Rabeay Y. A. Hassan, Maha A. Sultan, Maha M. Abou El‐Alamin et al.

Electroanalysis • 2017

Abstract For the first time, the use of carbon nanotubes was exploited for the development of a sensitive electrochemical method for determination of the newly antifungal posaconazole (POS). The electrochemical activity of POS was investigated at the surface of multi‐walled nanotubes (MWNTs) modified electrode. The cyclic voltammograms showed a sharp oxidation peak at potential around 671 mV vs. Ag/AgCl. To reach the assay optimization, factors affecting the method sensitivity have been investigated, such as types of carbon nanotubes and its concentration in the electrode matrix, type of supporting electrolyte, pH, accumulation time and scan rate. A good linear relationship was obtained within the concentration range from 32–1280 ng/ml with the limit of detection and quantification of 11 ng/ml and 33 ng/ml, respectively. The proposed method was successfully applied for the determination of POS in its commercial dosage form, spiked human plasma samples, and dried blood spots. The in vivo results obtained were also used to study the pharmacokinetics of POS in human plasma. The results obtained were validated and found to be in accordance with those obtained by the reference methods.

L Bartalits, G Nagy, E Pungor

Clinical Chemistry • 1984

Abstract This amperometric technique for the determination of enzyme activity is based on detecting a decrease in the concentration of the NADH co-factor of the enzyme reaction. A glassy carbon electrode, modified by adsorption of Mg2+ and NADH, is used to measure the anodic peak current that corresponds to the oxidation of NADH. We found no significant difference between the enzyme activity of lactate dehydrogenase (E.C.1.1.1.27) preparations as measured by the above amperometric technique and by a spectrophotometric method.

D. J. Daly, C. K. O'Sullivan, G. G. Guilbault

Biochemical Society Transactions • 2000

The use of electrochemically grown polymers has expanded dramatically in the last couple of years, and they are now well established as membranes for immobilizing components. The evidence here for their anti-fouling properties is good. The poly(1,3-diaminobenzene)-covered electrodes performed well in the buffer, urine, plasma and serum samples, but not so well in the blood. The Ru/Rh/Pt, Rh/Rh and the Pt-on-glassy carbon electrodes covered with poly(1,3-diaminobenzene) were the best electrodes in the blood. The Pt disc seemed to exhibit the largest irrepeatability in most of the biological matrices.

Lin Zhang, Neus Vilà, Alain Walcarius et al.

ChemElectroChem • 2018

Abstract A generic approach has been developed for sequential heterogeneous surface modification of electrodes. The strategy, which is applicable for a wide range of functional groups, involves two main steps. In the first one, azide‐alkene bifunctionalized electrodes are obtained by electrochemical reduction of a mixture of diazonium salts generated in situ from the corresponding 4‐azidoaniline and 4‐vinylaniline. In that way, we provide reactive sites that are available for further selective functionalization in a sequential process based on ‘click reactions’, in which subsequent immobilization of the targeted molecules is achieved by the azide‐alkyne cycloaddition Huisgen reaction and alkene‐thiol coupling. Feasibility of the method has been first demonstrated for the coimmobilization of two distinct redox moieties (cobaltocenium and ferrocene) as evidenced by cyclic voltammetry and X‐ray photoelectron spectroscopy measurements. The versatility of the sequential method has then been exploited for the coimmobilization of a molecular electrocatalyst [Cp*Rh(bpy) Cl] + and a biological catalyst, a NAD‐dependent dehydrogenase, that were proved to act in cascade in the electroenzymatic reduction of D‐fructose to D‐sorbitol. Such simple combination of diazonium chemistry and robust chemical reactions (‘click chemistry’) is promising for the environmentally friendly heterogeneous modification of electrodes with multiple chemical and biological catalysts.

Fahimeh Jalali, Amir M. Ashrafi, Davood Nematollahi

Electroanalysis • 2009

Abstract A modified carbon paste electrode was constructed for the determination of dissolved oxygen using diamino‐ o ‐benzoquinone (DABQ) as the modifier. The electrochemical behavior of the electrode in citrate buffer (pH 2.0) was studied. In the presence of dissolved oxygen (DO) both cathodic and anodic peak currents decreased, indicating a chemical reaction between modifier and O 2 . The decrease in peak current was linearly proportional to the amount of dissolved oxygen in the concentration range of 252–1260 μM of DO. The electrode was utilized in the determination of DO in urine samples. The relative error and RSD of the method were 1.6% and 4.1%, respectively. The electrode was applied more than two months for the determination of DO without any significant divergence in its voltammetric response.

Yuvarajgouda Patil, Manjunath Megalamani, Jyothi Abbar et al.

ECS Advances • 2024

The electrochemical performance of phenylbutazone (PBZ) was studied using a multi-walled carbon-nanotube-modified paste electrode (MWCNT/CPE) using a variety of voltammetric tools like cyclic voltammetry (CV), linear sweep voltammetry (LSV), and square wave voltammetry (SWV). The results showed that the MWCNT/CPE exhibited remarkable electro-catalytic action towards the electrochemical oxidation of PBZ in a phosphate buffer solution of physiological pH 7 compared to a bare carbon paste electrode. The electro-kinetic parameters like heterogeneous rate constant, transfer coefficient, scan rate, pH, and involvement of electrons in electro-oxidation of PBZ was investigated. For bare CPE, the peak current was noted to be 19.53 μ A with peak potential of 0.6871 V. For MWCNT/CPE, the peak current was 30.53 μ A with peak potential of 0.6792 V. The anodic peak was analyzed, and the process was diffusion controlled. For the estimation of PBZ, a SWV technique was developed with great precision and accuracy, with a detection limit of 5.2 nM and a limit of quantification of 17 nM, in the concentration range 1 × 10 −7 to 10 × 10 −6 M. The MWCNT/CPE has been used successfully for PBZ detection in injection, blood, and urine samples, with recovery rates of 98.9% to 101.5%, 96.3% to101.7% and 98.3% to 102.8%, respectively.

Vera Bocharova, Evgeny Katz

The Chemical Record • 2012

Abstract Electrode interfaces functionalized with various signal‐responsive materials have been designed to allow switchable properties of the modified electrodes. External signals of different nature (electrical potential, magnetic field, light, chemical/biochemical inputs) were applied to reversibly activate–deactivate the electrode interfaces upon demand. Multifunctional properties of the modified interfaces have allowed their responses to complex combinations of external signals. Further increase of their complexity has been achieved by integrating the signal‐responsive interfaces with unconventional biomolecular computing systems logically processing multiple biochemical signals. This approach has resulted in electrochemical systems controlled by complex variations of biomarkers corresponding to different physiological conditions, thus allowing biological control over electronic systems. The switchable electrodes have been integrated with various “smart” biosensing and signal‐processing systems and have been used to assemble biofuel cells producing power on demand. DOI 10.1002/tcr.201100025

A. Heduit, D. R. Thevenot

Water Science and Technology • 1992

The zero current potential of a platinum electrode in a biological medium (wastewater, activated sludge) is strongly dependent on the surface characteristics of the metal. It is also influenced by pH (probably Pt/PtO system), dissolved oxygen (O2/OH- system), and ionic forms of nitrogen (NO2-/NH4+ and NO3-/NO2-systems). The experimental values of the coefficients relating the stabilized potential of a platinum electrode to the logarithm of the concentration of the elements under consideration (Nernst equations) are significantly different from the thermodynamic coefficients corresponding to each reaction. The platinum is thus not in equilibrium with the dissolved redox reactants and is likely subject to mixed potentials in which the adsorbed components play an important role.

Krishnaveni Venkidusamy, M. Megharaj

Frontiers in Microbiology • 2016

Electrode respiring bacteria (ERB) possess a great potential for many biotechnological applications such as microbial electrochemical remediation systems (MERS) because of their exoelectrogenic capabilities to degrade xenobiotic pollutants. Very few ERB have been isolated from MERS, those exhibited a bioremediation potential toward organic contaminants. Here we report once such bacterial strain, Stenotrophomonas maltophilia MK2, a facultative anaerobic bacterium isolated from a hydrocarbon fed MERS, showed a potent hydrocarbonoclastic behavior under aerobic and anaerobic environments. Distinct properties of the strain MK2 were anaerobic fermentation of the amino acids, electrode respiration, anaerobic nitrate reduction and the ability to metabolize n-alkane components (C8–C36) of petroleum hydrocarbons (PH) including the biomarkers, pristine and phytane. The characteristic of diazoic dye decolorization was used as a criterion for pre-screening the possible electrochemically active microbial candidates. Bioelectricity generation with concomitant dye decolorization in MERS showed that the strain is electrochemically active. In acetate fed microbial fuel cells (MFCs), maximum current density of 273 ± 8 mA/m2 (1000 Ω) was produced (power density 113 ± 7 mW/m2) by strain MK2 with a coulombic efficiency of 34.8%. Further, the presence of possible alkane hydroxylase genes (alkB and rubA) in the strain MK2 indicated that the genes involved in hydrocarbon degradation are of diverse origin. Such observations demonstrated the potential of facultative hydrocarbon degradation in contaminated environments. Identification of such a novel petrochemical hydrocarbon degrading ERB is likely to offer a new route to the sustainable bioremedial process of source zone contamination with simultaneous energy generation through MERS.

Rong Liu, Lina Ma, Shu-Chen Huang et al.

The Journal of Physical Chemistry C • 2016

Flexible energy storage devices require a simple, scalable and general strategy for fabricating high electrochemical performance and mechanically tough flexible electrodes. Herein, sustainable and biological bacterial cellulose (BC) is developed as substrate for Co3O4/graphene (GN), which permits high flexibility (suitable for bending angle of 180°), excellent tensile strength of 63 MPa, good wettability, and especially large mass loading of 9.61 mg cm–2 for a flexible and free-standing supercapacitor electrode. The Co3O4/GN/BC hybrid electrode exhibits both appreciable areal capacitance of 12.25 F cm–2 and gravimetric capacitance of 1274.2 F g–1. Moreover, the remarkable cycling stability with 96.4% capacitance retention after 20000 can be achieved. This study provides a facile procedure to improve the electrochemical performance and mechanical property of flexible supercapacitor electrodes, which are promising candidates for the application of a flexible power source.

N. Zhang, Lina Yue, Yajie Xie et al.

IEEE Journal of Translational Engineering in Health and Medicine • 2018

We propose a flexible, dry, and antibacterial electrode with a low and stable skin electrode contact impedance for bio-potential signal monitoring. We fabricated a bacterial cellulose/polyaniline/AgNO3 nanocomposite membrane (BC/PANI/AgNO3) and used it for bio-potential signal monitoring. The bacterial cellulose (BC) provides a 3-D nanoporous network structure, and it was used as a substrate material in the BC/PANI/AgNO3 nanocomposite membrane. Polyaniline (PANI) and AgNO3, acting as conductive and antibacterial components, respectively, were polymerized and deposited on the surfaces of BC nanofibers to produce uniform thin film membrane with flexible, antibacterial, and conductive properties. Various measurements were conducted, in terms of antibacterial activity, skin electrode contact impedance, and qualitative analysis of ECG signal recordings. The BC/PANI/AgNO3 membrane revealed 100% antibacterial activities against both the Staphylococcus aureus and Escherichia coli bacteria. The skin electrode contact impedance of the proposed BC/PANI/AgNO3 electrode is lower than that of the Ag/AgCl gel electrode, with the same active area. In addition, the electrocardiogram (ECG) signals acquired with the proposed electrodes have stable characteristic waveforms, and they are not contaminated by noise. The waveform fidelity of the BC/PANI/AgNO3 membrane electrodes over 800 ECG cardiac cycles is 99.49%, and after the electrodes were worn for 24 hours, a fidelity of 98.40% was recorded over the same number of cardiac cycles. With the low and stable skin electrode contact impedance, the proposed dry BC/PANI/AgNO3 membrane electrode provided high fidelity for ECG signal recordings, thus offering a potential approach for bio-potential signal monitoring. With the above benefits, the novel flexible and dry BC/PANI/AgNO3 electrode has a significant antibacterial. Most of all, it is the first research to develop antibacterial in the electrode design.

I. Hwang, Jongku Jeong, Taesuk You et al.

Biotechnology & Biotechnological Equipment • 2018

ABSTRACT The present study used water-electrode plasma discharge to increase the effect of bacterial inactivation in water for bioengineering and biotechnological applications. The water-electrode plasma discharge system was fabricated using a newly designed plasma generator and a high-voltage power supply. Water contaminated with Escherichia coli was treated with water-electrode plasma discharge for 0, 1, 2, 3, 4, 5, 10, 20 and 30 min. As a result, the colony-forming units (cfu) of E. coli were reduced with plasma treatment time, reaching nearly complete inactivation after 30 min. In addition, rapid generation of H2O2 in the contaminated water was observed, which could mainly account for the effective bacterial inactivation. In conclusion, direct generation of reactive chemical species under water was successfully achieved by using a water-electrode plasma discharge system, which could be practically used to enhance bacterial inactivation in a variety of bioengineering applications.

Chang-Ho Han, Hyunsu Ha, Jaesung Jang

Lab on a Chip • 2019

An array of microfabricated interdigitated electrodes (IDEs) is one of the most commonly used forms of electrode geometry for dielectrophoretic manipulation of biological particles in microfluidic biochips owing to simplicity of fabrication and ease of analysis. However, the dielectrophoretic force dramatically reduces as the distance from the electrode surface increases; therefore, the effective region is usually close to the electrode surface for a given electric potential difference. Here, we present a novel two-dimensional computational method for generating planar electrode patterns with enhanced volumetric electric fields, which we call the "microelectrode discretization (MED)" method. It involves discretization and reconstruction of planar electrodes followed by selection of the electrode pattern that maximizes a novel objective function, factor S, which is determined by the electric potentials on the electrode surface alone. In this study, IDEs were used as test planar electrodes. Two arrays of IDEs and respective MED-optimized electrodes were implemented in microfluidic devices for the selective capture of Escherichia coli against 1 μm-diameter polystyrene beads, and we experimentally observed that 1.4 to 35.8 times more bacteria were captured using the MED-optimized electrodes than the IDEs (p < 0.0016), with a bacterial purity against the beads of more than 99.8%. This simple design method offered simplicity of fabrication, highly enhanced electric field, and uniformity of particle capture, and can be used for many dielectrophoresis-based sensors and microfluidic systems.

Lizeng Zuo, W. Fan, Youfang Zhang et al.

Nanoscale • 2017

Electroactive materials, such as nickel sulfide (NiS), with high theoretical capacities have attracted broad interest to fabricate highly efficient supercapacitors. Preventing aggregation and increasing the conductivity of NiS particles are key challenging tasks to fully achieve excellent electrochemical properties of NiS. One effective approach to solve these problems is to combine NiS with highly porous and conductive carbon materials such as carbon aerogels. In this study, a green and facile method for the in situ growth of NiS particles on bacterial cellulose (BC)-derived sheet-like carbon aerogels (CAs) has been reported. CA prepared by the dissolution-gelation-carbonization process was used as a framework to construct NiS/CA composite aerogels with NiS uniformly decorated on the pore walls of CA. It was found that the NiS/CA composite aerogel electrodes exhibit excellent capacitive performance with high specific capacitance (1606 F g-1), good rate capacitance retention (69% at 10 A g-1), and enhanced cycling stability (91.2% retention after 10 000 continuous cyclic voltammetry cycles at 100 mV s-1). Furthermore, asymmetric supercapacitors (ASCs) were constructed utilizing NiS/CA composite and CA as the positive and negative electrode materials, respectively. Through the synergistic effect of three-dimensional porous structures and conductive networks derived from CA and the high capacitive performance offered by NiS, the ASC device exhibited an energy density of ∼21.5 Wh kg-1 and a power density of 700 W kg-1 at the working voltage of 1.4 V in 2 M KOH aqueous solution. The ASC device also showed excellent long-term cycle stability with ∼87.1% specific capacitance retention after 10 000 cycles of cyclic voltammetry scans. Therefore, the NiS/CA composite shows great potential as a promising alternative to high-performance electrode materials for supercapacitors.

Jun Xing, S. Qi, Zhengao Wang et al.

Advanced Functional Materials • 2019

Conductive polymer electrodes are widely used for electrical signal detection owing to their unique mechanical, redox, and impedance characteristics. However, the performance of electrodes is compromised due to the interference of adhered bacteria and most of the scientists have not taken the microbial environment into consideration during electrode design. Here, a facile approach to construct antimicrobial peptide (AMP) functionalized polypyrrole nanowire array conductive electrodes (PNW‐AMP) is reported. Instead of compromising the electrochemical properties as the other antibacterial agents do, the PNW‐AMP electrodes exhibit excellent redox and low interfacial impedance properties. More importantly, the PNW‐AMP can eliminate bacterial adhesion and maintain electrochemical stability simultaneously in the microbial microenvironment for a long time. The antibacterial rate of the PNW‐AMP electrode reaches 95.8% after exposing the electrode to air for one month, while the charge transfer resistance ( Rct) value only increases by 9% at a bacterium (Escherichia. Coli ) concentration of 1 × 104 colony forming unit (CFU) mL−1. This research makes it possible to construct highly stable conductive polymer electrodes for bacterial environment electrical signal detection.

G. Ihn, S. T. Woo, Moo-jeong Sohn et al.

Analytical Letters • 1989

Abstract A bacterial electrode for the determination of urea has been constructed by immobilizing the Proteus mirabilis on a carbon dioxide gas-sensor. the electrode gave a Nernstian behaviour between 7.0 × 10−4 and 3.0 × 10−2 M urea with a slope of 46 mV/decade in pH 6.80, 0.1M phosphate buffer at 30°C. the important interferences were L-asparagine, cytosine, inositol and phenol, and most inorganic salts reacted as the inhibitor. This electrode showed little change in the response and linear rane for 7 days, and could also be used in the linear range because the electrode had good reproducibility even after this. This device could be used as easily and exactly as a spectrophotometric method in clinical applications.

Yi-Ru Luo, Wenxiu Que, Yi Tang et al.

ACS Nano • 2024

Ultrathin MXene-based films exhibit superior conductivity and high capacitance, showing promise as electrodes for flexible supercapacitors. This work describes a simple method to enhance the performance of MXene-based supercapacitors by expanding and stabilizing the interlayer space between MXene flakes while controlling the functional groups to improve the conductivity. Ti3C2Tx MXene flakes are treated with bacterial cellulose (BC) and NaOH to form a composite MXene/BC (A-M/BC) electrode with a microporous interlayer and high surface area (62.47 m2 g-1). Annealing the films at low temperature partially carbonizes BC, increasing the overall electrical conductivity of the films. Improvement in conductivity is also attributed to the reduction of -F, -Cl, and -OH functional groups, leaving -Na and -O functional groups on the surface. As a result, the A-M/BC electrode demonstrates a capacitance of 594 F g-1 at a current density of 1 A g-1 in 3 M H2SO4, which represents a ∼2× increase over similarly processed films without BC (309 F g-1) or pure MXene (298 F g-1). The corresponding device has an energy density of 9.63 Wh kg-1 at a power density of 250 W kg-1. BC is inexpensive and enhances the overall performance of MXene-based film electrodes in electronic devices. This method underscores the importance of functional group regulation in enhancing MXene-based materials for energy storage.

Likkhasit Wannasen, E. Swatsitang, S. Pinitsoontorn

International Journal of Energy Research • 2020

A flexible electrode of NH4CoPO4 · H2O composite bacterial cellulose (Co‐BC) has been successfully prepared via a hydrothermal method. A bacterial cellulose (BC) membrane was used as a host matrix for nanocrystalline (NC) NH4CoPO4 · H2O. The preparation process included anchoring nanocrystalline NH4CoPO4 · H2O on BC nanofibers with an intrinsic 3D network structure. X‐ray diffraction (XRD) results indicated the orthorhombic structure of the NH4CoPO4 · H2O NC within the Pmn21 space group and BC of a Type‐I structure. FE‐SEM images revealed microplate‐like NH4CoPO4 · H2O structures on BC nanofibers. The a three‐electrode system of all samples were studied for their electrochemical properties by CV, charge/discharge and EIS estimations in a 3 M KOH electrolyte. A maximal specific area capacitance of 158.5 mF cm−2 (43.3 F g−1) was obtained at a current density of 0.25 mA cm−2 using a Co‐BC90 electrode. Moreover, this sample show an excellent capacitance retention of 99% after a 3000 cycle at 1 mA cm−2 current density.

Anjana Ratheesh, L. Elias, Sheik Muhammadhu Aboobakar Shibli

ACS Applied Bio Materials • 2021

The study of bacterial adhesion and its consequences has great significance in different fields such as marine science, renewable energy sectors, soil and plant ecology, food industry, and the biomedical field. Generally, the adverse effects of microbial surface interactions have attained wide visibility. However, herein, we present distinct approaches to highlight the beneficial aspects of microbial surface interactions for various applications rather than deal with the conventional negative aspects or prevention strategies. The surface microbial reactions can be tuned for useful biochemical or bio-electrochemical applications, which are otherwise unattainable through conventional routes. In this context, the present review is a comprehensive approach to highlight the basic principles and signature parameters that are responsible for the useful microbial-electrode interactions. It also proposes various surface tuning strategies, which are useful for tuning the electrode characteristics particularly suitable for the enhanced bacterial adhesion and reactions. The tuning of surface characteristics of electrodes is discussed with a special reference to the Microbial Fuel Cell as an example.

Xiaolong Li, Libei Yuan, Rong Liu et al.

Advanced Energy Materials • 2021

The fabrication of highly durable, flexible, all‐solid‐state supercapacitors (ASCs) remains challenging because of the unavoidable mechanical stress that such devices are subjected to in wearable applications. Natural/artificial fiber textiles are regarded as prospective materials for flexible ASCs due to their outstanding physicochemical properties. Here, a high‐performance ASC is designed by employing graphene‐encapsulated polyester fiber loaded with polyaniline as the flexible electrodes and bacterial cellulose (BC) nanofiber‐reinforced polyacrylamide as the hydrogel electrolyte. The ASC combines the textile electrode capable of arbitrary deformation with the BC‐reinforced hydrogel with high ionic conductivity (125 mS cm−1), high tensile strength (330 kPa), and superelasticity (stretchability up to ≈1300%), giving rise to a device with high stability/compatibility between the electrodes and electrolyte that is compliant with flexible electronics. As a result, this ASC delivers high areal capacitance of 564 mF cm−2, excellent rate capability, good energy/power densities, and more importantly, superior mechanical properties without significant capacitance degradation after repeated bending, confirming the functionality of the ASC under mechanical deformation. This work demonstrates an effective design for a sufficiently tough energy storage device, which shows great potential in truly wearable applications.

Kunpeng Gao, Nailong Wu, Bowen Ji et al.

Sensors • 2023

In this paper, we present a soft and moisturizing film electrode based on bacterial cellulose and Ag/AgCl conductive cloth as a potential replacement for gel electrode patches in electroencephalogram (EEG) recording. The electrode materials are entirely flexible, and the bacterial cellulose membrane facilitates convenient adherence to the skin. EEG signals are transmitted from the skin to the bacterial cellulose first and then transferred to the Ag/AgCl conductive cloth connected to the amplifier. The water in the bacterial cellulose moisturizes the skin continuously, reducing the contact impedance to less than 10 kΩ, which is lower than commercial gel electrode patches. The contact impedance and equivalent circuits indicate that the bacterial cellulose electrode effectively reduces skin impedance. Moreover, the bacterial cellulose electrode exhibits lower noise than the gel electrode patch. The bacterial cellulose electrode has demonstrated success in collecting α rhythms. When recording EEG signals, the bacterial cellulose electrode and gel electrode have an average coherence of 0.86, indicating that they have similar performance across different EEG bands. Compared with current mainstream conductive rubber dry electrodes, gel electrodes, and conductive cloth electrodes, the bacterial cellulose electrode has obvious advantages in terms of contact impedance. The bacterial cellulose electrode does not cause skin discomfort after long-term recording, making it more suitable for applications with strict requirements for skin affinity than gel electrode patches.

Qijing Liu, Wenliang Xu, Qinran Ding et al.

Advanced Science • 2024

Interfacial electron transfer between electroactive microorganisms (EAMs) and electrodes underlies a wide range of bio‐electrochemical systems with diverse applications. However, the electron transfer rate at the biotic‐electrode interface remains low due to high transmembrane and cell‐electrode interfacial electron transfer resistance. Herein, a modular engineering strategy is adopted to construct a Shewanella oneidensis‐carbon felt biohybrid electrode decorated with bacterial cellulose aerogel‐electropolymerized anthraquinone to boost cell‐electrode interfacial electron transfer. First, a heterologous riboflavin synthesis and secretion pathway is constructed to increase flavin‐mediated transmembrane electron transfer. Second, outer membrane c‐Cyts OmcF is screened and optimized via protein engineering strategy to accelerate contacted‐based transmembrane electron transfer. Third, a S. oneidensis‐carbon felt biohybrid electrode decorated with bacterial cellulose aerogel and electropolymerized anthraquinone is constructed to boost the interfacial electron transfer. As a result, the internal resistance decreased to 42 Ω, 480.8‐fold lower than that of the wild‐type (WT) S. oneidensis MR‐1. The maximum power density reached 4286.6 ± 202.1 mW m−2, 72.8‐fold higher than that of WT. Lastly, the engineered biohybrid electrode exhibited superior abilities for bioelectricity harvest, Cr6+ reduction, and CO2 reduction. This study showed that enhancing transmembrane and cell‐electrode interfacial electron transfer is a promising way to increase the extracellular electron transfer of EAMs.

R. Maallah, A. Chtaini

Pharmaceutica Analytica Acta • 2018

Voltametric degradation of phenol was carried out at microbial electrode. This electrode is based on graphite carbon and natural phosphate modified by bacteria inserted in the phosphate matrix, the whole is covered by a polymer developed in situ on the surface. This electrode, designated subsequently by bacteria-NP-CPE, Showed stable response and was characterized with voltametric methods, as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The experimental results revealed that the prepared electrode could be a feasible for degradation of hazardous phenol pollutants.

Young‐Hoo Kim, Saerom Park, Keehoon Won et al.

Journal of Chemical Technology &amp; Biotechnology • 2013

Abstract Background Bacterial cellulose ( BC )‐based materials have many potential applications in the biomedical field because of their inherent biocompatibility. Carbon nanotubes ( CNTs ) have been used as electrode materials owing to their high electrical conductivity. In this study, BC‐CNT composite electrodes were prepared simply by directly filtering CNTs through BC hydrogel and vacuum drying the BC hydrogel containing the CNTs . Glucose oxidase ( GOx ) was immobilized on BC‐CNT composite electrodes. Results Cyclic voltammograms revealed that the BC‐CNT‐GOx electrodes had a pair of well‐defined peaks. The formal redox potential peak was –496 mV (vs. Ag/ AgCl ), which agreed well with that of FAD / FADH 2 . This result clearly indicates that direct electron transfer occurred between GOx and the BC‐CNT composite electrode. In addition, the GOx immobilized on the electrode retained its catalytic ability to oxidize glucose. Conclusion Conductive BC‐CNT composite films form a good biocompatible electrode for the direct electron transfer of glucose oxidase. They have many potential applications in the biomedical field such as biosensors, biofuel cells, and bioelectronic devices. © 2012 Society of Chemical Industry

Min-Jeong Seong, Kyu-Ri Park, S. J. Kim et al.

Physics of Plasmas • 2025

A diffuse and large-area dielectric barrier discharge (DBD) filled with air and helium gas mixtures was generated by a unipolar nanosecond-pulsed high voltage. A large-gap multiple pin-to-plate electrode was employed to facilitate the insertion of well plates into the plasma discharge. The nanosecond high-voltage-pulsed discharge has unique advantages in producing a diffuse DBD plasma. We examined the changes in the plasma properties upon varying operating parameters such as the gas composition and flow rate, as well as the pulse voltage. Various types of liquid (de-ionized, tap, and saline water, as well as phosphate buffered saline and LB broth) were exposed to the DBD plasma. The physicochemical properties (pH and electrical conductivity) and concentrations of reactive species generated in the treated liquids (such as H2O2, NO2−, and O3, which play central roles in the aqueous-phase chemistry of plasma-treated liquids for bacterial inactivation) were measured as a function of the operating parameters. The nanosecond-pulsed DBD was observed to generate significantly higher level of reactive species in various types of liquid. For investigating the plasma treatment of liquids containing suspended microorganisms, 1 ml of Escherichia coli (E. coli) stock suspension was pipetted into 9 ml of DW. The resulting bacterial suspensions were treated with the DBD plasma for a selected time. Six-log E. coli reduction was achieved after 19 h of incubation. A DBD plasma generated in a gas mixture of ambient air and 2 slm helium exhibited an enhanced inactivation efficacy, which was correlated with the RONS concentration and pH in the plasma-treated liquids.

M. A. Karmali, A. Williams, P. C. Fleming et al.

Journal of Hygiene • 1984

Summary A method using an ammonia electrode is being developed for investigating the deamination of amino acids and amides by bacteria. Application of this method to Campylobacter jejuni and C. coli has led to the demonstration of d -asparaginase activity in some strains. This has allowed the subdivision of both species into d -asparaginase-positive and -negative biotypes. Even though the method is in the developmental stage, it was found to be generally reproducible and easy to perform. Areas for further improving the procedure have been identified. The ammonia electrode offers the theoretical possibility of investigating the breakdown of any amino acid by bacteria. It thus opens up a new and practical approach for separating species and strains, particularly in those bacterial groups that are difficult to subdivide by conventional means.

A. C. Fisher

Oxford University Press eBooks • 1996

Electrode Dynamics provides an introduction to the field of electrode dynamics. The word electrochemistry commonly instils fear in students. This text aims to distil this fear with a gentle introduction to the kinetics of electron transfer reactions, and explores the potential applications of electrochemistry methodology. The early chapters provide a general introduction to the factors which control the rate of an electrode reaction. The later chapters deal with a variety of electrochemical applications including the study of surface processes, reaction mechanisms, electrosynthesis and the combination of electrochemistry with complementary techniques such as spectroscopy.

R.G. KROLL, EMMA R. FREARS, ANITA BAYLISS

Journal of Applied Bacteriology • 1989

An oxygen electrode‐based assay of catalase was developed as a simple method of assessing contamination by bacteria capable of respiration. The method gave a rapid and reasonable quantification of cell numbers in pure cultures and was able to detect 10 3 bacteria/ml in some cases. The sensitivity of the method was dependent on the identity of the culture and when applied to foods the sensitivity was reduced due to the presence of non‐microbial catalase. The use of electropositively charged filters to remove the organisms from the food sample improved the sensitivity and the relationship between catalase activity and cell numbers in some foods.

Mohamed Ghazi Al-Fandi, Nid’a Hamdan Alshraiedeh, Rami Joseph Oweis et al.

Sensor Review • 2018

Purpose This paper aims to report a prototype of a reliable method for rapid, sensitive bacterial detection by using a low-cost zinc oxide nanorods (ZnONRs)-based electrochemical sensor. Design/methodology/approach The ZnONRs have been grown on the surface of a disposable, miniaturized working electrode (WE) using the low-temperature hydrothermal technique. Scanning electron microscopy and energy dispersion spectroscopy have been performed to characterize the distribution as well as the chemical composition of the ZnONRs on the surface, respectively. Moreover, the cyclic voltammetry test has been implemented to assess the effect of the ZnONRs on the signal conductivity between −1 V and 1 V with a scan rate of 0.01 V/s. Likewise, the effect of using different bacterial concentrations in phosphate-buffered saline has been investigated. Findings The morphological characterization has shown a highly distributed ZnONR on the WE with uneven alignment. Also, the achieved response time was about 12 minutes and the lower limit of detection was approximately 103 CFU abbreviation for Colony Forming Unit/mL. Originality/value This paper illustrates an outcome of an experimental work on a ZnONRs-based electrochemical biosensor for direct detection of bacteria.

S. Zamani, Kh. Ghanbari, S. Bonyadi

Analytical Methods • 2023

Metformin is widely used in the treatment of diabetes either alone or in combination with other drugs. Measuring the concentration of this substance is very important both pre-clinically and clinically in the medical monitoring of diabetic patients.

Palaniappan Ramasamy, Gajalakshmi Dakshinamoorthy, Shanmugam Jayashree et al.

Biosensors • 2022

Salmonellosis caused by Salmonella sp. has long been reported all over the world. Despite the availability of various diagnostic methods, easy and effective detection systems are still required. This report describes a dialysis membrane electrode interface disc with immobilized specific antibodies to capture antigenic Salmonella cells. The interaction of a specific Salmonella antigen with a mouse anti-Salmonella monoclonal antibody complexed to rabbit anti-mouse secondary antibody conjugated with HRP and the substrate o-aminophenol resulted in a response signal output current measured using two electrode systems (cadmium reference electrode and glassy carbon working electrode) and an agilent HP34401A 6.5 digital multimeter without a potentiostat or applied potential input. A maximum response signal output current was recorded for various concentrations of Salmonella viz., 3, 30, 300, 3000, 30,000 and 300,000 cells. The biosensor has a detection limit of three cells, which is very sensitive when compared with other detection sensors. Little non-specific response was observed using Streptococcus, Vibrio, and Pseudomonas sp. The maximum response signal output current for a dialysis membrane electrode interface disc was greater than that for gelatin, collagen, and agarose. The device and technique have a range of biological applications. This novel detection system has great potential for future development and application in surveillance for microbial pathogens.

Soheila Ebrahimi-Koodehi, Farhad Esmaeili Ghodsi, Jamal Mazloom

Scientific Reports • 2023

Abstract Recently, metal–organic frameworks (MOFs) and hybrids with biomaterial are broadly investigated for a variety of applications. In this work, a novel dual-phase MOF has been grown on bacterial cellulose (BC) as a biopolymer nano-fibrous film (Ni/Mn-MOF@BC), and nickel foam (Ni/Mn-MOF@NF) using a simple reflux method to explore their potential for photocatalyst and energy storage applications. The studies showed that the prepared Mn and Ni/Mn-MOFs display different structures. Besides, the growth of MOFs on BC substantially changed the morphology of the samples by reducing their micro sized scales to nanoparticles. The nanosized MOF particles grown on BC served as a visible-light photocatalytic material. Regarding the high surface area of BC and the synergistic effect of two metal ions, Ni/Mn-MOF@BC with a lower band gap demonstrates remarkable photocatalytic degradation efficiency (ca. 84% within 3 h) against methylene blue (MB) dye under visible light, and the catalyst retained 65% of its initial pollutant removal properties after four cycles of irradiation. Besides, MOF powders deposited on nickel foam have been utilized as highly capacitive electrochemical electrodes. There, Ni/Mn-MOF@NF electrode also possesses outstanding electrochemical properties, showing a specific capacitance of 2769 Fg −1 at 0.5 Ag −1 , and capacity retention of 94% after 1000 cycles at 10 Ag −1 .

Wenjia Zhang, Hongkai Wu, I‐Ming Hsing

Electroanalysis • 2015

Abstract Formation of biofilm on an electrode surface is usually a prerequisite for efficient electron transfer from electrogenic bacteria onto electrode, and the geometric status of the biofilm governs the generated current. In this study, we propose a real‐time characterization method to track the dynamic formation process of biofilm on electrode using scanning electrochemical microscopy (SECM). Shewanella oneidensis MR‐1 was chosen in this work as an electrogenic model species. A plane electrode at the bottom of a electrochemical cell filled with bacteria suspension was biased at +0.04 V vs. Ag/AgCl as the sole electron acceptor under anaerobic environment, while a movable ultramicroelectrode (UME) was employed to track the localized faradaic current generated by a redox mediator, Ru(NH 3 ) 6 Cl 3 above the bottom electrode. The growth rate of biofilm showed some spatial heterogeneity, which might be explained by inhomogeneous mass transfer and non‐uniformity of electrode surface. The application of SECM into bacterial electrogenesis studies offered a simple and label‐free monitoring method to evaluate the bacteria‐electrode coupling status.

SONTHAYA NUMTHUAM, PHUNSIRI SUTHILUK, TAKAAKI SATAKE

Journal of Food Safety • 2011

ABSTRACT The use of dissolved oxygen (DO) electrode to determine the total number of bacterial contamination in foods was investigated. The DO in food extract solution was measured as the electrical current continuously for 2 h at 30C. The rate of current decrease serves as a potential index for the prediction of bacterial contamination. The additional culture media is necessary for an effective determination of bacteria in shredded cabbage, cooked rice and instant cream sauce samples. The high prediction accuracies ( r ≥ 0.90) were achieved for all sample types when the analysis period was 2 h. The measurement of DO using oxygen electrode provides a rapid and convenient method for the determination of bacteria in foods. PRACTICAL APPLICATIONS In comparison with the traditional microbiological method, the present research could provide more rapid and simple measuring method to improve the existing security level in food process. In order to support the food industry and market needs, the development of the measuring method to be more simple, portable and inexpensive method was considered. The results obtained from this study were considered to be important basic information for the application to the sophisticated technique as the micro total analysis system or the lab‐on‐chip. Therefore, in further study, the micro‐electro‐mechanical system that facilitates accurate and economic analysis of a sample to be tested for practical use in the real market will be developed. We think that the microchip‐type oxygen sensor developed will become a powerful tool for the determination of total aerobic bacterial contamination in food industries as a rapid, simple and inexpensive measuring method.

Akriti Srivastava, Manjeet Harijan, Rajniti Prasad et al.

Journal of Molecular Recognition • 2024

Abstract Epitope imprinting has shown better prospects to synthesize synthetic receptors for proteins. Here, dual epitope imprinted polymer electrode (DEIP) matrix was fabricated on gold surface of electrochemical quartz crystal microbalance (EQCM) for recognition of target epitope sequence in blood samples of patients suffering from brain fever. Epitope sequences from outer membrane protein Por B of Neisseria meningitidis (MC58) bacteria predicted through immunoinformatic tools were chosen for imprinting. Self‐assembled monolayers (SAM) of cysteine appended epitope sequences on gold nanoparticles were subjected to polymerization prior to electrodeposition on gold coated EQCM electrode. The polymeric matrix was woven around the cysteine appended epitope SAMs through multiple monomers (3‐sulfo propyl methacrylate potassium salt (3‐SPMAP), benzyl methacrylate (BMA)) and crosslinker (N, N′‐methylene‐ bis ‐acrylamide). On extraction of the peptide sequences, imprinted cavities were able to selectively and specifically bind targeted epitope sequences in laboratory samples as well as ‘real’ samples of patients. Selectivity of sensor was examined through mismatched peptide sequences and certain plasma proteins also. The sensor was able to show specific binding towards the blood samples of infected patients, even in the presence of ‘matrix’ and other plasma proteins such as albumin and globulin. Even other peptide sequences, similar to epitope sequences only with one or two amino acid mismatches were also unable to show any binding. The analytical performance of DEIP‐EQCM sensor was tested through selectivity, specificity, matrix effect, detection limit (0.68–1.01 nM), quantification limit (2.05–3.05 nM) and reproducibility (RSD ~ 5%). Hence, a diagnostic tool for bacterium causing meningitis is successfully fabricated in a facile manner which will broaden the clinical access and make efficient population screening feasible.

C. A. Corcoran, R. K. Kobos

Biotechnology and Bioengineering • 1987

Abstract The feasibility of using specific enzyme and transport inhibitors to minimize the glutamine response of a potentiometric microbial sensor is demonstrated. The glutamine response of a bacterial electrode prepared with Escherichia coli as the biocatalyst in conjunction with an ammonia gas‐sensing electrode was greatly reduced by treating the electrode with the enzyme inhibitor 6‐diazo‐5‐oxo‐ L ‐norleucine (DONL) and the transport inhibitor γ‐ L ‐glutamylhydrazide. Each inhibitor effectively decreased glutamine response to a level sufficiently low to be considered negligible in clinical studies. Although the sensor ultimately recovered from the effects of a single exposure to an inhibitor, continuous exposure at an optimum concentration maintained a low response to glutamine. Furthermore, the treatment of the sensor with both inhibitors simultaneously resulted in a negligible response to glutamine of &lt;1 mV, indicating that both inhibitors are necessary for optimum inhibition of glutamine response. This approach is promising as a means of enhancing the selectivity of microbial sensors.

Maria del Carmen Jaramillo, Eduard Torrents, Rodrigo Martínez‐Duarte et al.

ELECTROPHORESIS • 2010

Abstract Dielectrophoresis (DEP) represents a powerful approach to manipulate and study living cells. Hitherto, several approaches have used 2‐D DEP chips. With the aim to increase sample volume, in this study we used a 3‐D carbon‐electrode DEP chip to trap and release bacterial cells. A continuous flow was used to plug an Escherichia coli cell suspension first, to retain cells by positive DEP, and thereafter to recover them by washing with peptone water washing solution. This approach allows one not only to analyze DEP behavior of living cells within the chip, but also to further recover fractions containing DEP‐trapped cells. Bacterial concentration and flow rate appeared as critical parameters influencing the separation capacity of the chip. Evidence is presented demonstrating that the setup developed in this study can be used to separate different types of bacterial cells.

Sun Ja Kim, T. H. Chung, S. H. Bae et al.

Applied Physics Letters • 2009

Bacterial inactivation experiment was performed using atmospheric pressure microplasma jets driven by radio-frequency wave of 13.56 MHz and by low frequency wave of several kilohertz. With addition of a ground ring electrode, the discharge current, the optical emission intensities from reactive radicals, and the sterilization efficiency were enhanced significantly. When oxygen gas was added to helium at the flow rate of 5 SCCM, the sterilization efficiency was enhanced. From the survival curve of Escherichia coli, the primary role in the inactivation was played by reactive species with minor aid from heat, UV photons, charged particles, and electric fields.

Rong Liu, Lina Ma, Shu Huang et al.

New Journal of Chemistry • 2017

A polyaniline (PANI)/graphene (GN)/bacterial cellulose (BC) flexible and freestanding supercapacitor electrode is synthesized via a facile chemical polymerization and filtering method.

G. A. Rechnitz, T. L. Riechel, R. K. Kobos et al.

Science • 1978

A novel bioselective membrane electrode for L-glutamine has been constructed by coupling living bacteria of the strain Sarcina flava to a potentiometric ammonia gas sensor. Tests in aqueous standards and human serum show that the electrode combines excellent sensitivity and selectivity with rapid response and a useful lifetime of at least 2 weeks.