Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
V. Sankar, E. Patrick, Robert Dieme et al.
Frontiers in Neuroengineering · 2014
Changes in biotic and abiotic factors can be reflected in the complex impedance spectrum of the microelectrodes chronically implanted into the neural tissue. The recording surface of the tungsten electrode in vivo undergoes abiotic changes due to recording site corrosion and insulation delamination as well as biotic changes due to tissue encapsulation as a result of the foreign body immune response. We reported earlier that large changes in electrode impedance measured at 1 kHz were correlated with poor electrode functional performance, quantified through electrophysiological recordings during the chronic lifetime of the electrode. There is a need to identity the factors that contribute to the chronic impedance variation. In this work, we use numerical simulation and regression to equivalent circuit models to evaluate both the abiotic and biotic contributions to the impedance response over chronic implant duration. COMSOL® simulation of abiotic electrode morphology changes provide a possible explanation for the decrease in the electrode impedance at long implant duration while biotic changes play an important role in the large increase in impedance observed initially.
Belkacem El Amrani
Preprints.org · 2024
Ectomycorrhizal (EM) associations are essential symbiotic relationships that contribute significantly to the health and functioning of forest ecosystems. This review examines the biotic factors that influence EM associations, focusing on plant and fungal diversity, host specificity, and microbial interactions. Firstly, the diversity of host plants and ectomycorrhizal fungi (EMF) is discussed, highlighting how the richness of these organisms affects the formation and success of EM symbioses. Next, host specificity is explored, with a focus on the complex relationships between EMF and their host plants. Microbial interactions are examined in depth, with sections on both positive and negative influences of bacteria and different fungal groups on EM formation. Overall, this review provides a comprehensive overview of the biotic factors that shape EM associations, offering insights into the mechanisms that underpin these critical ecological interactions and their broader implications for ecosystem management and restoration.
Vamsi J. Nalam
· 2012
The activity of plant 9-lipoxygenases (LOXs) influences the outcome of Arabidopsis thaliana interaction with pathogen and insects. Evidence provided here indicates that in Arabidopsis, 9-LOXs facilitate infestation by Myzus persicae, commonly known as the green peach aphid (GPA), a sap-sucking insect, and infection by the fungal pathogen Fusarium graminearum. in comparison to the wild-type plant, lox5 mutants, which are deficient in a 9-lipoxygenase, GPA population was smaller and the insect spent less time feeding from sieve elements and xylem, thus resulting in reduced water content and fecundity of GPA. LOX5 expression is induced rapidly in roots of GPA-infested plants. This increase in LOX5 expression is paralleled by an increase in LOX5-synthesized oxylipins in the root and petiole exudates of GPA-infested plants. Micrografting experiments demonstrated that GPA population size was smaller on plants in which the roots were of the lox5 mutant genotype. Exogenous treatment of lox5 mutant roots with 9-hydroxyoctadecanoic acid restored water content and population size of GPA on lox5 mutants. Together, these results suggest that LOX5 genotype in roots is critical for facilitating insect infestation of Arabidopsis. in Arabidopsis, 9-LOX function is also required for facilitating infection by F. graminearum, which is a leading cause of Fusarium head blight (FHB) disease in wheat and other small grain crops. Loss of LOX1 and LOX5 function resulted in enhanced resistance to F. graminearum infection. Similarly in wheat, RNA interference mediated silencing of the 9-LOX homolog TaLpx1, resulted in enhanced resistance to F. graminearum. Experiments in Arabidopsis indicate that 9-LOXs promote susceptibility to this fungus by suppressing the activation of salicylic acid-mediated defense responses that are important for basal resistance to this fungus. the lox1 and lox5 mutants were also compromised for systemic acquired resistance (SAR), an inducible defense mechanism that is systemically activated throughout a plant in response to a localized infection. the lox1 and lox5 mutants exhibited reduced cell death and delayed hypersensitive response when challenged with an avirulent strain of the bacterial pathogen Pseudomonas syringae pv tomato. LOX1 and LOX5 functions were further required for the synthesis as well as perception of a SAR-inducing activity present in petiole exudates collected from wild-type avirulent pathogen-challenged leaves. Taken together, results presented here demonstrate that 9-LOX contribute to host susceptibility as well as defense against different biotic stressors.
A E Nicholson, N J Mayne
Monthly Notices of the Royal Astronomical Society · 2023
ABSTRACT The search for biosignatures necessitates developing our understanding of life under different conditions. If life can influence the climate evolution of its planet then understanding the behaviour of life-climate feedbacks under extreme conditions is key to determine the ‘edges’ of the habitable zone. Additionally understanding the behaviour of a temperature limited biosphere will help towards formulating biosignature predictions for alien life living under conditions very different to those on Earth. Towards this aim, we extend the ‘ExoGaia Model’ – an abstract model of microbial life living on a highly simplified zero-dimensional planet. Via their metabolisms, microbes influence the atmospheric composition and therefore the temperature of the planet and emergent feedback loops allow microbes to regulate their climate and maintain long-term habitability. Here, we adapt the ExoGaia model to include temperature adaptation of the microbes by allowing different species to have different temperature ‘preferences’. We find that rather than adapting towards the planet’s abiotic conditions the biosphere tends to more strongly influence the climate of its planet, suggesting that the surface temperature of an inhabited planet might be significantly different from that predicted using abiotic models. We find that the success rate for microbial establishment on planets is improved when adaptation is allowed. However, planetary abiotic context is important for determining whether overall survival prospects for life will be improved or degraded. These results indicate the necessity to develop an understanding of life living under different limiting regimes to form predictions for the boundaries of the habitable zone.
Nripendra Laskar
· 2017
“The present book "Current Trends in Global Environment" deals with each and every important and recent issue of environment with clear-cut facts in a lucid manner of presentation, which are likely to be come across by its readers, irrespective of their discipline. An attempt has been made to present the matter in a perceptible and comprehensible manner which would be equally important to a beginner and specialist. Worthy for a reference for its up-to-date content that satisfy its user in a minimum of time. By far majority of books are from the mainstream with heavy a textual load. It has s on present day burning topics like The Greenhouse Effect, Natural Disasters i.e., Tsunami, Earthquake, Continental Drift, Sustainable Environment, Space Ecology, The Glossary will be useful for an individual new to the subject and anyone inexperienced in dealing with some aspects of the subjects. The index has been designed with upper most principle that it should be as complete as possible, of words and short phrases as they naturally appear in related species. We hope that his Global publication by a global famed personality will fit the subject gap for the readers and above all institutional libraries.
Eric Post
Princeton University Press eBooks · 2013
Rising temperatures are affecting organisms in all of Earth's biomes, but the complexity of ecological responses to climate change has hampered the development of a conceptually unified treatment of them. In a remarkably comprehensive synthesis, this book presents past, ongoing, and future ecological responses to climate change in the context of two simplifying hypotheses, facilitation and interference, arguing that biotic interactions may be the primary driver of ecological responses to climate change across all levels of biological organization. The author's synthesis and analyses of ecological consequences of climate change extend from the Late Pleistocene to the present, and through the next century of projected warming. The book's investigation is grounded in classic themes of enduring interest in ecology, but developed around novel conceptual and mathematical models of observed and predicted dynamics. Using stability theory as a recurring theme, the book argues that the magnitude of climatic variability may be just as important as the magnitude and direction of change in determining whether populations, communities, and species persist. It urges a more refined consideration of species interactions, emphasizing important distinctions between lateral and vertical interactions and their disparate roles in shaping responses of populations, communities, and ecosystems to climate change.
Dong Suk Han, Celal Erbay, Choongho Yu et al.
Qatar Foundation Annual Research Conference Proceedings Volume 2016 Issue 1 · 2016
In the past decades, microbial fuel cells (MFCs) have been intensively studied in order to provide sustainable and environmentally friendly wastewater treatment concurrent with energy harvesting. A highly porous, highly efficient, light-weight, and inexpensive 3D sponges consisting of interconnected carbon nanotubes (CNTs) were developed as anodes of MFCs in order to allow more efficient microbe-to-anode electron transfer that are key to the operation of MFCs. The MFCs equipped with the 3D CNT sponge anode generates high power densities of 2150 Wm –3 (per anode volume) or 170 Wm –3 (per anode chamber volume), comparable to those of commercial 3D carbon felt electrodes under the same conditions (1). The high performances are due to excellent charge transfer between CNTs and microbes, which is evident by the 13 times lower charge transfer resistance compared to that of carbon felt. The 3D CNT sponges produced here has low cost (∼$0.1/gCNT) and high production rate (3.6 g/hr) compared to typical production rate of 0.02 g/hr of other CNT-based materials (1). The high production rate and low cost of this highly efficient electrode material can make MFCs more feasible to be scaled up for various applications such as desalination of seawater or saline water. Also, other electrode materials were compared to the 3D CNT sponge in evaluating the efficiency of the MFC and extending the use of these electrode materials to a field of microbial desalination cell (MDC). Once MDCs are applied to the desalination process, there are several challenges that need to be addressed. First, a pH gradient forms between anode and cathode chambers (due to proton accumulation in the anode chamber and hydroxyl ion accumulation in the cathode chamber). In addition, chloride ion accumulation inhibits the activities of electrochemically active microbes. Together these activities degrade the overall performance of the system. Recirculation of the anolyte and catholyte provides one solution to addressing this challenge. However, this approach results in lower Coulombic efficiency. Here, we studied to develop a modified three-chamber configuration where part of the anode chamber and part of the cathode chamber are directly connected through a cation exchange membrane, thus partially allowing transport of protons between the chambers, and thereby limiting the drop in pH, while still maintaining charge differences that drive Cl – and Na + ions to move from seawater to the anode and cathode chambers. Practical MDCs require continuous or batch-mode feeding of wastewater into the anode chambers of the system, thus accumulated chloride ions will be simply flushed out or diluted due to the influx of new wastewater or catholyte. This aspect will mitigate the impacts of the chlorine ion accumulation problem. Also, a pivotal performance limitation centers on the cathode catalyst layer owing to sluggish kinetics of the oxygen reduction reaction and several transport losses. On the cathode side, expensive precious metal catalysts have been used in conventional systems to overcome the slow reactions on the electrode. Platinum and Pt-based electrocatalysts, commonly used in the electrodes, not only contribute to high fuel cell cost but also lead to durability concerns in terms of Pt cathode oxidation, catalyst migration, loss of electrode active surface area, and corrosion of the carbon support. So, this study used Pt-free 3D carbon-based cathode for MDC system. Reference [1] Celal Erbay, Gang Yang, Paul de Figueiredo, Reza Dadr, Choongho Yu, Arum Han, “Three-dimensional porous carbon nanotube sponges for high-performance anodes of microbial fuel cells”, Journal of Power Sources, (2015), 177–183.
Andrew Needham
Power Lines · 2014
This chapter addresses how The New York Times challenged the long-held claims of Arizona officials that their state was entitled to a portion of the Colorado River by rights, a claim recently upheld by the Supreme Court. The paper also argued that Arizona's attempt to realize those claims endangered the Colorado River and the Grand Canyon itself. Transforming the flowing energy of water into flowing electricity, the Times suggested, was not in the national interest. Such critiques of Arizona's growth emerged in the wake of the Interior Department's development of the Pacific Southwest Water Plan, a plan designed in 1963 to realize Arizona's Colorado River claims. The critiques emerged from several different conservationist groups, but most powerfully from the Sierra Club, which was gradually changing the description of its politics from “conservation” to “environmentalism” and assuming a far more public voice in disputes over the proper use of public lands.
Kyung Lee, Keum Sook Kim, suw young Ly
Preprints.org · 2024
Background/Objective: In-vivo diabetes detection of glucose were sought using square-wave anodic stripping voltammetry (SW), with bismuth-immobilized carbon nanotube paste electrode (BCE). Methods: The optimum analytical results indicated sensitive peak signals on the BCE. The raw voltammogram was approached within the 1 mgL-1-14 mgL-1 and 10 ugL-1-140 ugL-1, detection limits with preconcentration times of 100 and 200 sec. Results: The relative standard deviation was 0.02 % (n = 15) of 10.0 mgL-1 under optimum conditions. The analytical detection limit (S/N) was attained at 8 ugL-1. The handmade microsensor was directly used in vivo on the living fish brain and human urine.Conclusion: The method was applied at real time in vivo, without requiring any pretreatment and other ionic electrolyte solutions. It can be used for medicinal and other materials requiring biological-fluid detection in real time. This study was designed to be suitable for real-time unmanned remote diagnosis and therapeutic drug injection into the body, micro-needle long-term administration, wearable artificial skin tattoo sensor, and real-time control. In addition, the glasses monitor was designed to be suitable for multitasking and multi-user control.
Leyla Mirhashimli, Afag Hasanova, A. Choriev
BIO Web of Conferences · 2025
The internationalization of the banking sector in developing countries brings both significant benefits and challenges. Foreign banks promote competition, efficiency and financial inclusion, which accelerates the integration of local banking systems into the global economy. However, the arrival of large international players may increase risks and force local banks to make significant changes. Studies show that the influence of foreign banks is ambiguous and depends on the level of economic development of the country. When assessing the effects of globalization, it is important to consider the differences between developed and developing countries. In periods of economic crisis, foreign banks can play a stabilizing role, but they can also import shocks from their own countries. To maximize benefits and minimize risks, it is necessary to develop a strategy that ensures a balanced presence of foreign banks, supports competition and innovation, but does not allow excessive concentration of bank capital. In this context, the internationalization of financial services becomes an important tool for strengthening and liberalizing the financial systems of developing countries, opening new opportunities for their economic growth and sustainable development. Since the collapse of the Bretton Woods system and the beginning of the era of financial liberalization, one of the most important manifestations of the process of integration of the banking sector into the world economy has been the expansion of foreign banking capital into foreign markets. Financial sector liberalization is intended to provide equal opportunities for financial institutions to access the international market or reduce restrictions from local regulators. Liberalization of the banking industry is one of the most important financial sector liberalization programs.
Dominique Larcher, Jennyfer Miot, Nadir Recham et al.
ECS Meeting Abstracts · 2014
Presently, the production of high-energy Li-ion based storage systems comes with large energy consumption and environmental impact, the most being the production of the electrode materials because of the high temperatures generally required and of the chemical nature of their components (transition metals). The main approaches explored to tackle this issue are i) finding new materials, enlisting alternative redox centers such as organics ii) exploring new synthetic ways using much lower temperatures iii) looking for efficient recycling processes. Living (i.e. aquatic) beings, owing to specific enzymatic-based metabolisms, are able to spontaneously trap, concentrate and transform soluble species, leading to precipitates (e.g. oxides, phosphates, carbonates …) with specific size, texture, morphology, at ambient temperature. In this study, we will exemplify the benefit of using bacteria to produce highly textured Fe-oxides and Fe-phosphates providing improved cyclability and power capability when reacted with lithium. Firstly, we report a method based on bacterial iron biomineralization for the synthesis of a-Fe 2 O 3 as conversion electrode material. This high-yield (> 80%) synthesis approach enlists (1) the room temperature formation of g-FeOOH via the use of the anaerobic Fe(II)-oxidizing bacteria Acidovorax sp . strain BoFeN1, and (2) the transformation of these BoFeN1 / g-FeOOH assemblies into an alveolar bacteria-free a-Fe 2 O 3 material by a short heat treatment under air. As the g-FeOOH precursor particles are preferentially precipitated between the two membranes of the bacteria cell wall (40-nm thick space), the final material consists of highly monodisperse nanometric (~ 40 x 15 nm) and oriented hematite crystals, assembled to form a hollow shell having the same size and shape as the initial bacteria (bacteriomorph) (Figure 1) . Besides X-Ray and electron diffraction studies, electrochemical galvonastatic signatures vs. Li (down to 0 Volt) confirm the formation of hematite (Figure 2, left) . However, the capacity retention of the bacteriomorph samples is found to be largely improved in comparison with samples which organization was prior destroyed by hand-milling while not altering the size/structure of the primary oxide grains (Figure 2, center) . In addition, long cycling tests enlightened a progressive in-situ loss of the bacteriomorph organization that correlates the observed long-term capacity decay. This original porous organization induced by the bacteria also positively impacts the power capability of the textured powder. Indeed, only 30% of the capacity is lost when cycling is performed from 1Li / 100 h to 1 Li / 6 min while the ground untextured powder is losing 85% of its initial and still low charge capacity (Figure 2, right) . Thanks to the dual textural control enabled by the bacteria (micrometric-level organization of nanometric primary grains), correlated enhanced reversibility and impressive high power capability could thus be achieved (J.Miot et al, Energy & Environmental Science 7(1), 451, 2014). Secondly, bacterially-induced eco-efficient and scalable room-temperature synthesis method can be applied to other systems, provided the bacteria strain is properly selected and adapted to the targeted material. For the room-temperature precipitation of Fe-based phosphates, Bacillus pasteurii was selected as its metabolism enlists urease enzyme controlling the decomposition of urea, thus the release ammonia in the medium, so finally its local pH. This allows the formation of nanometric and organized active grains (Figure 3) with specific assets towards Li-reactivity that will be also detailed.
Hidayati Istiqomah, Putri Anggun Puspitarini, Putty Ekadewi et al.
E3S Web of Conferences · 2018
One of the most promising areas with the existence of the lake is Universitas Indonesia. Universitas Indonesia (UI) has six lakes with a total area of 269,107 m 2 which is very important for its existence to balance the surrounding environment. Currently, the existence of UI lake has been contaminated with the COD value of about 1 to 8.000 mg/L due to a lot of garbage that enters and buried in it, that more attention is needed so that pollution will not increase. Microbial Desalination Cell (MDC) is a development system of Microbial Fuel Cell (MFC), which has the ability to desalinate seawater and can produce electricity by using microorganisms as waste decomposers. In addition, MDC method can also reduce the level of waste contained in the substrate used. To improve the performance of MDC, this study utilizes bio charcoal from rice husks to assess the performance of sodium percarbonate in the cathode chamber with a variation of 0.05 M concentration; 0.1 M; 0.15 M; and 0.2 M, and the performance of the addition of bacteria consortium on the substrate. The best results of this MDC study, in the variation of 0.15 M sodium percarbonate concentration with a decrease of COD and BOD of 93.98% and 87.67% and in variation of addition of bacteria consortium of 1 mL with decrease of COD and BOD 90.04% and 50.52%.
A.B. Safarov, O.I. Rakhmatov, Yu.G. Uzakova
BIO Web of Conferences · 2023
The article presents the results of research on the possibilities of providing heat-cooling and electricity supply systems to autonomous consumers located far from centralized energy supply in the southern regions of Uzbekistan (Bukhara and Kashkadarya) based on renewable energy sources. In these regions, the average daily relative solar energy is 4.5 kWh/m 2 /day, the average wind speed is 5.5...8.5 m/s, the relative energy is 300...580 W/m 2 , and the underground low-potential temperature at a depth of 3...5 m, on average, is +10...+12 o C. Analyzes of scientific research conducted on the development and reliability of trigeneration systems in the world are presented, and the possibilities of using these systems in our region are based. A combined solar-wind power plant, which is adapted to the climatic conditions of the southern regions of Uzbekistan, works efficiently in weak wind currents and high temperature regimes, and a complex energy system consisting of geothermal heat pumps that produce continuous heat and cold energy in different temperature regimes is offered. The proposed complex power plant allows for continuous and reliable energy supply to autonomous consumers located far from the centralized energy supply.
Ozcan Ozmen, John Zondlo, Shiwoo Lee et al.
ECS Meeting Abstracts · 2015
Nano-catalyst infiltration within porous Solid Oxide Fuel Cells (SOFC’s) electrodes is a well-known process to increase electrochemical performance. Conventional dripping methods usually require multiple infiltration steps in order to achieve optimum catalyst loading. In this study, an alternative process was developed to efficiently infiltrate nano-catalyst into the NiO/YSZ anode of an anode-supported commercial SOFC. Mussel inspired catechol-based adhesives were used as a surfactant layer within the 3-D electrode architecture to better control the infiltration kinetics and dispersion of the nano-catalyst. The work assessed the use of adhesive molecules, polymerized dopamine (PDA) and/or nor-epinephrine (PNE), as the bio-template layer for either metal oxide or hydroxide deposition. The bio-template adhesiveness on the pore walls was shown to provide higher nano-catalyst loading by avoiding segregation of the precipitate within the porous structure, which usually results in the migration and preferential deposition of the solute at the surface (during the drying process). The first objective was to better understand the templating kinetics of PDA and PNE with altering processing variables (eg. pH, solid loading, immersion time, etc.), in order to control nano-catalyst deposition amount. The second objective was to control the catalyst grain growth rate by manipulating the level of nano-catalyst percolation and by altering the composition of the catalyst to hinder diffusion and grain boundary mobility. The process started by first immersing the cell into the polymerized template solution up to 24 h and then immersed directly into the catalyst precursor solution, with the same protocol. Cerium oxide was used as a demonstration catalyst composition for this work, but later work will focus on other catalyst compositions. A dip-coating process for the entire cell was used for this work in order to evaluate the possibility of infiltrating both the anode and cathode at the same time. The final step included a singular firing to 750 o C to form CeO 2 catalyst. In that case, only one thermal firing step was needed to achieve high solids loading levels, which is unlike conventional dripping methods where multiple thermal steps are required. A correlation between ~300 hour cell performance and nano-catalyst characterization was developed by I-V-P testing and impedance spectroscopy at various duration during the constant current loading. In one heat cycle, dopamine assisted dip-coated cells reached 1.1 mg to 1.6 mg deposition of nano-ceria incorporation (for the combined anode and cathode). The most promising of the protocols included a) ex-situ polymerization, (where the biotemplate solution was polymerized in a separate beaker before infiltration) and b) in-situ polymerization (where the biotemplate solution was polymerized when the cell was in the bio-template medium). These methods showed an initial increase of the maximum power density at 750°C using humidifed H 2 fuel by ~20.7 and 17.9%, respectively. However, the grain growth of the nano-catalyst within the in-situ polymerized fuel cell caused a decrease in performance from 11.5% to 5.6 % in 300 h. Also, PNE assisted dip-coating protocol resulted in the deposition of 1.8 mg of nano-ceria by the same process. The cell showed ~13.6% higher increase in the maximum power density at ~24 h, but the cell degraded and the maximum power density decreased to ~2.1% lower than the baseline cell performance. Future work is focusing upon methods to control the nano-catalyst growth at the operating temperature. Methods of controlling the grain boundary migration rate using various solid-solution or secondary phase stabilization strategies are currently being investigated in order to achieve long-term stability of the infiltrated cells. Acknowledgements: As part of the National Energy Technology Laboratory’s Regional University Alliance (NETL-RUA), a collaborative initiative of the NETL, this technical effort was performed under the RES contract DE-FE0004000. This project was funded by the Department of Energy, National Energy Technology Laboratory, an agency of the United States Government, through a support contract with URS Energy & Construction, Inc. Neither the United States Government nor any agency thereof, nor any of their employees, nor URS Energy & Construction, Inc., nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
G. Qin, Y.C. Ding, Ya Xiong Liu et al.
Materials Science Forum · 2009
In the treatment of disorders, bio-electrodes are used to be implanted into the patients’ deep brain for long-term stimulation. This paper presents a custom design and flexible fabrication process of bio-electrode for treating neural disorders using rapid prototyping (RP) technique. A 3D model of the bio-electrode is designed and the photosensitive resin electrode prototype is fabricated on the laser rapid prototyping machine, and then the bio-electrode is fabricated using this electrode prototype and the silicon rubber mold and winding technique. The spatial distribution of the electric field fabricated of the bio-electrode is analyzed, and the optical photomicrograph reveals that the cylindrical surfaces of the polyurethane of the bio-electrode have smooth surface and no visible microcracks, and the spiral lines are arranged densely and have no defects of loose and falling and partly protruding. The electrochemical experiments show that the electrochemical process of the bio-electrode is reversible and the bio-electrode has good functionality and stability property.
Nattakarn Wangfuengkanagul
· 2001
In this research, electrochemical analysis of drugs using a boron-doped diamond thin film electrode has been studied. Drugs, including acetaminophen, D-penicillamine and barbituric acid were investigated. The electrochemistry of drugs was studied by cyclic voltammetry. Comparison experiments were carried out using a polished glassy carbon (GC) electrode. At the diamond electrode, well-resolved cyclic voltammograms were obtained with current signal to background ratios higher than that obtained from the glassy carbon electrode. Detection limits of 10, 25 and 50 micrometre for acetaminophen, D-penicillamine and barbituric acid, respectively were obtained at the diamond electrode. Flow injection with amperometric detection using the diamond electrode was also studied. A significant low detection limit at 10 nM with signal to noise ratios higher than 3 and a linear range over 2-3 orders of magnitude were obtained. The purposed method was further applied to real drug samples in pharmaceutical preparations. These were paracetamol syrup and penicillamine capsule. The results obtained were satisfactory.
Jinpeng Liu, Harald Horn, Michael Wagner
· 2020
<p>Carbon-based and stainless steel-based materials are widely utilized as anode/cathode electrodes in bio electrochemical systems (BESs) due to its low capital cost, high conductivity and large specific surface area. Carbon-based materials such as carbon veil are mostly applied in lab-scale reactors because of its versatile shape and configuration. Moreover, stainless steel type materials show higher strength and are easier to incorporate within flow field. Optical coherence tomography (OCT) as an image technique is a suitable method to monitor biofilm growth and fluid-structure interactions at the meso-scale. In BESs, investigating bulk-biofilm interface (fluid-structure interactions) is of particular interest to optimize the mass transfer under suitable hydrodynamic condition and enhances the overall effectivity of BESs systems. To extend the knowledge about the influence of different anode electrodes as substratum on OCT monitoring and quantification, the biofilm structural properties analyzed by OCT image processing and bioelectrochemical systems performance were compared.  </p> <p>A custom-designed dual-chamber setup was constructed by two transparent optical flow cells and fixed in the automated monitoring platform (Evobot). Herein, we applied OCT to in-situ characterize and quantify the biofilm structure properties on two different anode electrodes (carbon veil-CV and porous stainless steel-SS) as substratum in microbial fuel cell (MFC) mode.  3D OCT dataset analysis presented 3 structural parameters for biofilm-carbon veil interface and 5 structural parameters for biofilm-stainless steel interface, separately. Biofilm volume (BioV) was calculated to compare CV and SS anode electrodes.</p> <p>In this study, a time-series of biofilm development was performed on both CV and SS materials. At the fourth day, the biofilm almost covered the entire anode surface and achieved 97% substratum coverage. Afterwards the biofilm grew mostly in vertical direction. With the further biofilm growth along height the electric resistance increased and power production gradually reached the equilibrium. Nevertheless, both materials did not show predominant advantage on power production. Furthermore, a relatively small error appeared on quantitative analysis of Biofilm volume using stainless steel. Whereas, the predictability of biofilm volume on the carbon veil anodes was hindered by the appearance of shadowing effects. Thus, it can be concluded that stainless steel flat plate electrode is preferable as anode material to investigate the interaction between biofilm structure, hydrodynamic conditions and mass transfer in BESs via OCT.</p>
Chonghui Yang
BIO Web of Conferences · 2023
Solar energy is the most abundant and clean energy on the earth, and developing equipment or devices with high-efficiency solar energy conversion is an effective way to alleviate the energy crisis. The majority of redox enzymes require a coenzyme to provide the hydrogen source needed for the reaction process, and the most commonly used coenzyme is nicotinamide adenine dinucleotide (NADH). However, NADH is expensive and easily decomposed, which greatly limits its application of artificial photosynthetic systems. We review recent progress in the construction of artificial photosynthetic systems that mimic natural photosynthesis.
Montadher M. Maktuf, Raed R. Shwaish, Shukry H. Aghdeab
BIO Web of Conferences · 2024
This study examined the material removal rate (MRR) affected by the variables of the electrochemical process including electrode type, voltage, electrolyte type, electrolyte concentration, and gap. Titanium alloy was employed as the workpiece, while copper was utilized as the cylindrical electrode. The input parameters were established according to Taguchi’s methodology. An analysis of variance (ANOVA) using a linear regression model was dependent on making sense of the experiment’s findings. the solid electrode achieved the maximum material removal rate (MRR) value (0.0857) g/min, while the hollow electrode with (1500 l/hour) flow rate achieved the minimum material removal rate (MRR) value (0.00002) g/min. the material removal rate (MRR) was directly proportional to the voltage. Maximum material removal rate (MRR) occurred at a concentration of (75 g/l) for the (NH 4 C) electrolyte, while minimum material removal rate (MRR) occurred at a concentration of (50 g/l) for the (NH 4 Cl) electrolyte. It has been observed that the contributing factors in controlling material removal rate (MRR) were as follows; (66.67%) for the voltage, (5.89%) for the electrode, (5.72%) for the electrolyte concentration, (3.24%) for the type of electrolyte, and (3.07%) for the gap.
Honglan Qi, Chengxiao Zhang
Luminescence · 2004
Abstract The electrogenerated chemiluminescence (ECL) reaction of lucigenin with isatin was investigated at a platinum electrode in a neutral aqueous solution. The ECL intensity of lucigenin at −0.65 V was greatly enhanced by isatin, and the ECL intensity was about 50 times higher than that of lucigenin without isatin. The enhanced ECL was believed to be produced by the chemiluminescence reaction between reduced lucigenin and superoxide anion that was generated by the reaction of electrochemically reduced isatin with dissolved oxygen. The conditions for the determination of isatin were optimized. Under the optimized condition, the enhanced ECL intensity vs. isatin concentration was linear in the range 4.8 × 10 −7 −1.9 × 10 −5 g/mL; with a detection limit of 3.3 × 10 −8 g/mL, and the relative standard derivation 1.0 × 10 −6 g/mL isatin was 3.8%. Copyright © 2004 John Wiley & Sons, Ltd.
Yin Song, Chunlei Wang
ECS Meeting Abstracts · 2014
There is urgent need to develop highly selective, sensitive and reproducible miniaturized bio-sensing platform based on reliable interface that is compatible with microfabrication processing. Our research objective is to advance fundamental research by fabricating pyrolyzed carbon arrays with high surface area as a bio-sensing electrode, developing the functionalization methods to increasing biomolecules immobilization efficiency and further understanding electrochemical phenomena occurring at bio/carbon interfaces. The carbon microelectrode arrays with high aspect ratio and porous surface have been fabricated by carbon microelectromechanical systems (C-MEMS) while the nanomaterials such as graphene have been integrated to further increase surface area. To achieve the efficient covalent immobilization of biomolecules, various oxidation and reduction functionalization methods have been investigated. The oxidation treatment we used in this study includes vacuum ultraviolet, electrochemical activation, UV/Ozone and oxygen RIE. The reduction treatment includes direct amination and diazonium grafting. The functionalized surface has been characterized using XPS, CV and FTIR to confirm and calculate the surface coverage of different functional groups. The developed bio-sensing platform was then applied for several applications, such as: DNA sensor; Glucose sensor; H 2 O 2 sensor; Aptamer sensor and HIV sensor. The performance and sensitivity of each biosensor will be discussed in the talk.
Qian Xiao
BIO Web of Conferences · 2023
With the aging of the population in China in recent years, the number of stroke patients is increasing day by day. The sequelae of stroke-induced foot drop are expected to regain some mobility after timely rehabilitation, but if patients do not receive early intervention, they may miss the best rehabilitation period and lose the ability to walk and stand completely. The traditional means of rehabilitation treatment is manual rehabilitation by rehabilitation physicians, but with the increase in the number of patients with movement disorders, the number of rehabilitation physicians has become significantly insufficient. The use of rehabilitation robots to provide adjunctive therapy to patients has become a common and effective means of rehabilitation worldwide. The early rehabilitation robots could only drive the patient to do passive rehabilitation and could not reflect the patient’s true motor intentions. Since EMG signals on the surface of the human body can advance the onset of human movement, they can be used to identify the intention of human movement. This paper validates and explores the experiment based on the underlying data.
Feng Li, Hua Cui, Xiang‐Qin Lin
Luminescence · 2002
Abstract The electrogenerated chemiluminescence of Ru(bpy) 3 2+ /C 2 O 4 2− system on a pre‐polarized Au electrode was studied using a potential‐resolved electrochemiluminescence (PRECL) method. Two anodic ECL peaks were observed at 1.22 V (vs. SCE) (EP1), 1.41 V (vs. SCE) (EP2), respectively. The effects of the concentration of oxalate and Ru(bpy) 3 2+ , adsorbed sulphur, CO 2 , O 2 , pH of the solution and pretreatment of the Au electrode on the two PRECL peaks were examined. The surface state of the pre‐oxidized gold electrode was also studied using the X‐ray photoelectron spectroscopy (XPS) technique. Moreover, comparative studies on i–E and I–E curves were carried out and a possible mechanism involving both the catalytic and the direct electro‐oxidation pathways was proposed for the ECL of Ru(bpy) 3 2+ /C 2 O 4 2− system. EP1 is attributed to the Ru(bpy) 3 2/3+ reaction catalysed by C 2 O 4 2− to generate Ru(bpy) 3 2+* . EP2 is likely because C 2 O 4 2− was oxidized at the electrode to form CO 2 −· , followed by reaction with Ru(bpy) 3 3+ to generate Ru(bpy) 3 2+* . Copyright © 2002 John Wiley & Sons, Ltd.
Ola G. Hussein, Yasmin Rostom, Amr M. Mahmoud et al.
Current Analytical Chemistry · 2025
Background: Traditional analysis techniques usually involve separation and pre-treatment steps prior to analysis, resulting in time and solvent consumption. In contrast, a potentiometric ion selective electrode is a simple, environmentally friendly, and cost-effective technique that is used as an alternative analytical technique, utilizing the efficacy of potentiometric sensors used in stability research and quality control investigations. Methods: An innovative Antazoline selective membrane sensor was constructed and evaluated to detect Antazoline in its pure form, eye drop formulations, degradation products, and biological fluid. Sensor fabrication was achieved using potassium tetrakis borate and polyvinyl chloride polymeric matrix plasticized with 2-nitrophenyl octyl ether and using calix[8]arene (CX8) as an ionophore. A comparative potentiometric study was implemented using two sensors, one using an ionophore and the other lacking the ionophore. Results: Linear responses of Antazoline were obtained utilizing sensors 1 and 2 in concentration ranges of 1.0×10-2 to 1.0×10-7 mole/L and 1.0×10-2 to 1.0×10-6 mole/L, correspondingly. Nernstian slopes of 58.486 and 51.2 mV/decade over pH 8.0 were attainted using 1 and 2 sensors, respectively. Conclusion: The proposed method was applied to determine antazoline without any need for any pretreatment or separation steps in both formulated eye drops Trillerg® sterile ophthalmic solution and Otrivine- Antistin® Eye Drops as well as in rabbit aqueous humor and the presence of its degradation products. Estimation of the method's greenness was confirmed using several assessment tools.
Shumin Liu, Jia Chen, Jinpeng Sun
Frontiers in Computing and Intelligent Systems · 2023
According to the good conductivity and electrocatalytic activity of multi-walled carbon nanotubes (MWCNTs) and the hydrogel properties of polyvinyl alcohol (PVA), MWCNTs and PVA double-network porous hydrogels were designed. MWCNTs/ PVA conductive hydrogels were prepared by electrophoretic deposition (EPD) and freeze-thaw cyclic crosslinking process. The electrochemical performance and microstructure of MWCNTs/PVA electrode film showed that MWCNTs/PVA hydrogel electrode film has a highly hydrophilic porous conducting hydrogel network structure. Although MWCNTs/PVA hydrogel electrode film has no obvious catalytic activity on glucose in PBS solution. However, it has obvious catalytic activity on dopamine and ascorbic acid.
Abbas Hassan Oghli, Esmaeel Alipour, Mojtaba Asadzadeh
RSC Advances · 2015
We developed a simple and reliable sensor for the determination of methamphetamine without expensive and time-consuming pretreatments using PPGE.
Ivan Sekerka, Josef F Lechner
Journal of AOAC INTERNATIONAL · 1978
Abstract The chloride ion selective electrode is used for a rapid, simple, and reliable determination of chloride ion in biological materials (blood serum, urine, fish, and plant tissues), food products (milk, beef extract, nutrient broth and orange, tomato, and grapefruit juices), soils, and waste water (industrial and municipal). The method consists of treating the samples with perchloric acid (pH 1) and potassium peroxydisulfate and determining the chloride content either by a calibration curve or by known addition or analyte addition, using the chloride ion selective electrode. Such sample treatment eliminates most of the interferences occurring in the samples, including iodide, complexing and reducing compounds, and macromolecular and surface-active species. The method is suitable for a wide range of chloride concentration, e.g., 5010 ppm CI in nutrient broth and 4890 ppm in beef extract and as low as 12 and 80 ppm in soil extracts.
Letters in Applied NanoBioScience · 2024
The possibility of the electrochemical determination of poisonous mushroom toxins psilocin and coprine on CoO(OH)-modified electrode has been evaluated theoretically. The analysis of the correspondent mathematical model confirms the efficiency of the electrochemical sensor for detecting both mycotoxins in mushrooms and biological liquids for either investigation or diagnostic purposes. The linear dependence between the concentration of both of the analytes is established in a wide concentration range, providing an excellent analytical signal interpretation.
Siriwan Nantaphol
· 2016
In this dissertation, analytical method/devices based on electrochemical detection are described for determining the important compounds/biomarkers in pharmaceutical and medical diagnostic applications, which can be separated into five parts. In the first part, electrochemical method for N-acetyl-L-cysteine (NAC) detection in drug formulations was developed using boron doped diamond (BDD) sensor coupled with flow injection analysis (FIA) system. The proposed method offers a linear range of 0.5 − 50 µmol/L, a limit of detection (LOD) of 10 nM, excellent response precision, and high stability. In the second part, an electrochemical cholesterol sensor was developed using silver nanoparticles modified glassy carbon electrode (AgNPs/GCE). Hydrogen peroxide (H2O2) produced from the enzymatic reaction was monitored for indirect cholesterol quantification. AgNPs showed the catalytic activity of H2O2 reduction, with no observed interference from easily oxidizable species. The proposed method displayed wide linear range of 3.87 - 773.40 mg/dL with LOD of 0.99 mg/dL. In the third part, a selective non-enzymatic glucose sensor was successfully developed using bimetallic Pt/Au modified BDD electrode. Pt/Au nanocatalyts possess high electrocatalytic activity for glucose oxidation in physiological conditions. A linear range of 0.01 -7.5 mM and a LOD of 0.01 mM were obtained. In the fourth part, a silver nanoparticle-modified boron-doped diamond (AgNP/BDD) electrode coupled with paper-based analytical devices (PADs) was developed for cholesterol detection. Cholesterol and cholesterol oxidase (ChOx) were directly drop-casted onto the hydrophilic area of PAD followed by monitoring of H2O2 from the enzymatic reaction using chronoamperometry. A linear range and a LOD were obtained at 0.01 - 7 mM and 6.5 uM, respectively. In the final part, the disposable boron doped diamond paste electrodes (BDDPEs) for microfluidic paper-based analytical devices (µPADs) were developed and employed for two applications; the quantitative detection of norepinephrine (NE) and serotonin (5-hydroxytryptamine, 5-HT), and the anodic stripping voltammetry of heavy metals. In case of biological species, the electrochemical paper-based analytical device (ePAD) was capable of simultaneously detecting NE and 5-HT in concentration ranges of 2.5−100 µM and 0.5−7.5 µM, respectively. For heavy metal quantitation, a flow-through µPAD design using square-wave anodic stripping voltammetry (SWASV) to enhance the efficiency of metal deposition was presented, thereby improving the detection sensitivity compared to a static ePAD system. The results demonstrated that all proposed method/sensors provide high sensitivity, selectivity, low cost, and portability.
J. Plegaria, M. Yates, Sarah M. Glaven et al.
ACS Applied Bio Materials · 2019
Bacterial microcompartment (BMC) shells are modular, selectively permeable, nanoscale protein shells that self-assemble from hexagonal and pentagonal building blocks in vivo or in vitro. Natural and engineered BMC shells colocalize and concentrate catalysts and metabolites in their lumen, increasing reaction kinetics. Here, we describe the design and characterization of a shell protein (pseudohexameric/trimeric BMC-T1HO protein) engineered to coordinate a Cu ion in its pore. Several designs, each varying the position of an introduced coordinating histidine residue, were shown to maintain their trimeric oligomerization state upon Cu coordination via chemical denaturation experiments. We measured reversible redox activity from electrode-bound Cu-3His BMC-T1HO variants, with formal potential(s) that were dependent on the Cu coordination site within the discoidal shaped trimer (E°' = +208 to +265 mV vs SHE). These results represent important steps toward expanding the functionality (Cu coordination) and applicability (redox activity on an electrode surface) of engineered BMC reactor architectures.
Mary P. Chang
Oxford Medicine Online · 2016
Bacterial meningitis is a bacterial infection causing inflammation of the meninges, the lining around the brain and spinal cord. It is important for emergency physicians to recognize potential bacterial meningitis early. They are usually the providers that the patient will present to first. If the patient is critically ill and suspicion for meningitis is high, immediately give steroids followed by antibiotics and then pursue diagnostic workup. Lumbar puncture will aid in definitive diagnosis. If this procedure will be delayed and suspicion for bacterial meningitis is high, give dexamethasone followed by antibiotics, even in a currently stable patient. Meningitis is a treatable condition, and early intervention will have a great impact on reducing morbidity and mortality.
Ha Thanh Dong
· 2015
Columnaris disease, a bacterial infection caused by Flavobacterium columnare, has been reported in various freshwater fish species worldwide. Disease outbreaks usually result in mass mortality of cultured fish and severe financial losses for aquaculture producers. In aquaculture system, where the fish naturally exposed to various potential pathogens, the reality of dead-loss due to dual or multiple infections is highly predictable and probably outweighs single infection. This study aims to investigate concurrent bacterial infections and pathogen characterization from columnaris diseased fish with emphasis on tilapia and striped catfish. From two outbreaks in Nile tilapia farms in Thailand where fish exhibiting external clinical signs of columnaris disease, each naturally diseased fish was found to be concurrently infected by 2 to 4 out of the 5 identified pathogens including F. columnare, Aeromonas veronii, Streptococcus agalactiae, Plesiomonas shigeloides and Vibrio cholera. Upon experimental challenge tests, fish exposed to A. veronii or F. columnare mimicked major internal and external clinical signs of naturally infected fish, respectively. This suggested that A. veronii and F. columnare are two main pathogens co-responsible for the dead-loss of the outbreak cases reported in the present study, whereas remaining pathogens might serve as opportunistic agents in the disease outbreaks. Similarly, natural co-infections of F. columnare and Edwardsiella ictaluri were first reported in the striped catfish exhibiting external clinical signs of columnaris disease. Co-infection challenge by both intraperitoneal and intramuscular routes successfully mimicked typical signs and histopathological manifestations of natural co-infections thus fulfilling Koch’s postulates. Genetic diversity of F. columnare revealed that isolates originated from tilapia and striped catfish were phylogenetically different based on 16S rRNA. It was also found that the majority of F. columnare isolates from Thailand belongs to Genomovar II and formed rhizoid morphotype on AOA medium. The virulence of two morphotypes (rhizoid and non-rhizoid colonies) of F. columnare from tilapia collection was determined in vivo. The typical rhizoid isolate (CUVET1214) was a highly virulent isolate whereas the non-rhizoid isolate (CUVET1201) was avirulent to red tilapia fry. Adherence and persistence of both F. columnare morphotypes to tilapia fry were determined by whole fish bacterial loads. The results suggested that an inability of the non-rhizoid morphotype to persist in tilapia fry may explain lack of virulence. Additionally, diversity of non-F. columnare bacteria associated with columnaris diseased fish was characterized and proven to be merely opportunistic bacteria in this study.
Peter Atkins, Julio de Paula, James Keeler
Atkins’ Physical Chemistry · 2022
This chapter discusses electrode potentials. Each electrode can be considered to make a characteristic contribution to the overall cell potential. The standard potential of a couple is the potential of a cell in which the couple forms the right-hand electrode and the left-hand electrode is a standard hydrogen electrode, all species being present at unit activity. The electrochemical series lists the metallic elements in the order of their reducing power as measured by their standard potentials in aqueous solution: low reduces high. The chapter then explains how the difference of the cell potential from its standard value is used to measure the activity coefficient of ions in solution. Meanwhile, standard potentials are used to calculate the standard cell potential and then to calculate the equilibrium constant of the cell reaction.
A. C. Fisher
Electrode Dynamics · 1996
This chapter deals with the molecular identity of the species, particularly intermediates, that must be indirectly inferred. It discusses the employment of electrochemical studies in combination with spectroscopic measurements in order to provide more direct characterization. It also explains the additional information obtained from spectroelectrochemical measurements that open the door to the investigation of a wide range of complex surface and homogeneous processes occurring in electrochemical systems. The chapter highlights the structure characterization of the electrode surface, the identification of homogeneous phase molecules, and the study of species absorbed at the electrode/electrolyte interface. It cites the ideal characterization of electrode surfaces that requires information on atomic resolution.
Matthias Wessling
· 2020
Scale-up of flow-electrode capacitive deionization is hindered due to the reliance on thick brittle graphite current collectors. Inspired by developments of electrochemical technologies we present the use of flexible membrane electrode assemblies (MEA) to solve these limitations. We tested different carbon-fiber fabrics as current collectorsand laminated them successfully with ion-exchange membranes. The use of thinner ion-exchange membranes is now possible due to the reinforcement with the carbon fiber fabric.Desalination experiments reveal that a MEA setup can achieve salt transfer rates equal to standard setups. Hence, we deduce that charge percolation also acts outside the electric field. In a single point of contact, ionic and electric charges are exchanged at the carbon surface of the MEA. The use of thinner membranes leads to a reduced potential drop. Together with a more homogeneous electric field across the feed water section, this can compensate for the reduction of contact surface between flow electrode and current collector.
Gerasymchuk, Y., Adamenko, O., Lavrishchev, A. et al.
Mehanization and electrification of agricultural · 2019
Purpose. Get dependence to determine the mass of the chemical adsorbent which is contained on the rotating precipitating electrode of the electrotechnical means, taking into account the kinetics of the process of air purification of livestock buildings from harmful gases and bacterial contamination with the complex use of electrophysical and chemical methods of decontamination and air purification. Methods. Analysis of the influence of chemical adsorbent and crown discharge field on the efficiency of air purification of livestock buildings from harmful gases and bacterial contamination. Experimental researches for determination of basic parameters of a precipitating electrode of an electrotechnical means. Results. Scheme of the electrotechnical means with the complex using of electrophysical and chemical methods of purification and disinfection of recirculation air of ventilation emissions from ammonia, carbon dioxide, hydrogen sulfide and bacterial contamination. Polynomial dependence for determining the mass of a chemical adsorbent which is contained on a rotating depositing electrode. Conclusions. Complex using of the electrotechnical means for air purification from harmful gases and bacterial contamination of the recirculation air flow and the utilization heat of ventilation emissions with the implementation anti-icing protection heat exchange surface of the recuperative heat utilizers allows to reduce the level of air exchange and significantly reduce energy costs to provide regulatory airspace of livestock buildings in the cold season. On the disks of precipitating electrodes of an electrotechnical mean for cleaning and disinfection of recirculation air of ventilation emissions, it is necessary to fix a polymer mesh with an area of cellules of 16 mm2, and the frequency rotation of the discs to support within the range from 0.25 s-1 to 1 s-1. Keywords: microclimate, heat utilizer, recuperate, air purification, corona discharge, precipitating electrode.
Jiaqi Lin, Dongyang Wang, Hailing Xue et al.
Research Square · 2024
Abstract Non-invasive brain-computer interfaces (NI-BCIs) have garnered significant attention due to their safety and wide range of applications. However, developing non-invasive electroencephalogram (EEG) electrodes that are highly sensitive, comfortable to wear, and reusable has been challenging due to the limitations of conventional electrodes. Here, we introduce a simple method for fabricating semi-dry hydrogel EEG sensors with antibacterial properties, enabling long-term, repeatable acquisition of EEG. By utilizing N-acryloyl glycinamide and hydroxypropyltrimethyl ammonium chloride chitosan, we have prepared electrodes that not only possess good mechanical properties (compression modulus 65 kPa) and anti-fatigue properties but also exhibit superior antibacterial properties. These electrodes effectively inhibit the growth of both Gram-negative ( E. coli ) and Gram-positive ( S. epidermidis ) bacteria. Furthermore, the hydrogel maintains stable water retention properties, resulting in an average contact impedance of less than 400 Ω measured over 12 hours, and an ionic conductivity of 0.39 mS/cm. Cytotoxicity and skin irritation tests have confirmed the high biocompatibility of the hydrogel electrodes. In N170 event-related potential (ERP) tests conducted on human volunteers, we successfully captured the expected ERP signal waveform, comparable to that of traditional wet electrodes. Moreover, contact impedance on the scalps remained below 100 kΩ for 12 hours, while wet electrodes became unable to detect signals after 7–8 hours due to dehydration. In summary, our hydrogel electrodes are capable of detecting ERPs over extended periods in an easy-to-use manner with antibacterial properties. This reduces the risk of bacterial infections associated with prolonged reuse and expands the potential of NI-BCIs in daily life.
O H Tuovinen, D J Nicholas
Applied and Environmental Microbiology · 1977
A commercially available ion-selective electrode for nitrate was used to continuously monitor tetrathionate oxidation by Thiobacillus dentrificans. The electrode was much more sensitive to tetrathionate than to nitrate. The same electrode could also be used for the determination of trithionate.
Yunlong Liu, Panpan Liu, Mengjuan Li et al.
Research Square · 2025
Abstract A bacterial molecularly imprinted bipolar electrode (BPE) sensor combined with Au@metal-organic frame (Au@MOF) was developed for the E. coli O157:H7 detection. Firstly, dopamine (DA) was mixed with E. coli O157:H7 through an electropolymerization process to form polymer film on the BPE cathode. After bacteria removal, the bacterial molecularly imprinted polydopamine (PDA) film remained on the cathode, exhibiting high specificity for bacterial recognition and binding. Secondly, the E. coli O157:H7 aptamer was modified to the Au@MOF surface by Au-SH covalent bonds. Then, E. coli O157:H7 was present at the cathode, through the specific binding of aptamer to E. coli O157:H7, Au@MOF was assembled to the electrode surface. Finally, 3,3′,5,5′-tetramethylbenzidine/H2O2 (TMB/H2O2) solution was added to the cathode. The Au@MOF exhibited peroxidase-like activity and could catalyze the reduction reaction of TMB/H2O2 system. Due to the electrical neutrality principle of the BPE, the oxidation reaction of [Ru(bpy)3]2+/tripropylamine ([Ru(bpy)3]2+/TPA) system on the anode, generating a distinct Electrochemiluminescence (ECL) signal. The sensor detected E. coli O157:H7 within a concentration range of 1 to 106 CFU mL-1, with a detection limit of 1 CFU mL-1, demonstrating high selectivity and sensitivity. This BPE platform, integrating molecular imprinting and Au@MOF-assisted oxygen reduction, shows significant potential for bacteria detection in various applications.
Masaya Nohara, Yuhki Yui, Shuhei Sakamoto et al.
ECS Meeting Abstracts · 2016
Introduction Lithium air secondary batteries exhibit higher theoretical energy density than lithium ion batteries and are expected as next-generation secondary batteries. However, there remain technical challenges related to their poor cycle properties. Since the first report by K. M. Abraham et al. [1], various oxygen reduction/evolution catalyst [1-3] and electrolyte [1, 4] materials have been intensively investigated for air batteries to improve their electrochemical properties, such as their cyclability. However, there have only been a few studies on support materials for air electrodes, such as nanoporous gold [5]. We consider that one of the reasons for the poor cyclability is a decrease in the electrical contact of the air electrode during Li 2 O 2 deposition (discharge) and oxygen generation (charge), which results from large the volume change. The purpose of our work is to improve the cyclability by using a new air electrode structure and material. As an elastic support material for air electrodes, we focus on carbon fabricated from bacterial cellulose (BC), which has a continuous interconnected network of carbon. Such an elastic carbon support would prevent the large volume change of the air electrodes and improve the cycle performance. Here we report the preparation conditions for BC-derived carbon supports materials and the performance of lithium air secondary batteries incorporating them. Experimental A BC sheet (Fujicco Co., Ltd.) was frozen at -40 °C and then freeze-dried [6]. The freeze-dried BC sheet was carbonized in N 2 atmosphere at 600, 900, and 1200 °C to obtain BC-derived carbon. It was cut into a circle (diameter: 5 mm) to obtain the binder-free air electrode. The lithium air secondary battery consisted of the air electrode, a lithium metal sheet, and 1.0 mol/l lithium bis(trifluoromethanesulfonyl)amide (LiTFSA)/tetraethylen glycol dimethyl ether (TEGDME) as the positive electrode, negative electrode, and electrolyte solution, respectively. The battery was assembled with an ECC-Air Cell (EL-CELL GmbH). Electrochemical measurements were carried out under a galvanostatic condition of 0.1 mA/cm 2 in an O 2 atmosphere. The discharge and charge capacities were normalized by the weight of the BC-derived carbon (the air electrode). Results and discussion Figure 1 shows an SEM image of the BC-derived carbon prepared at 1200 °C. The continuous interconnected network of the carbon fibers with diameter of less than 10 nm can be seen in this image. These carbon fibers build a 3-D disordered macroporous framework. The BC-derived carbon prepared at 600 and 900 °C was confirmed to have morphologies similar to that at 1200 °C. Moreover, in a preliminary compression test, the BC-derived carbon showed a highly elastic compressibility and almost completely recovered its original volume after the compression was released. Figure 2 shows the first discharge/charge curves of the air batteries incorporating the BC-derived carbon prepared at 600, 900, and 1200 °C. The air batteries with the carbon prepared at 900 °C showed the largest discharge capacities of 8800 mAh/g and the average discharge voltage of 2.68 V. This is because it has the largest number of active sites among the carbons tested. The batteries incorporating BC-derived carbon prepared at 900 and 1200 °C showed almost the same charge capacities of about 8000 mAh/g. These charge properties have a tendency similar to the discharge properties even though the air electrodes have no catalysts. These results indicate that the BC-derived carbon can be used as support material for binder-free air electrodes. Figure 3 shows the correlation between the discharge capacities, D/G ratio, and carbonization temperature. In the Raman spectra of the carbon as shown in the inset, the peaks of D- and G-bands are derived from the edge-plane and basal-plane in the crystal structure of carbon, respectively. The D/G ratio was obtained from the results of wave analyses with the spectra in the inset. It correlates roughly with the discharge capacities as shown in Fig. 3. In particular, the battery incorporating the carbon prepared at 900 °C, which has the largest discharge capacity, has the highest D/G ratio. This indicates the importance of the number of carbon edge planes in relation to the discharge property, because the D/G ratio corresponds to a ratio of number of carbon edge planes to that of basal planes. These results indicate that the carbon edge planes would play an important role as active sites in the reaction mechanism with the air electrode. References [1] K. M. Abraham et al., J. Electrochem. Soc., 143 (1996) 1. [2] T. Ogasawara et al., J. Am. Chem. Soc., 128 (2006) 1390. [3] A. K. Thapa et al., Electrochem. Solid-State Lett., 13 (2010) A165. [4] N.-S. Choi et al., J. Power Sources, 225 (2013) 95. [5] Z. Peng et al., Science, 375 (2012) 563. [6] H. W. Liang et al., NPG Asia Materials, 4 (2012) e19. Figure 1