Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
Carolin Psotta
· 2023
This thesis is focused on developing electrochemical (bio-)sensors specifically designed to detect biomolecules and bacteria in human physiological fluids. A more comprehensive understanding of their performance can be obtained by exposing the sensors to real human physiological fluids. Thus, four biosensors were designed and tested in saliva, plasma, blood, and urine. Specifically, a voltammetric electronic tongue, integrating six different electrode materials, was developed to qualitatively assess SARS-CoV-2 in saliva samples using principal component analysis. A tubular enzyme-based sensor utilizing incorporated cellobiose dehydrogenase in an Os(bpy)PVI redox polymer was employed for continuous glucose sensing in human plasma and undiluted whole blood under homeostatic conditions. Two different sensing concepts were developed for the label-free detection of bacteria (Escherichia coli, Enterococcus faecalis, and Klebsiella pneumoniae) in artificial urine and human urine based on metabolic activity due to bacterial growth. The first sensor enabled continuous bacterial detection by reducing Prussian Blue deposited on screen-printed electrodes with wireless data transfer. The second bacterial-sensitive sensor utilized electrochemical characterization to identify three bacteria types based on artificial urine metabolic changes. For a qualitative investigation of the metabolic changes, nuclear magnetic resonance was utilized, and flow cytometry was used to quantify and correlate bacterial growth with electrochemistry. Multivariate statistical data analysis was applied to distinguish bacteria-free and bacteria-infected artificial urine. Finally, an overview of the recent advances in the field of non-invasive electrochemical biosensors operating in secreted human physiological fluids, viz., tears, sweat, saliva, and urine, was give
Yair Farber, David Rasuli, Yaniv Shlosberg
bioRxiv (Cold Spring Harbor Laboratory) · 2024
Abstract The world is striving for the development of novel clean energy technologies that can replace the utilization of fossil fuels, and assist in the struggle against climate change. A unique approach that does not involve any carbon emission is bio-photo electrochemical cells (BPECs). This method integrates live organisms with an electrochemical system, while native redox species that exist in the organisms can generate dark and photo electrical current. Such systems were previously shown using photosynthetic micro and macro organisms in which the photocurrent mostly derives from photosynthesis. Another electron source was reported to originate from cherries which consist of pigments and enhance the production of the strong electron donor ascorbic acid under solar irradiation. In this work, we show the ability to produce electrical and photoelectrical current from beet juice. We apply cyclic voltammetry and fluorescence methods to show that among the major components that play a role in the current and photocurrent generation are NADPH and flavins.
Yifan Dai, C. Liu
Angewandte Chemie International Edition · 2019
A number of very recently developed electrochemical biosensing strategies are promoting electrochemical biosensing systems into practical point-of-care applications. Focus of research endeavors in biosensing community has transferred from detection of a specific analyte to the development of general biosensing strategies that can be applied for a single category of analytes, such as nucleic acid, protein and cell. In this review, we describe most recent cutting-edge researches on electrochemical biosensing strategies. These described developments resolved critical challenges on application of electrochemical biosensors to the practical point-of-care systems, such as rapid readout, simple biosensor fabrication method, ultra-high detection sensitivity, direct analysis in complex biological matrix and multiplexed targets analysis. This review provides general guidelines both for scientists in the biosensing research community and for the biosensor industry on development of point-of-care system, benefiting global healthcare.
H. Felgueiras, L. Castanheira, S. Changotade et al.
Journal of Biomedical Materials Research Part B: Applied Biomaterials · 2015
The purpose of this study was to investigate the relationship between the osteoblastic cells behavior and biotribocorrosion phenomena on bioactive titanium (Ti). Ti substrates submitted to bioactive anodic oxidation and etching treatments were cultured up to 28 days with MG63 osteoblast-like cells. Important parameters of in vitro bone-like tissue formation were assessed. Although no major differences were observed between the surfaces topography (both rough) and wettability (both hydrophobic), a significant increase in cell attachment and differentiation was detected on the anodized substrates as product of favorable surface morphology and chemical composition. Alkaline phosphatase production has increased (≈20 nmol/min/mg of protein) on the anodized materials, while phosphate concentration has reached the double of the etched material and calcium production increased (over 20 µg/mL). The mechanical and biological stability of the anodic surfaces were also put to test through biotribocorrosion sliding solicitations, putting in evidence the resistance of the anodic layer and the cells capacity of regeneration after implant degradation. The Ti osteointegration abilities were also confirmed by the development of strong cell-biomaterial bonds at the interface, on both substrates. By combining the biological and mechanical results, the anodized Ti can be considered a viable option for dentistry.
Alexandra Bondarenko, F. Cortés-Salazar, M. Gheorghiu et al.
Analytical Chemistry · 2015
To understand biological processes at the cellular level, a general approach is to alter the cells' environment and to study their chemical responses. Herein, we present the implementation of an electrochemical push-pull probe, which combines a microfluidic system with a microelectrode, as a tool for locally altering the microenvironment of few adherent living cells by working in two different perturbation modes, namely electrochemical (i.e., electrochemical generation of a chemical effector compound) and microfluidic (i.e., infusion of a chemical effector compound from the pushing microchannel, while simultaneously aspirating it through the pulling channel, thereby focusing the flow between the channels). The effect of several parameters such as flow rate, working distance, and probe inclination angle on the affected area of adherently growing cells was investigated both theoretically and experimentally. As a proof of concept, localized fluorescent labeling and pH changes were purposely introduced to validate the probe as a tool for studying adherent cancer cells through the control over the chemical composition of the extracellular space with high spatiotemporal resolution. A very good agreement between experimental and simulated results showed that the electrochemical perturbation mode enables to affect precisely only a few living cells localized in a high-density cell culture.
S. Kuss, D. Trinh, J. Mauzeroll
Analytical Chemistry · 2015
Scanning electrochemical microscopy (SECM) is increasingly applied to study and image live cells. Quantitative analyses of biological systems, however, still remain challenging. In the presented study, single human adenocarcinoma cervical cancer cells are electrochemically investigated by means of SECM. The target cell's electrochemical response is observed over time under the influence of green tea catechins (GTC), which are suggested to offer chemopreventive and therapeutic effects on cancer. The electrochemical response of living target cells is measured experimentally and quantified in an apparent heterogeneous rate constant by using a numerical model, based on forced convection during high speed SECM imaging. The beneficial effect of GTC on cancer cells could be confirmed by SECM, and the presented study shows an alternative approach toward unraveling the mechanisms involved during inhibition of carcinogenesis.
K. Hua, Igor Rocha, Peng Zhang et al.
Biomacromolecules · 2016
This work presents an insight into the relationship between cell response and physicochemical properties of Cladophora cellulose (CC) by investigating the effect of CC functional group density on the response of model cell lines. CC was carboxylated by electrochemical TEMPO-mediated oxidation. By varying the amount of charge passed through the electrolysis setup, CC materials with different degrees of oxidation were obtained. The effect of carboxyl group density on the material's physicochemical properties was investigated together with the response of human dermal fibroblasts (hDF) and human osteoblastic cells (Saos-2) to the carboxylated CC films. The introduction of carboxyl groups resulted in CC films with decreased specific surface area and smaller total pore volume compared with the unmodified CC (u-CC). While u-CC films presented a porous network of randomly oriented fibers, a compact and aligned fiber pattern was depicted for the carboxylated-CC films. The decrease in surface area and total pore volume, and the orientation and aggregation of the fibers tended to augment parallel to the increase in the carboxyl group density. hDF and Saos-2 cells presented poor cell adhesion and spreading on u-CC, which gradually increased for the carboxylated CC as the degree of oxidation increased. It was found that a threshold value in carboxyl group density needs be reached to obtain a carboxylated-CC film with cytocompatibility comparable to commercial tissue culture material. Hence, this study demonstrates that a normally bioinert nanomaterial can be rendered bioactive by carefully tuning the density of charged groups on the material surface, a finding that not only may contribute to the fundamental understanding of biointerface phenomena, but also to the development of bioinert/bioactive materials.
M. Ramuz, Adel Hama, Jonathan Rivnay et al.
Journal of Materials Chemistry B · 2015
Electrical, label-free monitoring of cells is a non-invasive method for dynamically assessing the integrity of cells for diagnostic purposes. The organic electrochemical transistor (OECT) is a device that has been demonstrated to be advantageous for interfacing with biological systems and had previously been shown to be capable of monitoring electrically tight, resistant, barrier type tissue. Herein, the OECT is demonstrated not only for monitoring of barrier tissue cells such as MDCK I, but also for other, non-barrier tissue adherent cells including HeLa cells and HEK epithelial cells. Transistor performance, expressed as transconductance (gm) is measured as a function of frequency; barrier tissue type cells are shown to have a more abrupt drop in transconductance compared to non-barrier tissue cells, however both tissue types are clearly distinguishable. Simple modelling of the cell layers on the transistor allows extraction of a resistance term (Rc). OECT monitoring shows that barrier tissue cells lose their barrier function in a standard calcium switch assay, but remain adhered to the surface. Re-addition of calcium results in recovery of barrier tissue function. The entire process is continuously followed both electronically and optically. Finally, high resolution fluorescence imaging of live cells labelled with a red fluorescent actin marker demonstrates the versatility of this method for tracking molecular events optically, with direct correlation to electronic readouts.
Rui Jia, S. Rotenberg, M. Mirkin
Analytical Chemistry · 2022
Extracellular vesicles (EVs) released from biological cells have attracted considerable interest due to their potential for cancer diagnostics and important role in cell signaling. Most previously reported studies have been concerned with the detection of EVs in biofluids and analysis of proteins and nucleic acids they contain. Electrochemical resistive-pulse (ERP) sensing enables direct detection of single EVs released from a specific cell and analysis of reactive oxygen and nitrogen species in such vesicles. Here, we demonstrate the applicability of ERP sensing to distinguish between nontransformed and cancerous breast cell lines as well as between breast cancer cell lines with different metastatic potential. Another application of ERP sensing is in real-time monitoring of changes in a single cell induced by a chemical agent. This approach is potentially useful for evaluating the efficacy of therapeutic agents, including those that trigger breast cancer cell death by inducing intense oxidative stress.
Jing Su, Shixing Chen, Yanzhi Dou et al.
Analytical Chemistry · 2022
Exosomes are potential biomarkers, which play an important role in early diagnosis and prognosis prediction of cancer-related diseases. Nevertheless, direct quantification of exosomes in biological fluid, especially in point-of-care tests (POCTs), remains extremely challenging. Herein, we developed a sensitive and portable electrochemical biosensor in combination with smartphones for quantitative analysis of exosomes. The improved double-antibody sandwich method-based poly-enzyme signal amplification was adopted to detect exosomes. We could detect as low as 7.23 ng of CD63-positive exosomes in 5 μL of serum within 2 h. Importantly, we demonstrated that the biosensor worked well with microliter-level serum and cell culture supernatant. The biosensor holds great potential for the detection of CD-63-expressing exosomes in early diagnosis of prostate disease because CD63-positive exosomes were less detected from the prostate patient serum. Also, the biosensor was used to monitor the secretion of exosomes with the drug therapy, showing a close relationship between the secretion of exosomes and the concentration of cisplatin. The biosensing platform provides a novel way toward POCT for the diagnosis and prognosis prediction of prostate disease and other diseases via biomarker expression levels of exosomes.
S. Shin, Tugba Kilic, Y. S. Zhang et al.
Advanced Science · 2017
Development of an efficient sensing platform capable of continual monitoring of biomarkers is needed to assess the functionality of the in vitro organoids and to evaluate their biological responses toward pharmaceutical compounds or chemical species over extended periods of time. Here, a novel label‐free microfluidic electrochemical (EC) biosensor with a unique built‐in on‐chip regeneration capability for continual measurement of cell‐secreted soluble biomarkers from an organoid culture in a fully automated manner without attenuating the sensor sensitivity is reported. The microfluidic EC biosensors are integrated with a human liver‐on‐a‐chip platform for continual monitoring of the metabolic activity of the organoids by measuring the levels of secreted biomarkers for up to 7 d, where the metabolic activity of the organoids is altered by a systemically applied drug. The variations in the biomarker levels are successfully measured by the microfluidic regenerative EC biosensors and agree well with cellular viability and enzyme‐linked immunosorbent assay analyses, validating the accuracy of the unique sensing platform. It is believed that this versatile and robust microfluidic EC biosensor that is capable of automated and continual detection of soluble biomarkers will find widespread use for long‐term monitoring of human organoids during drug toxicity studies or efficacy assessments of in vitro platforms.
Rongrong Pan, Dengchao Wang, Kang Liu et al.
Journal of the American Chemical Society · 2022
Measuring the activity of low-abundance enzymes, down to a few molecules in one living cell, is important but challenging to elucidate their biological function. Here, an electrochemical molecule trap is established at the tip of a nanopipette with an electrochemical detector, in which the diffusion of the molecules away from the electrochemical detector is prevented by electro-osmotic flow (EOF). Accordingly, a limited amount of enzymes is trapped to continuously catalyze the conversion of the substrate to generate a sufficient amount of the byproduct hydrogen peroxide for electrochemical measurements. The resistive pulse sensing of the enzymes in single liposomes validates the detection sensitivity down to 15 molecules. Using this ultrasensitive electrochemical strategy, the activity of 60 sphingomyelinase molecules inside single unstimulated living J774 cells is measured, which was hardly detected by previous methods. The established electrochemical molecule trap-based sensing approach opens the door toward single-molecule electrochemical detection in one living cell. This success will solve the long-standing problem regarding the study of the activity of low-abundance proteins in cells in their native physiological state and greatly enhance the understanding of the roles of proteins in cellular behavior.
Alina V. Geraskevich, A. N. Solomonenko, E. Dorozhko et al.
Critical Reviews in Analytical Chemistry · 2022
Abstract Reactive oxygen species (ROS) involving superoxide anion, hydrogen peroxide and hydroxyl radical play important role in human health. ROS are known to be the markers of oxidative stress associated with different pathologies including neurodegenerative and cardiovascular diseases, as well as cancer. Accordingly, ROS level detection in biological systems is an essential problem for biomedical and analytical research. Electrochemical methods seem to have promising prospects in ROS determination due to their high sensitivity, rapidity, and simple equipment. This review demonstrates application of modern electrochemical sensors for ROS detection in biological objects (e.g., cell lines and body fluids) over a decade between 2011 and 2021. Particular attention is paid to sensors materials and various types of modifiers for ROS selective detection. Moreover, the sensors comparative characteristics, their main advantages, disadvantages and their possibilities and limitations are discussed.
A. Hamnett
Handbook of Fuel Cells · 2010
Abstract Electrochemical cells are formed when two electronically conducting electrodes are placed in an ionically conducting medium, the electrolyte . When current is passed through the cell, electrochemical reactions take place at each electrode, leading to nett chemical conversion of one or more constituents of the cell into new materials. This chapter reviews the nature of the chemical reactions in simple cells, distinguishes between electrolysis and galvanic cell operation, describes the structure and dynamical behavior of the electrolyte, and reviews the properties of some special electrolytes of relevance to fuel cells: ionically conducting membranes, solid ionic conductors and molten salts.
Oliver Harris, Maureen H. Tang
· 2020
While the Li-ion battery has been engineered over the last four decades to improve energy capacity, power density, and device safety, the useful lifetime of this essential energy storage technology has not progressed as much. This is largely due to experimental challenges of studying, characterizing, and understanding the SEI: the battery `component' most vital to ageing and failure. More importantly for the goal of improving Li-ion battery lifetime, researchers have lacked adequate diagnostic tools for studying how the SEI fails. Here we demonstrate a prototype electrochemical flow cell for the specific application of detecting crosstalk reactions in advanced Li-ion battery chemistries. We develop a generator-collector approach to understanding battery crosstalk and leverage finite-element simulations to guide design of this novel reactor. After calibrating the device using a known redox couple, the device is cycled under varying electrode configurations to detect capacity fade induced by the metal dissolution crosstalk mechanism. The path forward will involve adding new product detection capabilities and engineering a reactor environment that replicates a sealed Li-ion battery.
A. S. Stikhin, V. I. Teslya, A. P. Tsedilkin et al.
Electrochemical Energetics · 2008
A 350–400 V storage battery is necessary as a buffer or auxiliary battery for electrically driven car with fuel cell power plant developed at UEIP together with «AvtoVAZ». With this aim in view, the development of batteries with filter-press configuration based on nickel metal hydride system is of great interest. Sequential assembly of cells that are in contact through separating metal plates in one casing permits to reduce the mass and dimensions characteristics during high-voltage battery manufacturing to a considerable extent in comparison with the batteries where cells are positioned in separate casings. The analysis of electrode group operating modes and design characteristics calculation of full-size nickel metal hydride battery with filter-press configuration was performed.
Firas A. Al-Lolage, Saiful Arifin Shafiee
Journal of Electrochemical Science and Technology · 2024
<p>Carbon materials, such as the boron-doped diamond (BDD), are commonly used in the field of electroanalytical sensors and chemical generators. This study focuses on using the scanning electrochemical microscopy (SECM) and the scanning electrochemical cell microscopy (SECCM) techniques for probing the surface heterogeneity of the carbon-based materials of interest. Three BDD electrodes with high concentrations of boron doping, were investigated in this study. The GC and HOPG electrodes were used as standards for their behaviour. The SECM results on the lowest doped BDD electrode (2.94×10<sup>20</sup> cm<sup>−3</sup>; 2000 ppm) in this study imply that the BDD electrode behaves similar to a gold substrate: The feedback kinetic rate constant, <italic>k</italic><italic><sub>feedback</sub></italic>, obtained, was 0.009–0.013 cm s<sup>−1</sup> (the gold substrate’s value: 0.014 cm s<sup>−1</sup>). The Raman spectra show that all the BDD electrodes exhibit metallic conductivity and also that the non-diamond carbon (NDC) cannot be removed from the BDD films. The presence of graphite, buckminsterfullerene, and fullerite were detected in the BDD films based on the X-Ray diffraction (XRD) spectra. A background current and a potential window study were performed, using the SECCM technique; the BDD electrode with the lowest boron doping shows the widest potential window among the electrodes of interest. This potential window decreases as the boron concentration increases. The results of the standard electrodes show that they share the same and narrowest potential windows among the carbon electrodes. The HOPG electrode has the smallest double layer capacitance while the GC electrode has a relatively large background current. As the boron concentration increases, the background currents for the BDD electrodes increase. The same carbon-based electrodes were also investigated in dissolved ferrocyanide using the SECCM technique. The results show that the GC electrode has the fastest kinetic transfer in comparison to the HOPG electrode. As the boron concentration increases, the kinetic transfer of the BDD electrodes increases.</p>
Khiena Z. Brainina, Liliya K. Shpigun
Electrochemical Science Advances · 2023
Abstract The present review focuses on the interplay between electrochemistry and life, events on the border of electrochemistry‐biology‐life science, electrochemistry as the basis, and the information source on oxidative stress (OS) or Red/Ox state of biological systems and food to be investigated. Electroanalytical chemistry provides rapid, relatively simple, and sensitive approaches to assess the redox characteristics and antioxidant activity of biologically active compounds in various samples. OS is a relatively new physiological response concept, recognized in medicine and biology in the last three decades. This phenomenon is caused by an imbalance between (pro)oxidants and antioxidants in living organisms and it is related to the fundamental redox reactions that underlie health signaling and life processes in general. OS can contribute to many pathological conditions and diseases. In particular, it is recognized that a highly contagious infectious disease, coronavirus disease 2019, is associated with an inflammation process related to OS‐induced cellular changes. Recent years have shown a marked increase in electrochemical studies of OS and quantitation of its reductant‐oxidant markers (signaling agents), such as reactive oxygen species and antioxidants. The goal of this overview is to cover the brief scope of modern electrochemical analysis and sensor devices for monitoring biomarkers of OS and antioxidant status of biological systems. By discussing the great potential of potentiometric and voltammetric methods for human health assessment, it is hoped to bridge between recent electrochemical research and medical diagnostic treatment in the 21st century.
Liju Yang
ECS Meeting Abstracts · 2015
As a principle of transduction, the impedance technique has been applied in the field of biological study ranging from microbiology to cancer cell/tissue studies. This paper summarizes the applications of electrical/electrochemical impedance spectroscopy that have been practiced in our research in the past several years, mainly including two distinct fields--the detection of foodborne bacterial pathogens and the study of oral cancer cells. Foodborne diseases caused by foodborne pathogens have been a serious threat to public health for decades and remain one of the major concerns of our society. The development of rapid, sensitive, and specific methods is central to implementing effective practice to ensure food safety and security. We have been using impedance technique as a means to detect and/or quantify foodborne pathogenic bacteria. This paper will particular introduce the recent significant development in this field, including the use of microfabricated microelectrodes, microfluidic chip-based devices, nanoparticles and integration with other techniques such as dielectrophoresis. Based on the fundamental impedance microbiology, which is a technique based on the measurement of changes in electrical impedance of a culture medium or a reaction solution resulting from the bacterial growth, we have added some new aspects to this subject that have made the impedance technique a more valuable technique for detection of foodborne bacterial pathogens. These aspects include the use of different electrode systems and the analysis of impedance components using equivalent circuits for better improvement on the detection systems. The advances in microfabrication technologies have launched the use of microfabricated microarray electrodes in impedance detection and the miniaturization of impedance microbiology into a chip format, which has shown great promising in rapid detection of bacterial growth. Further, the integration of impedance technique with biosensor technology has led to the development of impedance biosensors that is expending rapidly for bacteria detection in recent years. Impedance biosensors for bacteria detection are based on the analysis of electrical properties of bacterial cells when they are attached to or associated with the electrodes. Such impedance biosensor methods have substantially reduced the assay time down to 30 min~2 h compared with growth-based impedance methods. The dimensional compatibility of those microfabricated biosensors with the target bacterial cells has enabled them to detect the binding of bacterial cells on its surface without any amplification step. On the other hand, electrical impedance spectroscopy (EIS) enables direct sensing of cellular activities occurring on an electrode surface by measuring the induced capacitance and/or resistance changes by cells attached on the electrode. Particular, EIS is capable of distinguishing different types of cells based on the cellular activity-induced electrical signals. We have demonstrated the use of real-time impedance technique to study the cellular activities of oral cancer cells in a label-free manner, including cell proliferation, adhesion, spreading, and apoptosis induced by drug treatments. Furthermore, it is known that during transformation from non-cancer cells to caner cells, the cellular morphology, structure, and function are altered, which may includes, but are not limited to changes in the nuclei, composition of the cytoplasm, structure of the cell membrane, changes in the nuclei, composition of the cytoplasm, structure of the cell membrane, and expression levels of ion channels, etc. These changes may result in alterations in cancer cell properties that could be detected by the EIS well before these morphological features that normally used in detection can be seen or biomarkers are developed. We have explored the use of real-time impedance measurements to distinguish oral cancer cells from normal oral epithelial cells in label-free manner by studying the kinetics of cell spreading and attachment of the two cell types.
Ajyal Zaki Alsaleh
· 2019
Six peripherally meso-modified Zn (II) porphyrin sensitizer dyes are designed and their J-V performance in dye sensitized solar cell (DSSC) evaluated. Electron-donating groups including phenothiazine, carbazole and pyrene are used to modify the porphyrin macrocycle at the meso-carbon position(s). To compare the effect of donor substitution on the performance of the cells in terms of short circuit current (Jsc), light harvesting efficiency (LHE) and power conversion efficiency (η), two sets of sensitizers with different degrees of substitution are synthesized. One set of dyes (mono-substituted) have one electron donor at trans-position to the acceptor, while the second set (tri-substituted) dyes have three of the same type electron donor groups at 5, 10 and 15 meso-carbon positions making all the six dyes push-pull type sensitizers incorporating 4'-carboxyphenyl as an electron-acceptor/anchor group. Different spectroscopic and electrochemical methods are used to study the photophysical and electrochemical properties of the dyes, while the photovoltaic performance of their cells under 1.5 A.M is studied using solar simulator. Meso-substitution of Zinc (II) porphyrin with these small donor molecules is shown to improve the light harvesting character of the Zinc (II) porphyrin macrocycle in the UV-Vis absorption while at same time improving its fluorescence quantum yield, excited-state life time and electron donating potential. All these factors combined make these meso-modified dyes better sensitizers with suitable Δ0 Δ0, and much improved power conversion efficiencies (PCE) compared to unsubstituted Zn (II) porphyrin. In particular, as a result of the peripheral modification, a doubling in efficiency in the mono- substituted series (RA-200-Zn; η=^M 4.2%, Jsc= -13.13 mA cm-2, Voc=0.54 ) and tripling in the tri-substituted series ( tri-phenothiazine Zn (II) Porphyrin; η= 7.3%, Jsc= -18.15 mA cm-2, Voc= 0.55 ) compared to unsubstituted Zn (II) porphyrin (η= 2.11%, Jsc= -5.7 mA cm-2, Voc= 0.53 V) has been accomplished.
Hitoshi Shiku, Hiroaki Ohya, Tomokazu Matsue
Encyclopedia of Electrochemistry · 2002
Abstract The sections in this article are SECM Feedback Mode Generation/Collection Mode Applications to Biological Systems Enzymes Antigen–Antibodies Local Fluxes Through Biological Materials Liquid–Liquid Interfaces, Liquid–Air Interfaces Planar BLMs Cells, Tissues
Ghassan Hamad Abdulla
· 2017
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Crude oil contains natural organic components such as organosulfur compounds, and these compounds largely remain in refined petroleum products such as gasoline, diesel and jet fuel products. During fuel combustion, sulfur was emitted as sulfur dioxide or sulfate, which is one of the main causes of air pollution and acid rain. The oil price is inversely proportional to the sulfur content because upgrade of heavy, high-sulfur-containing oil is much more difficult than the light feeds. Many regulations have been established by different countries to control sulfur level in fuels; in the U.S. the maximum required concentration is 15 ppm (parts per million) sulfur in diesel. The most commonly used technology to remove sulfur from diesel fuel is hydrodesulfurization (HDS). The major drawback of HDS is the harsh operating conditions that require high temperatures and pressures with consumption of a large amount of hydrogen. The HDS process is only able to reduce sulfur content to about 500 ppm in diesel. Further reduction requires more intense processing with a significant increase in hydrogen usage, particularly in removing the refractory sulfur compounds, such as benzothiophene (BT), dibenzothiophene (DBT), and their alkyl derivatives. In this dissertation, an efficient and cost-effective process for oxidation of organosulfur compounds (OSCs) in diesel has been developed and investigated. A divided-cell trickle bed electrochemical reactor (TBER) was first developed to produce hydrogen peroxide. The divided-cell trickle bed electrochemical reactor (TBER) has a porous cathode composed of carbon black and polytetrafluoroethylene. It was designed and fabricated to have hydrophobic and hydrophilic components for liquid and gas flows. Hydrogen peroxide generation was successfully demonstrated from reducing oxygen in concentrated alkaline electrolyte solutions. An important feature of the reactor was a cathode made with stainless steel meshes that divide it into four packed-bed cells. This division into sectional cathode resulted in a concentration of hydrogen peroxide that more than doubles that produced in an undivided cathode. The much-improved performance was attributed to the even distribution of the electrolyte and oxygen in the cathode bed, as well as an effective mass transport of oxygen from the gas phase to the electrolyte-cathode interface. After the successful production of hydrogen peroxide, the TBER was employed for in situ oxidation desulfurization of diesel fuel. The possibility of diesel desulfurization with in situ generated hydrogen peroxide in the presence of DBT was systematically investigated. The maximum concentration of hydrogen peroxide after two-hour electrolysis was 31.79 mM without diesel, whereas in the presence of 10% diesel (by volume) in the electrolyte was 18.0 mM. DBT was successfully oxidized in situ in the TBER, with conversion efficiency of 97.75% in six hours. To further improve the efficiency of the hydrogen peroxide production, cathode was modified with MnO2, a potentially more active catalyst for hydrogen peroxide production in alkaline electrolytes. It was found that incorporation of MnO2 indeed promoted in situ oxidation of DBT which was attributed to more hydrogen peroxide produced. The results showed the in situ oxidation process in the divided-cell TBER is a promising and environmentally friendly approach for desulfurization of diesel.
Gomuraj Santhanaraj, Mathavan Alagarsamy, Chinnapaiyan vedhi
Research Square · 2024
Abstract Detection and monitoring of toxic and exhaust gases are crucial for energy and environmental conservation. Low-power, inexpensive gas sensors are in high demand. Metal oxide gas sensors are gaining interest due to their high selectivity and sensitivity. This research work aims to synthesize and characterize metal oxides, specifically thorium(IV) oxide, iron(III) oxide, and FTMMO, which is a mixed metal oxide consisting of iron and thorium. The synthesis of nanoparticles is accomplished using the co-precipitation method with a microwave reaction system. The resulting nanoparticles are subsequently characterized utilizing various analytical techniques such as FT-IR, UV-VIS (DRS), FE-SEM, EDAX, AFM, and XRD analysis. The cubic geometry of ThO2 and the face-centered rhombohedral structure of α-Fe2O3 nanoparticles were verified by XRD analysis. In order to investigate the utilization of iron(III) oxide, thorium(IV) oxide and iron thorium mixed metal oxides (FTMMO) are used to recognizes of ammonia and sulfur dioxide with the help of electrochemical method in the basic medium. The binding behavior of metal oxides and ovalbumin were investigated using UV-visible adsorption and fluorescence spectral techniques. The binding constant (Kb), Stern-Volmer constant (Ksv), and fluorophore quenching rate constant (kq) were calculated with the help of spectral data. Using the disc diffusion technique, research has been carried out to investigate the exceptional antibacterial activities of prepared metal oxides and mixed metal oxides against the different bacterial strains.
Sayed Zia Mohammadi, Farideh Mousazadeh
Journal of Electrochemical Science and Engineering · 2022
In the current study, a glassy carbon electrode (GCE) modified with graphene-CoS2 nanocomposite was investigated for electrochemical sensing of ascorbic acid. The electrochemical performance of the modified electrode was examined using differential pulse voltammetry (DPV), linear sweep voltammetry (LSV) and chronoamperometry (CHA) techniques. The electrochemical behavior of ascorbic acid at the graphene-CoS2/GCE displayed a higher oxidation current and lower oxidation potential than bare GCE. Under the optimal experimental conditions, the sensor presented a good linear response between the current and the ascorbic acid concentration range of 0.15–245.0 μM, with a low detection limit of 0.05 μM. Finally, the graphene-CoS2 nanocomposite-modified GCE was applied for the determination of ascorbic acid in real samples and displayed excellent recoveries.
Farzaneh Shaker, Mohammad Taghi Vardini, Moosa Es’haghi et al.
Rudarsko-geološko-naftni zbornik · 2022
Metal nanoparticles trapped in a biopolymer composite due to electrical conductivity properties improve electrochemical sensors with biomedical and environmental applications. The study aims are to design a novel molecularly imprinted polymer (MIP) composite based on magnetic graphene oxide (Fe3O4@GO) modified silica (SiO2) and gold nanoparticles (AuNPs) to electrochemical detect serotonin (5-hydroxytryptamine, 5-HT). A suitable amount of 5-HT is effective on motivational functions and the environment because it is a serotonergic neurotransmitter. But the desired nanocomposite may have a relatively low recognition, therefore must be in choosing the type of functional monomer be careful. In this regard, the design of the electrochemical sensor began by synthesis of Fe3O4@GO-SiO2@AuNPs nanocomposite. Then, MIP electropolymerization was carried out by using p-aminothiophenol (PATP)-functionalized Fe3O4@GO-SiO2@AuNPs nanocomposite in the presence of 5HT as a template molecule. Electrochemical polymerization of MIP nanocomposite was developed using cyclic voltammetry (CV) and the electrochemical properties of 5-HT were studied use differential pulse voltammetry (DPV) technology in the 5HT solution. After optimization of preparation and measurement conditions on the designed sensor, the 5HT concentration range is 0.1 μM to 10 μM linearly, and the detection limit was 1 × 10-5 μM (S / N = 3). The wide concentration range and low detection limit were presented metal nanoparticles functionalized MIP with appropriate functional monomer have a great effect on the performance of the sensor. Furthermore, PATP-functionalized metal nanoparticles increase the conductivity and recognition of the prepared MIP electrochemical sensor to the quantification of 5-HT in biological samples with high selectivity and recovery.
Raphaël Trouillon
bchm · 2013
Abstract Nitric oxide (NO) is a unique cellular messenger linked to a number of important biological processes. Its free radical nature, small size and fast diffusivity make it highly reactive and membrane permeable. Unfortunately, its reactivity, coupled with the inherent complexity of in situ biological measurements, makes it a challenge to detect. For the past 20 years, electrochemical methods have been used to investigate the role of NO in a number of biological processes, including vascular physiology, immune response, neuronal mediation, tissue growth and oxidative stress. This review examines the biological applications of electrochemical NO sensors and the technologies used to elucidate different physiological phenomena associated with this unique biomolecule with a specific focus on the developments and innovations reported in the last 3 years.
Tadeusz Malinski
Encyclopedia of Electrochemistry · 2002
Abstract The sections in this article are Introduction The Role of Nitric Oxide in Biological Systems NO Release in Biological Systems NO as a Regulator of the Cardiovascular System NO in the Nervous System NO as a Part of the Immune System Pathology of NO Release Electrochemical Methods for NO Detection Electrochemical Oxidation of NO Preparation of Porphyrinic Sensor Operation Modes Clark Probe for NO Detection Measurement of NO in Biological Systems Measurement of NO in a Single Cell In vitro Measurement of NO in Tissue In vivo Measurements of NO in the Kidney In vivo Measurements of NO in the Beating Heart Measurement of NO in the Brain In vitro Measurement with Clark Probe In vivo Measurement with Porphyrinic Sensor Measurements of NO in Human Beings
KOJI TANABE, YOSHITAKA YOSHIZUMI, SHINNOSUKE TSUCHIYA et al.
Electronics and Communications in Japan · 2017
SUMMARY There is a strong interest in onsite rapid analysis and monitoring of the activity of cells and biological samples. Such analyses contribute not only to the understanding of cell functions, but also to the improvement of point‐of‐care testing and quality‐of‐life. In promoting miniaturization and integration of sensing components, electrochemistry is advantageous. By coupling this technique with microfluidic techniques, additional functions that can never be realized with only independent sensors can be realized. In this review paper, we introduce our recent electrochemical devices, particularly focusing on analyses of cell functions and biological samples.
Chanika Pinyorospathum
· 2018
This research comprised of 2 parts including (1) lab-on-paper coupled with electrochemical method for C-reactive protein and colorimetric detection for phosphate ions and (2) the development of chromatographic techniques and its applications. In each part, it can be classified in 2 works. The first work of lab-on-paper is the electrochemical sensor that was fabricated from phosphorylcholine assembled electrodeposited gold nanoparticles onto screen-printed carbon electrode for C-reactive protein detection. Current of ferrocyanide decrease linearly when increase C-reactive protein concentration from 5.0 – 5000 µg L⁻¹. The calculated detection limit equals 1.60 µg L⁻¹. The final part of lab-on-paper is the colorimetry on paper for phosphate ions using 2-mercaptoethanesulfonate modified silver nanoplates. The color changes rely on anti-aggregation mechanism of modified silver nanoplates and europium ions. The paper-based analytical device can use the naked-eye for detection from purple color changing to pink when increase phosphate concentration. The linearity and detection limit are in the range of 1.0 – 30 mg L⁻¹ and 1.0 mg L⁻¹, respectively. For the development of chromatographic techniques and its applications, the first part is the separation of 4 important insecticides; dinotefuran, thiamethoxam, clothianidin, and imidacloprid using ultra-high-performance liquid chromatography coupled with amperometry detection. The complete separation was finished within 8 minutes using reverse-phase chromatography. The analytical signals increase when employing electrodeposited copper-gold nanoparticles. The detection limit and linear range of 4 significant insecticides were in the range of 0.19 – 0.62 mg L⁻¹ and 1.0 – 250 mg L⁻¹, respectively. The second work is the separation of amino acids using open tubular liquid chromatography. The current signals were measured on copper electrode. The separation of amino acids depends on the ion exchange affinity between quaternary amine on the resin and amino acids. The electrochemical detection arises from the oxidation of copper to form complexes between copper and amino acid. The developed method has detection limit of 0.42 mg L⁻¹. Moreover, all presented methods are simple, fast, and inexpensive. The methods are applied in real samples covering food, environmental compounds, and biomarkers.
Andrea Cognigni, Isabella Ascone, Silvia Zamponi et al.
Journal of Synchrotron Radiation · 2001
A new `quasi-solid state' spectroelectrochemical cell for in situ XAS measurements is described and tested using microperoxidase as reference material. The cell substantially improves conventional thin layer cells used for solution XAS spectroelectrochemistry in terms of assembling time and, more important, equilibration of the redox system under study with the applied potential. Spectra can be, in fact, recorded simultaneously during a slow scan rate cyclic voltammetric scan thus permitting correlation of the spectra and the electrochemical curve. Other advantages are the possibility to use very small quantities of material also with second-generation rings. With high intensity sources having focussed beams a further decrease of the specimen weight can be easily obtained and the acquisition time of spectra further reduced.
Senzekile Majola
· 2021
Green nanomaterial synthesis has become more popular and, with the need for greener approaches to counter higher costs and higher energy usage for chemical and physical processes, scientists are searching for cheaper methods of synthesis. The use of plant extracts has been one of the popular methods because they are known to reduce metal ions from their surface. Green synthesized nanomaterials are relatively unstable compared to chemical and physical methods hence new stabilizing agents (indole pyrazole ligands) have been introduced in this study. The nanomaterials are being applied in electrochemical and biological systems, their behavior may not be as efficient as the new capped nanomaterials. Hence, a comparison of capped and uncapped nanomaterials was studied. Indole pyrazole capped selenium nanoparticles (TRPIDC-CH3 SeNPs), Indole pyrazole capped silver nanoparticles (TRPIDC-CH3 AgNPs), and Indole pyrazole capped cadmium sulphide quantum dots (TRPIDC-CH3 CdSQDs) were successfully synthesized using plant extracts of allium sativum cloves, pelargonium, and moringa leaves, respectively. Green synthesized TRPIDC-CH3 capped nanomaterials were characterized by UV-vis spectrophotometry, HR-TEM, and FTIR analysis. The results revealed no differences in shape, color, functional groups involved, or wavelength, but an increase in average diameter as compared to uncapped nanomaterials. Furthermore, green-fabricated synthesized nanomaterials were tested to evaluate their cytotoxicity against MCF-7, A549, and HEK293 cells. The overall cytotoxicity was low: a dose-dependent increase in cytotoxic activity was observed for each of the nanomaterials, as the concentration increased from 50 μg/ml to 100 μg/ml. Interaction of TRPIDC-CH3 capped and uncapped nanomaterials with human serum albumin (HSA) was investigated under physiological conditions (PBS, pH 7.3) by UV–Vis, and fluorescence. Fluorescence analysis at different temperatures revealed the quenching of HSA. The results showed a single class of binding site and a static ( uncapped) and dynamic (TRPIDC-CH3 capped) quenching mechanism between nanomaterials and HSA. The thermodynamic results indicated van der Waals forces and hydrogen bonds (uncapped) and hydrophobic interactions (TRPIDC-CH3 capped) were dominant. Dual enzyme electrode for the indirect detection of adenosine triphosphate (ATP),using a redox probe as a reference peak, was developed by co-immobilization of the enzymes glucose oxidase (GO) and hexokinase (Hex) and nanomaterials. The implementation of a simple electrochemical technique to co-immobilize enzymes on electrode surfaces demonstrates a significant improvement in the sensitivity, reproducibility and ease of fabrication of ATP biosensors. However, the addition of the TRPIDC-CH3 ligand to QDs affected the surface area and conductive activity of the sensor leading to a decrease in sensitivity and weakening the electrochemical stability of the QDs. The concept proposed provides the technological basis for a new generation of fast, responsive and robust biosensors for the detection of ATP through indirect detection. Keywords: Adenosine triphosphate (ATP); Indole pyrazole ligand (TRPIDC-CH3); Selenium Nanoparticles (SeNPs); Cyclic voltammetry (CV); Square wave voltammetry (SWV); Hexokinase (Hex); Glucose oxidase (GO); Human serum albumin (HSA); MTT assay; MCF-7, A549, and HEK293 cells.
So Tanabe, Shuyi Sun, Satohiro Itagaki et al.
ECS Meeting Abstracts · 2020
A better understanding of the biological functions of microorganism is required to reduce their threats and increase their usefulness. Therefore, an importance of real-time evaluation of bacterial activity increase for various purposes such as hygiene management, development of antibacterial agents, and effective utilization of bacterial resources. 1 This necessitates a quantitative assessment of metabolic processes, including growth and respiration. Here we would like to introduce the development of electrochemical methods for assessing bacterial activity. Electrochemical detection of viable bacterial cells was performed using cell membrane permeable electron mediator and redox active pigment. Shewanella oneidensis MR-1 transfers electrons generated within the cell to the extracellular environment via the cytochrome complex in the inner/outer membranes and is one of the most useful bacteria for the recovery of metals, treatment of wastewater, and preparation of microbial fuel cells. By using potentiometric measurements, we have examined intracellular electron generation in bacterial suspensions of S. oneidensis supplemented with different carbon sources or ferricyanide, which was almost completely reduced to ferrocyanide during the incubation without affecting bacterial cell viability. 2 On the other hand, a tetrazolium salt (MTT), which was converted to an insoluble reduction form (formazan) through the respiration of microbial cells. 3 The insolubility of this formazan was effectively exploited as a surface-confined redox event. The electrochemical detection of formazan was effectively coupled with the thermal lysis of microbes. The sensitivity of the present technique is up to 10,000-fold higher than that of MTT colorimetry and requires an incubation time of only 1 h, which is approximately 1/4 of that required for other metabolism-based techniques. Furthermore, the measurement of the reduction current of dissolved oxygen provides an effective mean for assessing the respiratory activity of bacteria in suspension. 4 1) T. Kinoshita, K. Ishiki, D. Q. Nguyen, H. Shiigi, T. Nagaoka, Anal. Chem. , 90 (6), 4098 (2018). 2) K. Ishiki, H. Shiigi, Anal. Chem. , 91 (22), 14401-14406 (2019). 3) K. Ishiki, D. Q. Nguyen, A. Morishita, H. Shiigi, T. Nagaoka, Anal. Chem. , 90 (18), 10903 (2018). 4) M. Saito, K. Ishiki, D. Q. Nguyen, H. Shiigi, Anal. Chem. , 91 (20), 12793-12798 (2019).
Beth A. McCormick, Beth A. McCormick, Beth A. McCormmick et al.
Cambridge University Press eBooks · 2006
An emerging theme in molecular and cellular microbiology has been the ability of many pathogens to usurp the host cell and eventually colonize the host. This interaction between bacteria and host is not unidirectional - both pathogens and host cells engage in a signalling cross-talk. Research focused on this cross-talk and discussed in this volume, reveals not only novel aspects of bacterial pathogenesis, but also key information about epithelial biology with broader implications in the prevention and treatment of infectious diseases. Written by leading researchers in this field, this book provides a valuable overview of the host-bacterial interactions that occur at mucosal surfaces including the gastrointestinal, respiratory, and urogenital tracts. It will therefore be a valuable resource for graduate students and researchers working on these systems or in the fields of molecular and cellular microbiology or infectious disease medicine.
Yaniv Shlosberg
bioRxiv (Cold Spring Harbor Laboratory) · 2023
Abstract In recent years, big efforts are done to develop new clean energy technologies that will supply the increasing energy demand without contaminating the environment. One of the approaches is the utilization of live organisms as electron donors in bio-electrochemical cells. Photosynthetic organisms may apply for photocurrent generation, releasing NADPH molecules that are formed in the photosynthetic pathway. In this work, we show for the first time that photocurrent can be harvested directly from a cherry fruit associated with a bio-electrochemical cell. Furthermore, we apply electrochemical and spectroscopic methods to show that NADH in the fruit plays a major role in electric current production.
David C. Sigee
Cambridge University Press eBooks · 1993
Bringing together bacterial structure and function, taxonomy, environmental microbiology, induction and development of plant disease, molecular genetics and disease control, Dr Sigee unifies the field, at the same time as emphasising exciting developments in cell and molecular biology. The book is written in a clear and concise manner, illustrated with numerous tables, diagrams and photographs.
Paola Bardetti, Felix Barber, Enrique R. Rojas
bioRxiv (Cold Spring Harbor Laboratory) · 2024
Abstract The bacillus - or rod - is a pervasive cellular morphology among bacteria. Rod-shaped bacteria elongate without widening by reinforcing their cell wall anisotropically, along the cell’s circumference, but it is unknown how cells adaptively tune anisotropy to homeostatically control cell width. Through super-resolution measurements of cell wall mechanical properties, we discovered that the Bacillus subtilis cell wall exhibits non-linear stress-softening exclusively in the circumferential direction. Furthermore, during steady-state growth the cell wall is inflated precisely to the acute non-linear transition. Physics-based theory correctly predicted that this transition underlies the negative feedback that governs cell width homeostasis. In other words, the cell wall is a “smart material” whose exotic mechanical properties are exquisitely adapted to execute cellular morphogenesis.
Dan Dan
Research Square · 2020
Abstract The field of electrochemistry can be defined as the set of physical and chemical phenomena involved by the passage of an electric current in an ionic conductor. These phenomena involve the use of electrodes characterized by at least one interface common to two conductors of different nature. They manifest themselves in various ways in electrochemical reactors made up of two electronic conductors or electrodes separated by an ionic conductive medium. After having defined the main phenomena involved in the flow of current, the article presents the thermodynamic and kinetic aspects of electrochemistry (electrochemical cell). The main industrial applications of electrochemistry are briefly presented.
Arijit Bag
ChemRxiv · 2017
Extraction of electricity from the salinity gradient of sea water-river water interface has drawn the key interest of sustainable energy researchers. Different technologies are in the spot light − such as pressure retarded osmosis, reverse electrodialysis, ionic diode membrane, mixing entropy battery, microbial fuel cell, etc. In the present work, electrochemical cell equipment is used for this purpose. Two different techniques are described − galvanic cell equipment (GCEQ) and concentration cell equipment (CCEQ). It is observed that, the extracted energy density is very high (up to 95 W m −2 ) compared with the other methods of the same kind reported so far. Implementation of these methods is trivial. Thus, we may conclude that present method will fulfill our requirement of sustainable energy resource.
Mongkol Tipplook
· 2015
Bacterial cellulose (BC) pellicle is a polysaccharide produced by Acetobacler xylinum. BC pellicle is a good candidate for being used as a wound dressing material because it can provide a moist and promote the wound healing process. However, in a large scale production of BC pellicle the uniformity of thickness of thickness of BC pellicle and its durability are matters of great concerns. In this study, Acetobacter xylinum cells were immobilized on surfaces of a cotton fabric before cultivation in a culture medium in order to produce a BC composite reinforeed with the cotton fabric. Furthermore, a surface treatment of the cotton fabric by using plasma and chemical treatments were performed in order to enhance the attachment of the bacterial cells on the surfaced. The results on cytotoxicity evaluated by MTT assay indicated that the BC composites were non-toxic to L929 cells. The SEM images showed that density of cellulose fibers attached on the cotton fabric was greater than non-immobilized one. Although the production yields of BC composites obtained by applying cell immobilization techniques were slightly less than that produced by traditional techniques (non-immobilization), the use of less starting cell inoculum and the uniformity of BC deposited on the cotton fabric are the benefits of applying cell immobilization on the production of BC composites.
S. Keerthana, K. P. Divya, A. Rajapriya et al.
Research Square · 2024
Abstract Pyocyanin (PYO) is a distinctive electroactive virulence factor secreted by Pseudomonas aeruginosa , a bacterium implicated in a spectrum of severe human infections, particularly in susceptible and critically ill patients. The rapid and accurate diagnosis of infectious agents is crucial for prescribing effective antibiotics and ensuring successful treatment outcomes in patients facing critical conditions. Due to its redox-active nature, PYO actively participates in electron acceptance and donation processes at the electrode surface, making it well-suited for electrochemical detection. To enhance this detection capability, we utilized a physically cross-linked methodology to embellish the surface of a working electrode with a nanocomposite composed of tungsten disulfide nanosheets supported by nanodiamond (WS 2 NSs-ND). This innovative approach was implemented to enhance electron transport, and sample absorption on the electrode surface with a sensitivity of 0.38 µA µM − 1 cmdue to its increased number of active sites. Furthermore, WS 2 NSs-ND demonstrated remarkable electrochemical performance when applied to real sample human urine, yielding RSD of ± 2%. This underscores the reliability and robustness of WS 2 NSs-ND/GCE for the accurate detection of PYO in diverse biological samples, showcasing its potential for clinical applications.