices [1, 2]. We added screen-printed electrodes onto those paper-based devices (Figure A-B) to allow for electrochemical detection of micro-organisms. The presence of bacteria in the device, and particularly on the electrode, bacteria affects the characteristics of the electrode. By measuring those changes by electrochemical impedance spectroscopy, for example, we could detect the bacteria (Figure E).
The platform can be selective to bacteria by immobilizing on the electrode proximity antibodies specific to the bacteria to detect, and thus enhancing the presence of the bacteria on the electrode.
Using the paper-based portable culture device instead of metal electrodes as reported previously [3] as a support as multiple advantages: in addition to allow for an easy- sampling at the point-of-care or in-field, if the sample has a low number of bacteria (Figure C), it can be cultured in the same device and tested again once more bacteria is present (Figure D) without additional handling of the sample. The use of paper in these devices made them user-friendly, portable, light-weight, low-cost, easy to manufactured and disposed of once contaminated (e.g., burning).
References
1. Deiss, F.; Funes-Huacca, M. E.; Bal, J.; Tjhung, K. F.; Derda, R., Antimicrobial susceptibility assays in paper-based portable culture devices. Lab on a Chip
2014,14, (1), 167.
2. Funes-Huacca, M.; Wu, A.; Szepesvari, E.; Rajendran, P.; Kwan-Wong, N.; Razgulin, A.; Shen, Y.; Kagira, J.; Campbell, R.; Derda, R., Portable self-contained cultures for phage and bacteria made of paper and tape. Lab on a Chip
2012,12, (21), 4269.
3. Lu, L.; Chee, G.; Yamada, K.; Jun, S., Electrochemical impedance spectroscopic technique with a functionalized microwire sensor for rapid detection of foodbornepathogens. Biosensors and Bioelectronics
2013, 42, (0), 492.

Figure 1
Electron Transfer Studies Between New Fad-Dependent Glucose Dehydrogenase and Different Osmium Polymers (Applications in biosensors and biofuel cells)
Authors: Aslam Iqra , Zafar Muhammad Nadeem , Ludwig Roland , Leech Dónal , Gorton Lo 
Published: February 2020

A new extracellular flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase from Glomerella cingulata (GcGDH) was electrochemically studied as a recognition element in glucose biosensors. The redox enzyme was recombinantly produced in Pichia pastoris, homogeneously purified and its glucose oxidizing properties on spectrographic graphite electrodes were investigated. Six different Os-polymers, the redox potentials of which ranging in a broad potential window between +15 and +489 mV vs. NHE, were used to immobilize and “wire” GcGDH to the spectrographic graphite electrode’s surface. The GcGDH/Os-polymer modified electrodes were evaluated by chronoamperometry using flow injection analysis. The current response was investigated using a step-wisely increased applied potential. It was observed that the ratio of GcGDH:Os-polymer and the overall loading of the enzyme electrode significantly affect the performance of the enzyme electrode for glucose oxidation. The best suited Os-polymer [Os(4,4¢-dimethyl-2,2¢-bipyridine)2(PVI)Cl]+ had a potential of +309 mV vs. NHE and the optimum GcGDH:Os-polymer ratio was 1:2 yielding a maximum current density of 493 µAcm-2 at a 30 mM glucose concentration.

Key words: Glucose dehydrogenase, FAD, Os-polymers, glucose biosensor, chronoamperometry, oxygen reactivity.
Comparative Electroanalytical Study on Fabrication of CN Selective Sensor Based on Polymeric Membrane Electrode and Coated Graphite Electrode
Authors: Singh Ashok KUMAR , Bhardwaj Shubhrajyotsna 
Published: February 2020

The construction and general performance characteristics of PVC-based cyanide selective polymeric membrane electrode (PME) and coated graphite electrode (CGE) incorporating the synthesized 2,4-di-tert-butyl-6-((2(2,4-dinitrophenyl)hydrazono)methyl)phenol (I) is described here. Effect of various plasticizers (o-nitrophenyloctyl ether, oleic acid, dibutylsebacate, dibutylphthalate, tri-n-butylphosphate) and cation excluder, Cetryltrimethylammoniumbromide (CTAB) was studied by constructing membranes having different compositions. The best performance was observed for the membrane having composition of I: PVC: oNPOE: CTAB ratio of 3.5: 36: 58: 2.5 (w/w; mg). So the coated graphite electrode (CGE) using same composition was also constructed and the sensor displays significantly improved selectivity towards CN‾ion. The response features of PME based on the above stated membrane composition was also compared with CGE. The electrode exhibits Nernstian slope for CN‾ions over wide concentration ranges i.e. 8.3 × 10-6 to 1.0 × 10-1 mol L-1 (with PME) and 5.87×10-7 – 1.0×10-1 mol L-1 (with CGE) and response time of 13 s and 10 s for PME and CGE respectively. CGE exhibits low detection limit 3.6×10-8 mol L-1 with Nernstian slope -58.8 ± 0.2 mV decade-1. Furthermore, the electrode shows constant potentials in the pH range of 6-8 and can be used for about 3 months without any significant deviation in their potential response. The selectivity of the sensor is fairly good over most common anions. The extraordinary selectivity of CGE for CN‾ion permits its practice in the determination of CN‾ion in water and edible samples. Practice of the sensor for potentiometric detection of microgram measures of CN‾ion displays an average regaining of 99.5% and a mean standard deviation of 0.5% and the results attained are comparable with those delivered by AAS analysis.
The Decomposition Mechanism of Crystalline Lioh on Ruthenium in Non-Aqueous Lithium-Oxygen Batteries: A First-Principles Study
Authors: Jiang Haoran , Zhao Tianshou 
Published: February 2020

Non-aqueous lithium-oxygen (Li-O2) batteries are considered as the potential energy storage system for electric vehicles due to its comparable energy density (11682 W h kg-1) with gasoline (13000 W h kg-1) [1]. However, the development of Li-O2 batteries is still at its early stage and suffers from some critical issues, such as short cycle life, poor electrolyte and electrode stabilities, and low energy efficiency [2], most of which are related to the high charge overpotential during the oxygen evolution reaction (OER). One widely applied approach to decrease the high charge overpotential is using catalyst, such as carbon-based materials, noble metals, metal oxides and so on. Even with this effort, however, it is still difficult to lower the charge voltage as much as possible (e.g. 3.5 V) to ensure the stabilities of electrolyte and electrode materials when Li2O2 is the discharge product [3]. Recently, an alternative strategy that achieves an ultra-low charge ovepotential and excellent stability has been reported, which is to form solid-state LiOH rather than Li2O2in the discharge process [4, 5]. However, the mechanism of crystalline LiOH decomposition on catalysts is still unknown, and the possible catalysts that can promote the decomposition of solid-state LiOH are also limited.
In this regard, a first-principles study was used to investigate the OER process in non-aqueous Li-O2batteries via LiOH formation and decomposition. We developed an interfacial model to study the decomposition mechanism of LiOH on different surfaces of ruthenium, and the charge overpotentials among different surfaces were compared. Moreover, the decomposition path of crystalline LiOH and the rate determining step (RDS) were investigated. Our results demonstrate the activity of ruthenium towards the decomposition of crystalline LiOH, and different surfaces can lead to the different decomposition paths.
Further analysis of the decomposition mechanism of crystalline LiOH will be presented at the meeting. Our investigations give new insight into the future catalyst design in non-aqueous Li-O2batteries.

References

[1] G. Girishkumar, B. McCloskey, A. Luntz, S. Swanson and W. Wilcke, The Journal of Physical Chemistry Letters, vol. 1, pp. 2193-2203, 2010.
[2] J. Christensen, P. Albertus, R. S. Sanchez-Carrera, T. Lohmann, B. Kozinsky, R. Liedtke, J. Ahmed and A. Kojic, J. Electrochem. Soc., vol. 159, pp. R1-R30, 2011.
[3] M. M. Ottakam Thotiyl, S. A. Freunberger, Z. Peng and P. G. Bruce, J. Am. Chem. Soc., vol. 135, pp. 494-500, 2012.
[4] F. Li, S. Wu, T. Zhang, P. He, A. Yamada and H. Zhou, Nature Communications, vol. 6, 2015.
[5] T. Liu, M. Leskes, W. Yu, A. J. Moore, L. Zhou, P. M. Bayley, G. Kim and C. P. Grey, Science, vol. 350, pp. 530-533, Oct 30, 2015.
The Effect of Chemical Doping on the Lithiation Processes of the Crystalline Si Anode: A First-Principles Study
Authors: Kuo Chin-Lung , Chiang Han-Hsin 
Published: February 2020

In this study, we have performed density functional theory calculations and ab initio molecular dynamic simulations to investigate the kinetics and dynamics of the lithiation processes of the doped and undoped c-Si anodes for their application in Li-ion batteries. Our ab initio molecular dynamic simulations showed that the lithiation process of c-Si can be remarkably improved by phosphorus-doping while that for the boron-doped Si is simply comparable to the performance of the undoped Si electrode. To explore the physical origins of the enhanced rate capability of the phosphorus-doped Si anode, we calculated the insertion and migration energy barriers of Li ions in c-Si, and then simulated the mechanical response of the Li-inserted Si matrix under different hydrostatic stresses. Our calculated results showed that boron-doping can effectively lower down the insertion barrier of a Li atom into the Si-matrix but phosphorus-doping may lead to the increment of the Li insertion energy in c-Si. Furthermore, although the diffusion energy barriers of Li may slightly decrease (increase) by ~0.2 eV in the phosphorus (boron)-doped Si matrix, these changes were found to be highly localized within the range of the nearest-neighbor distance. Accordingly, the enhanced lithiation rate in the phosphorus-doped Si electrode cannot be attributed to the increased Li diffusion rate or the reduction of the insertion energy barriers of Li atom into the c-Si electrode. On the other hand, our calculated mechanical response of the Li-inserted Si matrix showed that the phosphorus-doped Si matrix can become more ductile and more easily undergo plastic deformation upon hydrostatic stresses, but on the contrary, the Si matrix may become more brittle and stiffer as it was doped with boron atoms. Our ab initio molecular dynamic simulations also showed that the phosphorus-doped Li-inserted Si matrix can easily undergo structure amorphorization within 10 ps, but the boron-doped and undoped Si matrices can still or mostly hold in the diamond structures within the same elapsed time of MD simulations. These results clearly indicate that mechanical softening of the Si bond network can be one of the major reasons that leads to the enhanced lithiation rate of the phosphorus-doped Si electrode.
(Invited) Glimmers of New Point-of-Care Sensors through the Patent Thicket
Authors: Cunningham David Dean , Smith Connor T. , Miller Courtney N. 
Published: February 2020

Commercially successful sensors used in the Point-of-Care market involve integration of sensitive sensor components into robust analytical systems. Technologies incorporated into these systems generally converge upon a very small number of methodologies compared with the large variety reported in journals and patents. Sorting through this literature to discern which innovations might appear in commercial products is a daunting task. One useful tool is analysis of the intellectual landscape via free patent searches, but the product of these efforts can lack organization. Relationships been technologies have often been depicted in patent maps which focus on technologies, products and ownership. Newly emerging tools in this realm will be described to identify market leaders, innovators and explorers.
Early identification of important new advances also depends on a firm understanding of the capabilities of sensors currently on the market. Current products can be broadly divided into detection of ions, small molecules and proteins. A review of products in these categories will be provided to allow assessment of the potential for new technologies that may impact or disrupt the field. Several potentially disruptive electrochemical technologies including digital microfluidic immunoassays will be described. Finally, relatively incremental, but effective, examples of advances in multi-enzymatic amperometric systems and their incorporation into robust polymer formulations will be presented. Combining the analysis of emerging intellectual property and experimental studies is suggested as a powerful approach for identifying areas ripe for discovery, as well as predicting the future trajectory of new products.
Fe3O4 on Graphene Oxide Nanosheets for Electrochemiocal Detection of Cancer Biomarker Proteins
Authors: Sharafeldin Mohamed , Bishop Gregory William , Bhakta Snehasis , Rusling James F 
Published: February 2020

An ultrasensitive mediator-free electrochemical detection method for proteins has been developed on an 8-sensors microfluidic platform. In this method, a sandwich immunoassay approach was used to detect prostate cancer biomarkers on screen-printed carbon electrodes. Fe3O4 nanoparticles with peroxidase like-activity were loaded onto graphene oxide nano-sheets resulting in a Fe3O4@GO composite with 1 µm average diameter as determined by dynamic light scattering and electron microscopy. Voltammetric studies and colorimetric assays confirmed the Fe3O4@GO composite material exhibited catalytic activity toward hydrogen peroxide reduction. Detection antibodies were covalently attached to Fe3O4@GO composite, the resulting biocomposite was used as a detection label in sandwich immunoassays for Prostate Specific Antigen (PSA) and Prostate Specific Membrane antigen (PSMA). The sensor surfaces of the array were coated with electrochemically reduced graphene oxide to improve conductivity and increase surface area, and then capture antibodies were attached through either adsorption or covalent binding to residual carboxylic groups on surface. An optimized simple microfluidic system was used to deliver reagents to the electrode arrays and wash/remove unbound species. This sandwich assay based on catalytic reduction of hydrogen peroxide by Fe3O4@GO detection labels exhibited detection limits of 61 fg/mL for PSA and 9.8 fg /mL for PSMA.