Tomos G. A. A. Harris, N. Heidary, S. Frielingsdorf et al.

ChemElectroChem • 2021

21 22 23 29 33 39 41 42 43 45 46 47 48 49 50 51 52 53 54 55 56 57 In this work, we demonstrate that diazonium electrografting of biocompatible interfaces on transparent conducting oxide indium tin oxide (ITO) can be controlled and optimized to achieve low charge transfer resistance, allowing highly efficient electron transfer to an immobilized model enzyme, the oxygen-tolerant [NiFe]-hydrogenase from Ralstonia eutropha. The use of a radical scavenger enables control of the interface thickness, and thus facilitates maximization of direct electron transfer processes between the enzyme’s active center and the electrode. Using this approach, amine and carboxylic acid functionalities were grafted on ITO, allowing enzyme immobilization both under moderate electrostatic control and covalently via amide bond formation. Despite an initial decrease in catalytic activity, covalent immobilization led to an improve-ment in current stability compared to just electrostatically immobilized enzyme. Given the superior stability of electrografted interfaces in comparison to adsorbed or self-assembled interfaces, we propose electrografting as an alternative approach for the functional immobilization of redox-active enzymes on transparent conducting oxide (TCO) electrodes in bioelectronic devices. distance from sample holder to sputter source of 75 mm. An Argon/oxygen atmosphere of 30:1 was used and the power of the RF was 200 W. A PTFE-coated O-ring was used to seal the electrochemical cell on top of the coated prism, forming a working electrode with a geometric surface area of 0.79 cm 2 in contact with the electrolyte. IR Spectra were recorded between 4000 and 1000 cm (cid:0) 1 with a spectral resolution of 4 cm (cid:0) 1 on a Bruker IFS66v/s spectrometer equipped with a liquid N 2 -cooled, photoconductive Mercury Cadmium Telluride detector. A temperature-controlled, homemade spectroelectrochemical cell was used at a controlled temperature of 25 ° C. 400 scans were averaged per IR spectrum.

P. Buzzetti, P. Blanchard, E. Girotto et al.

Chemical Communications • 2021

A series of polycyclic aromatics, naphthalene, phenanthrene, perylene, pyrene, 1-pyrenebutyric acid N-hydroxysuccinimide ester (pyrene NHS) and coronene, were immobilized via π stacking on carbon nanotube (CNT) electrodes and electro-oxidized in aqueous solutions. The obtained quinones were characterized and evaluated for the mediated electron transfer with FAD dependent glucose dehydrogenase during catalytic glucose oxidation.

Y. Lee, Mengwei Yuan, Rong Cai et al.

ACS Catalysis • 2020

Nitrogenase is the only biological catalyst that is known to be able to convert nitrogen gas to ammonia. In microorganisms, the MoFe catalytic protein of nitrogenase is reduced by a transient Fe pr...

Mizue Wanibuchi, Y. Kitazumi, O. Shirai et al.

Electrochemistry • 2021

The simulation model of the direct electron transfer (DET)-type bioelectrocatalysis at a porous electrode indicates that the catalytic current is proportional to the real surface area ( A ), when A is small. When A is large, the catalytic current is saturated at a limited value controlled by the mass transfer in the porous structure. In this study, the bioelectrocatalytic currents at porous electrodes are analyzed based on their charging currents. Comparisons among the carbon composites constructed with Vulcan and exfoliated graphite (JSP) show that the interface between the Vulcan and JSP particles is more suitable for the DET-type bioelectrocatalysis of bilirubin oxidase (BOD) than that between the particles of the same type. In particular, the most suitable properties were achieved at a Vulcan : JSP ratio of 1 : 1 in the composite electrode. In these composites, the multipoint contact between the BOD molecule and electrode seems to result in a higher DET-type bioelectrocatalytic activity.

Trevor D. Rapson, C. Gregg, R. Allen et al.

ChemSusChem • 2020

There is a growing interest in using ammonia as a liquid carrier of hydrogen for energy applications. Currently, ammonia is produced industrially by the Haber-Bosch process, which requires high temperature and high pressure. In contrast, bacteria have naturally evolved an enzyme known as nitrogenase, that is capable of producing ammonia and hydrogen at ambient temperature and pressure. Therefore, nitrogenases are attractive as a potentially more efficient means to produce ammonia via harnessing the unique properties of this enzyme. In recent years, exciting progress has been made in bioelectrocatalysis using nitrogenases to produce ammonia. Here, we outline the prospects for developing biological ammonia production, highlight the key advances in bioelectrocatalysis by nitrogenases and discuss possible solutions to the obstacles faced in realising this goal.

Xiaobo Liu, Xiaobin Yu

ACS Energy Letters • 2020

Butanol from renewable biomass is a promising advanced biofuel that can be used as an optimal substitute for gasoline in the transportation sectors, and therefore, large-scale industrial production...

M. Komkova, Alexei K Orlov, Andrei A. Galushin et al.

Analytical Chemistry • 2021

Catalytic current of pyrroloquinoline quinone (PQQ)-glucose dehydrogenase (PQQ-GDH) immobilized over electropolymerized methylene green (MG) is increased only five times after the addition of the freely diffusing mediator. This value, being an efficiency criterion for bioelectrocatalysis, is several (three to six) times lower than that for the best reagentless glucose electrodes reported for this enzyme. Thermodynamics of the polyMG|PQQ-GDH electrode is determined by the enzyme-catalyzed reaction pointing to the direct bioelectrocatalysis. PQQ-GDH immobilized over polyMG displays the current plateau region from 0.0 to 0.2 V in the presence of glucose; at 0.00 V, being the optimal potential for biosensing applications, the catalytic current of the polyMG|PQQ-GDH electrode is 700-fold higher than that for the enzyme on a blank electrode. Successful glucose detection in human sweat by means of the corresponding enzyme electrode confirms that the reported bioelectrocatalytic system is attractive for advanced biosensors, as well as for biofuel cells.

Koun Lim, Y. Lee, Olja Simoska et al.

ACS Applied Materials & Interfaces • 2021

Over the past two decades, the designs of redox polymers have become critical to the field of mediated bioelectrocatalysis and are used in commercial glucose biosensors, as well as other bioelectrochemical applications (e.g., energy harvesting). These polymers are specifically used to immobilize redox mediators on electrode surfaces, allowing for self-exchange-based conduction of electrons from enzymes far from the electrode to the electrode surface. However, the synthesis of redox polymers is challenging and results in large batch-to-batch variability. Herein, we report a rapid entrapment of mediators for NAD+-dependent bioelectrocatalysis within reverse ionically condensed polyelectrolytes. A high ionic strength aqueous solution of oppositely charged polyelectrolytes, composed of cationic polyguanidinium (PG) chloride and anionic sodium hexametaphosphate (P6), undergoes phase inversion into a solid microporous polyelectrolyte complex (PEC) when introduced into a low ionic strength aqueous solution. The ionic strength-triggered phase inversion of PGP6 solutions was investigated as a means to entrap mediators on the surface of electrodes for mediated bioelectrocatalysis. Compared to the traditional cross-linked immobilizations using redox polymers, this phase inversion takes place within seconds and requires up to 60 min for complete stabilization. In this work, redox mediator phenazine ethosulfate (PES) was entrapped within PGP6 on electrode surfaces for nicotinamide adenine dinucleotide (NAD+)-dependent bioelectrocatalysis. In the bulk solution, NAD+-dependent dehydrogenase enzymes catalyze the oxidation of the substrate while reducing NAD to reduced nicotinamide adenine dinucleotide (NADH). The resulting NADH is reoxidized to NAD+ by the entrapped PES that gets reduced on the electrode, completing the NAD+-regeneration-based bioelectrocatalysis. To show the use of these new materials in an application, biofuel cells were evaluated using four different anodic enzyme systems (alcohol dehydrogenase, lactate hydrogenase, glycerol dehydrogenase, and glucose dehydrogenase).

Esther Edwardes Moore, Samuel J. Cobb, A. Coito et al.

• 2021

Significance Enzyme bioelectrochemistry concerns the integration of oxidoreductase enzymes into electrodes to enable and study the transfer of electrons between the solid-state material surface and the biological catalyst. To achieve higher enzyme loading, and hence greater current densities, high-surface-area strategies have been employed to immobilize enzymes, but these porous electrode architectures amplify the formation of local chemical gradients. Enzyme selectivity and activity is highly dependent on such changes in local environment, such as substrate concentration, pH, and electrolyte species concentration. Here, electrochemistry and computational techniques are applied to explore, and hence optimize, the local environment of the fuel-producing oxidoreductases, hydrogenase and formate dehydrogenase, within porous electrodes. Bioelectrochemistry employs an array of high-surface-area meso- and macroporous electrode architectures to increase protein loading and the electrochemical current response. While the local chemical environment has been studied in small-molecule and heterogenous electrocatalysis, conditions in enzyme electrochemistry are still commonly established based on bulk solution assays, without appropriate consideration of the nonequilibrium conditions of the confined electrode space. Here, we apply electrochemical and computational techniques to explore the local environment of fuel-producing oxidoreductases within porous electrode architectures. This improved understanding of the local environment enabled simple manipulation of the electrolyte solution by adjusting the bulk pH and buffer pKa to achieve an optimum local pH for maximal activity of the immobilized enzyme. When applied to macroporous inverse opal electrodes, the benefits of higher loading and increased mass transport were employed, and, consequently, the electrolyte adjusted to reach −8.0 mA ⋅ cm−2 for the H2 evolution reaction and −3.6 mA ⋅ cm−2 for the CO2 reduction reaction (CO2RR), demonstrating an 18-fold improvement on previously reported enzymatic CO2RR systems. This research emphasizes the critical importance of understanding the confined enzymatic chemical environment, thus expanding the known capabilities of enzyme bioelectrocatalysis. These considerations and insights can be directly applied to both bio(photo)electrochemical fuel and chemical synthesis, as well as enzymatic fuel cells, to significantly improve the fundamental understanding of the enzyme–electrode interface as well as device performance.

Taiki Makizuka, K. Sowa, O. Shirai et al.

Analytical Sciences • 2022

In enzyme-based biosensors, Ag+ eluted from the reference electrode inhibits the enzyme activity. Herein, to suppress the inhibition of bilirubin oxidase (BOD) by Ag+, kinetic analysis was used to examine the effect of Ag+ on the activity of BOD. It was confirmed that the addition of Ag+ decreased the bioelectrocatalytic activity of BOD. Atomic absorption spectroscopy (AAS) suggested that Ag+ was attached to BOD. Moreover, the changes in the visible absorption spectra after Ag+ addition showed that Ag+ was bound to the type I Cu sites in BOD. During oxygen reduction by BOD, the direct-electron-transfer-type bioelectrocatalytic current decreased after Ag+ was added. The decay of the catalytic current was evaluated using kinetic analysis (assuming a pseudo-first-order reaction). Based on the analysis, the inhibition of BOD was suppressed when the Ag+ concentration was below 0.1 µM. Referring to the solubility product of AgCl, Cl− at a concentration of 1 mM suppressed the inhibition of the enzymatic activity by 95%.

N. Karimian, P. Hashemi, A. Khanmohammadi et al.

Analytical and bioanalytical chemistry research • 2020

Bioelectrocatalysis is a phenomenon concerned with biological catalysts, which accelerate the electrochemical reactions. Bioelectrocatalysis has been widely explored by the research community in various directions. Enzymes can catalyze different chemical reactions in living organisms by enzymes as the most important biological catalysts. These enzymatic biocatalysts are commercially available and commonly called enzyme electrodes. Electron transfer between the active center of the enzyme and the electrode can be performed either by direct electron transfer (DET) or by means of mediators (i.e. mediated electron transfer (MET)), which are discussed in details in the presented review. Therefore, different strategies have been used to increase the efficiency and stability of bioelectrocatalysis. In this review, different strategies of the bioelectrode designs have been discussed and the application of the common bioelectrodes used in the biosensors have been presented in the various fields. Moreover, a summary of the research status in the applications of bioelectrocatalysis in biosensors and biofuel cells was provided.

Xiaoti Yang, Wenjie Wu, Xiling Chen et al.

Science Advances • 2022

Artificial metalloenzymes (ArMs) are commonly designed with protein scaffolds containing buried coordination pockets to achieve substrate specificity and product selectivity for homogeneous reactions. However, their reactivities toward heterogeneous transformations are limited because interfacial electron transfers are hampered by the backbone shells. Here, we introduce bacterial small laccase (SLAC) as a new protein scaffold for constructing ArMs to directly catalyze electrochemical transformations. We use molecular dynamics simulation, x-ray crystallography, spectroscopy, and computation to illustrate the scaffold-directed assembly of an oxo-bridged dicobalt motif on protein surface. The resulting ArM in aqueous phase catalyzes electrochemical water oxidation without mediators or electrode modifications. Mechanistic investigation reveals the role of SLAC scaffold in defining the four-electron transfer pathway from water to oxygen. Furthermore, we demonstrate that SLAC-based ArMs implemented with Ni2+, Mn2+, Ru3+, Pd2+, or Ir3+ also enable direct bioelectrocatalysis of water electrolysis. Our study provides a versatile and generalizable route to complement heterogeneous repertoire of ArMs for expanded applications.

Y. Lee, Koun Lim, S. Minteer

Annual Review of Physical Chemistry • 2021

Enzyme cascades are plentiful in nature, but they also have potential in artificial applications due to the possibility of using the target substrate in biofuel cells, electrosynthesis, and biosensors. Cascade reactions from enzymes or hybrid bioorganic catalyst systems exhibit extended substrate range, reaction depth, and increased overall performance. This review addresses the strategies of cascade biocatalysis and bioelectrocatalysis for (a) CO2 fixation, (b) high value-added product formation, (c) sustainable energy sources via deep oxidation, and (d) cascaded electrochemical enzymatic biosensors. These recent updates in the field provide fundamental concepts, designs of artificial electrocatalytic oxidation-reduction pathways (using a flexible setup involving organic catalysts and engineered enzymes), and advances in hybrid cascaded sensors for sensitive analyte detection. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 72 is April 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

A. Ruff, F. Conzuelo, W. Schuhmann

Nature Catalysis • 2019

Bioelectrocatalysis provides access to sustainable and highly efficient technological applications. However, several limitations related either to the intrinsic properties of the biocatalyst or to technical difficulties still hamper or even prevent the integration of such devices into technologically relevant large-scale processes. In this Review, we challenge the common viewpoint suggesting biology-based catalytic systems as a promising approach for the provision of sustainable stored energy and discuss the status of bioelectrocatalytic devices developed for energy conversion. In particular, we focus on two major research areas in the field, that is, H 2 -powered hydrogenase-based biofuel cells and biophotoelectrodes for solar energy harvesting. We identify the main limitations that have to be addressed to gain access to applied large-scale bio-based and bio-inspired advanced energy conversion systems. Moreover, we show recent examples and milestones that are paving the way towards potential realization of these technologies by overcoming existing limiting factors. Bioelectrocatalysis provides access to sustainable and highly efficient technological applications, but several limitations still prevent the large-scale integration of such devices. This Review discusses the current status of hydrogenase-based biofuel cells and biophotoelectrodes for solar energy harvesting.

Zhongjie Han, Fei Wu, Ping Yu et al.

Analytical Chemistry • 2022

Highly π-conjugated (hetero)cyclic molecules having delocalized orbitals and tunable charge mobilities are attractive redox relays for mediated bioelectrocatalysis in manifold applications. As rigid molecules, their dynamics within the soft but confined intraprotein space becomes the crucial determinant of the enzyme-mediator electron-tunneling efficiency. However, it is rarely investigated in designing the mediated interface with a particular biocatalyst (e.g., oxidoreductase), which remains an empirical but try-and-error process. Herein, we present the computer-aided exploration of interactions between a flavin-containing reductive synthase and structurally diverse π-extended (hetero)cyclic mediators to realize reversed bioelectrocatalytic oxidation at low overpotentials. Compared to ring-fused systems with unbroken molecular planarity, heteroatom-bridged cyclic, and rotatable conjugated structures (e.g., indophenols) can experience unusually large dynamic torsion under biased forces of hydrogen bonding with enzyme residues. This behavior led to fast intraprotein reorientation (<50 ps) that shortened the electron-tunneling distance from 12 to 9 Å. Meanwhile, the lowest unoccupied molecular orbital level upon molecular torsion was decreased by 0.5 eV to further promote electron abstraction from the reduced flavin cofactor. An efficient distant electron tunneling also obviated mediator transport through the substrate channel, thus avoiding competitive inhibition on enzyme kinetics to broaden the operating concentration range. The resulting bioelectrocatalytic interface enables low-potential biosensing of glutamate with improved selectivity. Our finding provides new structural insights into constructing efficient long-range heterogeneous charge transport with biomacromolecular catalysts.

Shize Zheng, Chenxi Zhang, P. Zhan et al.

Green Chemistry • 2025

The valorization of biomass derivatives into fine chemicals through the electro-enzymatic catalysis combination routes under green chemistry scopes has a promising prospect. However, bottlenecks including poor electron transfer efficiency between...

Tatsushi Yoshikawa, F. Makino, T. Miyata et al.

Chemical Communications • 2022

Tungsten-containing formate dehydrogenase from Methylorubrum extroquens AM1 (FoDH1)-a promising biocatalyst for the interconversion of carbon dioxide/formate and nicotine adenine dinucleotide (NAD+)/NADH redox couples-was investigated using structural biology and bioelectrochemistry. FoDH1 is reported to be an enzyme that can realize "direct electron transfer (DET)-type bioelectrocatalysis." However, its 3-D structure, electrode-active sites, and electron transfer (ET) pathways remain unclear. The ET pathways were investigated using structural information, electrostatic interactions between the electrode and the enzyme, and the differences in the substrates. Two electrode-active sites and multiple ET pathways in FoDH1 were discovered.

Lucia S. Ferraraccio, Donatella Di Lisa, L. Pastorino et al.

Analytical Chemistry • 2022

A simple procedure to incorporate enzymes (horseradish peroxidase, HRP, and lactate oxidase, LOx) within alginate hydrogels is reported with electrochemiluminescence (ECL) used to detect the enzymatic reactions with the corresponding substrates. First, HRP and LOx were successfully immobilized into CaCO3 microspheres, followed by the electrostatic layer-by-layer deposition of a nanoshell onto the microspheres, and finally by their dispersion into alginate solution. The as-prepared dispersion was drop cast onto the glassy carbon electrodes and cross-linked by the external and internal gelation methods using Ca2+ cations. The enzymes encapsulated within the alginate hydrogels were characterized using cyclic voltammetry and kinetic studies performed using ECL. The results showed that the enzymatic activity was significantly maintained as a result of the immobilization, with values of the apparent Michaelis–Menten constants estimated as 7.71 ± 0.62 and 8.41 ± 0.43 μM, for HRP and LOx, respectively. The proposed biosensors showed good stability and repeatability with an estimated limit of detection of 5.38 ± 0.05 and 0.50 ± 0.03 μM for hydrogen peroxide and lactic acid, respectively. The as-prepared enzymes encapsulated within the alginate hydrogels showed good stability up to 28 days from their preparation. The sensitivity and selectivity of the enzymes encapsulated within the alginate hydrogels were tested in real matrices (HRP, hydrogen peroxide, in contact lens solution; LOx, lactic acid in artificial sweat) showing the sensitivity of the ECL detection methods for the detection of hydrogen peroxide and lactic acid in real samples.

Wenjing Lian, Xinyu Zhang, Yongbin Han et al.

Polymers • 2025

The highly selective and sensitive determination of pesticide residues in food is critical for human health protection. Herein, the specific selectivity of molecularly imprinted polymers (MIPs) was proposed to construct an electrochemical sensor for the detection of carbendazim (CBD), one of the famous broad-spectrum fungicides, by combining with the synergistic effect of bioelectrocatalysis and nanocomposites. Gold nanoparticle-reduced graphene oxide (AuNP-rGO) composites were electrodeposited on a polished glassy carbon electrode (GCE). Then the MIP films were electropolymerized on the surface of the nanolayer using CBD as the template molecule and o-phenylenediamine (OPD) as the monomer. The detection sensitivity of CBD on the heterogeneous structure films was greatly amplified by AuNP-rGO composites and the bioelectrochemical oxidation of glucose, which was catalyzed by glucose oxidase (GOD) with the help of mediator in the underlying solution. The developed sensor showed high selectivity, good reproducibility, and excellent stability towards CBD with the linear range from 2.0 × 10−9 to 7.0 × 10−5 M, and the limit of detection (LOD) of 0.68 nM (S/N = 3). The expected system would provide a new idea for the development of simple and sensitive molecularly imprinted electrochemical sensors (MIESs).

Hyeryeong Lee, S. Reginald, I. Chang

Advanced Materials Technologies • 2023

Due to the outstanding attributes of oxidoreductases, they have been utilized as biomaterials for bioelectrocatalytic systems. Herein, a simple and versatile biosynthetic approach that can designate binding position of enzymes on electrode with their surface‐orientation is suggested. In this regard, material‐selective properties of gold‐binding peptide (GBP) are exploited and genetically fused GBP to enzyme. To optimize the design of synthetic enzyme, a variable repeat number of GBP are fused to flavin adenine dinucleotide‐dependent glucose dehydrogenase gamma‐alpha complex (GDHγα) and their catalytic and gold‐binding activities are determined. The substrate catalysis and direct electrocatalytic capability of selected construct, GDHγα with three GBP repeats (GDHγα‐3GBP), are investigated on electrode. In an inorganic‐binding characterization, GDHγα‐3GBP exhibits fourfold higher affinity on gold (Au) surface and 215‐fold lower binding affinity for silicon dioxide (SiO2) than wild‐type GDHγα. Utilizing those regioselective features, fusion GDHγα is incorporated into nanotemplates comprising Au nanopatterns and SiO2 background. Thereby, nanoscale patterned GDHγα‐3GBP molecules are successfully obtained with their binding locations controlled specifically by Au nanopatterns, not SiO2. The results reveal that genetic SBP fusions enable highly selective template‐based surface assembly of biomolecules with electrically intimate cofactor‐surface interfaces. The proposed technology has remarkable potential to fabricate small‐scale biochips applied for enzyme‐based bioelectronics.

A. Abdullatypov, P. Oskin, V. Fedina et al.

Nanomaterials • 2023

This study was carried out in order to assess several modifications of carbon nanotube-based nanomaterials for their applications in laccase electrodes and model biofuel cells. The modified MWCNTs served as adapters for the immobilization of laccase from Catenuloplanes japonicus VKM Ac-875 on the surface of electrodes made of graphite rods and graphite paste. The electrochemical properties of the electrodes were tested in linear and cyclic voltammetrical measurements for the determination of the redox potential of the enzyme and achievable current densities. The redox potential of the enzyme was above 500 mV versus NHE, while the highest current densities reached hundreds of µA/cm2. Model biofuel cells on the base of the laccase cathodes had maximal power values from 0.4 to 2 µW. The possibility of practical application of such BFCs was discussed.

Jianqi Ye, Jinhua Lu, D. Wen

Materials Chemistry Frontiers • 2023

The growing energy demands and the boost in portable or implantable electronic devices have initiated substantial interest in enzymatic biofuel cells (EBFCs). Exploiting novel electrode materials is essential in promoting...

M. Fadeev, Gilad Davidson‐Rozenfeld, Zhenzhen Li et al.

ACS Applied Materials &amp; Interfaces • 2023

The assembly of enzyme [glucose oxidase (GOx)]-loaded stimuli-responsive DNA-based hydrogels on electrode surfaces, and the triggered control over the stiffness of the hydrogels, provides a means to switch the bioelectrocatalytic functions of the hydrogels. One system includes the assembly of GOx-loaded, pH-responsive, hydrogel matrices cross-linked by two cooperative nucleic acid motives comprising permanent duplex nucleic acids and “caged” i-motif pH-responsive duplexes. Bioelectrocatalyzed oxidation of glucose leads to the formation of gluconic acid that acidifies the hydrogel resulting in the separation of the i-motif constituents and lowering the hydrogel stiffness. Loading of the hydrogel matrices with insulin results in the potential-triggered, glucose concentration-controlled, switchable release of insulin from the hydrogel-modified electrodes. The switchable bioelectrocatalyzed release of insulin is demonstrated in the presence of ferrocenemethanol as a diffusional electron mediator or by applying an electrically wired integrated matrix that includes ferrocenyl-modified GOx embedded in the hydrogel. The second GOx-loaded, stimuli-responsive, DNA-based hydrogel matrix associated with the electrode includes a polyacrylamide hydrogel cooperatively cross-linked by duplex nucleic acids and “caged” G-quadruplex-responsive duplexes. The hydrogel matrix undergoes K+-ions/crown ether-triggered stiffness changes by the cyclic K+-ion-stimulated formation of G-quadruplexes (lower stiffness) and the crown ether-induced separation of the G-quadruplexes (higher stiffness). The hydrogel matrices demonstrate switchable bioelectrocatalytic functions guided by the stiffness properties of the hydrogels.

Jiamin Huang, Yang Gao, Yanhong Chang et al.

Advanced Science • 2023

At present, the global energy crisis and environmental pollution coexist, and the demand for sustainable clean energy has been highly concerned. Bioelectrocatalysis that combines the benefits of biocatalysis and electrocatalysis produces high‐value chemicals, clean biofuel, and biodegradable new materials. It has been applied in biosensors, biofuel cells, and bioelectrosynthesis. However, there are certain flaws in the application process of bioelectrocatalysis, such as low accuracy/efficiency, poor stability, and limited experimental conditions. These issues can possibly be solved using machine learning (ML) in recent reports although the combination of them is still not mature. To summarize the progress of ML in bioelectrocatalysis, this paper first introduces the modeling process of ML, then focuses on the reports of ML in bioelectrocatalysis, and ultimately makes a summary and outlook about current issues and future directions. It is believed that there is plenty of scope for this interdisciplinary research direction.

Hui Chen, Olja Simoska, Koun Lim et al.

Chemical Reviews • 2020

Bioelectrocatalysis is an interdisciplinary research field combining biocatalysis and electrocatalysis via the utilization of materials derived from biological systems as catalysts to catalyze the redox reactions occurring at an electrode. Bioelectrocatalysis synergistically couples the merits of both biocatalysis and electrocatalysis. The advantages of biocatalysis include high activity, high selectivity, wide substrate scope, and mild reaction conditions. The advantages of electrocatalysis include the possible utilization of renewable electricity as an electron source and high energy conversion efficiency. These properties are integrated to achieve selective biosensing, efficient energy conversion, and the production of diverse products. This review seeks to systematically and comprehensively detail the fundamentals, analyze the existing problems, summarize the development status and applications, and look toward the future development directions of bioelectrocatalysis. First, the structure, function, and modification of bioelectrocatalysts are discussed. Second, the essentials of bioelectrocatalytic systems, including electron transfer mechanisms, electrode materials, and reaction medium, are described. Third, the application of bioelectrocatalysis in the fields of biosensors, fuel cells, solar cells, catalytic mechanism studies, and bioelectrosyntheses of high-value chemicals are systematically summarized. Finally, future developments and a perspective on bioelectrocatalysis are suggested.

Aiko Kurimoto, S. A. Nasseri, Camden Hunt et al.

Nature Communications • 2023

Enzyme catalysis is used to generate approximately 50,000 tons of value-added chemical products per year. Nearly a quarter of this production requires a stoichiometric cofactor such as NAD^+/NADH. Given that NADH is expensive, it would be beneficial to regenerate it in a way that does not interfere with the enzymatic reaction. Water electrolysis could provide the proton and electron equivalent necessary to electrocatalytically convert NAD^+ to NADH. However, this form of electrocatalytic NADH regeneration is challenged by the formation of inactive NAD_2 dimers, the use of high overpotentials or mediators, and the long-term electrochemical instability of the enzyme during electrolysis. Here, we show a means of overcoming these challenges by using a bioelectrocatalytic palladium membrane reactor for electrochemical NADH regeneration from NAD^+. This achievement is possible because the membrane reactor regenerates NADH through reaction of hydride with NAD^+ in a compartment separated from the electrolysis compartment by a hydrogen-permselective Pd membrane. This separation of the enzymatic and electrolytic processes bypasses radical-induced NAD^+ degradation and enables the operator to optimize conditions for the enzymatic reaction independent of the water electrolysis. This architecture, which mechanistic studies reveal utilizes hydride sourced from water, provides an opportunity for enzyme catalysis to be driven by clean electricity where the major waste product is oxygen gas. Enzymatic catalysis requires cofactors such as NAD(P)H, whose regeneration is currently accomplished via secondary enzymes or electrolytic cell. Here, the authors report an electrochemical method of cofactors regeneration without supporting enzymes or mediators, nor formation of NAD_2 dimers.

Xiaohai Wang, Zhuanzhuan Shi, Zhikai Wang et al.

Materials • 2024

The microbial hybrid system modified by magnetic nanomaterials can enhance the interfacial electron transfer and energy conversion under the stimulation of a magnetic field. However, the bioelectrocatalytic performance of a hybrid system still needs to be improved, and the mechanism of magnetic field-induced bioelectrocatalytic enhancements is still unclear. In this work, γ-Fe2O3 magnetic nanoparticles were coated on a Shewanella putrefaciens CN32 cell surface and followed by placing in an electromagnetic field. The results showed that the electromagnetic field can greatly boost the extracellular electron transfer, and the oxidation peak current of CN32@γ-Fe2O3 increased to 2.24 times under an electromagnetic field. The enhancement mechanism is mainly due to the fact that the surface modified microorganism provides an elevated contact area for the high microbial catalytic activity of the outer cell membrane’s cytochrome, while the magnetic nanoparticles provide a networked interface between the cytoplasm and the outer membrane for boosting the fast multidimensional electron transport path in the magnetic field. This work sheds fresh scientific light on the rational design of magnetic-field-coupled electroactive microorganisms and the fundamentals of an optimal interfacial structure for a fast electron transfer process toward an efficient bioenergy conversion.

Yonatan Chemla, Federico Kaufman, M. Amiram et al.

Chemical Reviews • 2024

Genetic code expansion is a promising genetic engineering technology that incorporates noncanonical amino acids into proteins alongside the natural set of 20 amino acids. This enables the precise encoding of non-natural chemical groups in proteins. This review focuses on the applications of genetic code expansion in bioelectrocatalysis and biomaterials. In bioelectrocatalysis, this technique enhances the efficiency and selectivity of bioelectrocatalysts for use in sensors, biofuel cells, and enzymatic electrodes. In biomaterials, incorporating non-natural chemical groups into protein-based polymers facilitates the modification, fine-tuning, or the engineering of new biomaterial properties. The review provides an overview of relevant technologies, discusses applications, and highlights achievements, challenges, and prospects in these fields.

Elena E. Ferapontova

Electroanalysis • 2004

Abstract The role of the electrode material in the efficiency of direct (non‐mediated) bioelectrocatalytic reduction of H 2 O 2 catalyzed by horseradish peroxidase (HRP) is studied and discussed. The variations in direct peroxidase bioelectrocatalysis when coming from carbon/graphite to metal electrodes and oxides, as well as modified electrodes, are analyzed regarding the variations in adsorption/orientation of peroxidase at the electrodes, interfacial electron transfer rates and mechanism of catalysis.

Pengbo Wan, Xiaodong Chen

ChemElectroChem • 2014

Abstract Inspired by natural biochemical promotion and inhibition of electron‐transport processes in response to real‐life physical/chemical stimuli, artificial signal‐triggered bioelectrocatalysis and modulation of the electron‐transfer processes of redox biomolecules are vitally important for understanding electron‐transport pathways in bioelectrochemical systems and for mimicking the dynamic properties of sensitive biochemical reactions in real bioprocesses. Recently, the reversible activation and deactivation of bioelectrocatalysis by external stimuli on functional electrodes integrated with redox enzymes has been established, especially at stimuli‐responsive supramolecular interfaces. Potential applications in various research fields include controllable biofuel cells, bioelectronic devices, stimuli‐responsive biosensors, energy transduction, information storage, and data processing. This Minireview aims to summarize the current state‐of‐the‐art knowledge on various controllable bioelectrocatalysts from diverse functional interfaces formed by supramolecular interactions and supramolecular assemblies. The role of the assembled interface is highlighted, and the electrochemical kinetics during “on” and “off” states of bioelectrocatalysis is discussed. Finally, possible strategies for the future design of stimuli‐responsive bioelectrocatalysts integrated with multifunctional supramolecular interfaces are presented.

Kenji Kano

Bioscience, Biotechnology, and Biochemistry • 2022

ABSTRACT Redox enzymes can work as efficient electrocatalysts. The coupling of redox enzymatic reactions with electrode reactions is called enzymatic bioelectrocatalysis, which imparts high reaction specificity to electrode reactions with nonspecific characteristics. The key factors required for bioelectrocatalysis are hydride ion/electron transfer characteristics and low specificity for either substrate in redox enzymes. Several theoretical features of steady-state responses are introduced to understand bioelectrocatalysis and to extend the performance of bioelectrocatalytic systems. Applications of the coupling concept to bioelectrochemical devices are also summarized with emphasis on the achievements recorded in the research group of the author.

Taiki Adachi, Yuki Kitazumi, Osamu Shirai et al.

Preprints.org • 2020

Direct electron transfer (DET)-type bioelectrocatalysis, which couples electrode reactions and catalytic functions of redox enzymes without any redox mediator, is one of the most intriguing subjects studied over the past decades in the field of bioelectrochemistry. In order to realize the DET-type bioelectrocatalysis and to improve the performance, nanostructures of the electrode surface have to be carefully tuned for each enzyme. In addition, enzymes can also be tuned by protein engineering approach for the DET-type reaction. This review summarizes the resent progresses in this field of the research, while taking into consideration of the importance of nanostructure of electrodes as well as redox enzymes. Described are basic concepts and theoretical aspects of DET-type bioelectrocatalysis, significance of nanostructures as scaffolds for DET-type reactions, protein engineering approached for DET-type reactions, and concepts and facts of bidirectional DET-type reactions, from a cross-disciplinary viewpoint.

Taiki Adachi, Yuki Kitazumi, Osamu Shirai et al.

Preprints.org • 2020

Bioelectrocatalysis has become one of important research fields in electrochemistry and provided a firm base for an important technology for application to various bioelectrochemical devices such as biosensors, biofuel cells, and biosupercapacitors. The understanding and technology in bioelectrocatalysis have been greatly improved by introducing nanostructured electrode materials and protein-engineering methods over the last few decades. Recently, the electro-enzymatic production of renewable energy resources and useful organic compounds (bioelectrosynthesis) also attracts worldwide attention. In this review, we summarize recent progress in applications of enzymatic bioelectrocatalysis.

Taiki Adachi, Yuki Kitazumi, Osamu Shirai et al.

Preprints.org • 2020

Bioelectrocatalysis provides the intrinsic catalytic-functions of redox enzymes to non-specific electrode reactions and is the most important and basic concept for biosensors. This review starts by describing fundamental characteristics of bioelectrocatalytic reactions in mediated and direct electron transfer types from a theoretical viewpoint and summarizes amperometric biosensors based on multi-enzymatic cascades and for multi-analyte detection. The review also introduces prospective aspects of two new concepts of biosensors: mass-transfer-controlled (pseudo)steady-state amperometry at microelectrodes with enhanced enzymatic activity without calibration curves and potentiometric coulometry at enzyme/mediator-immobilized biosensors for absolute determination.

Elisabeth Lojou, Xinxin Xiao

Catalysts • 2021

Enzymatic bioelectrocatalysis relies on immobilizing oxidoreductases on electrode surfaces, leading to different applications, such as biosensors [...]

J. Connolly

JAMA: The Journal of the American Medical Association • 1982

This book represents the authors' provocative insights from decades of research into bioelectric effects. It begins with a historical but lively account of past research seeking to discover the vital animal or electrical forces distinguishing the living from the nonliving. Galvani's erroneous conclusions regarding animal electricity in 1786 were opportunistically diverted by Volta and others from the biologic realm into the technology of generating electricity. The discovery of voltaic electricity led to the battery-operated telegraph, the arc light, and, ultimately, to the major dominance of electricity in today's society. The difficult questions pertaining to electricity's role in complex living forms remained unanswered. Biochemical explanations of biologic control systems dominated. Any suggestion of electrical control systems within the body was promptly equated with "vital force" research and dismissed as unscientific. Current concepts of electrobiologic controls owe more to developments in solid state physics than to biologic research. Body functions for which

A. Rusanov, I. Roy, O. Rusanova

Physiotherapy Quarterly • 2019

Introduction. Prognostic indices of orthopaedic implications development were investigated among patients with anterior cruciate ligament (ACL) injuries on the basis of stabilography research during the functional period of rehabilitation. Methods. The study included 52 randomly selected individuals with a complete ACL tear qualified for surgical reconstruction. The patients’ age was 18–59 (average: 37.8 ± 2.0) years. All participants underwent rehabilitation treatment in the institute of Traumatology and orthopaedics, National Academy of Medical Sciences of Ukraine, and had surgeries in the institute’s clinics. The crural part of the graft was fixed with the assistance of either the RigidFix system or the Cross-Pin system, and the Biointrafix or Biosure Sync system was applied for the tibial part. Results and conclusions. on the basis of the performed analysis of indices that characterize the functional condition of the injured limb of patients with an injury of ACL of knee joint at the functional stage of rehabilitation treatment, it is possible to identify a high and medium level of loading asymmetry in the lower extremities, decrease of electrobiological activity and muscle resistance ability during bending, stretching, adduction, and abduction, as the main prognostic criterion of orthopaedic complications development.

Wei Song, Huanhuan Li, Ting Guo et al.

Suicide and Life-Threatening Behavior • 2018

OBJECTIVE The present study aimed to explore the electrophysiological correlates involved in three-dimensional psychological pain and their relationship with suicide in patients with major depressive disorder. METHOD The sample comprised 23 and nine patients with major depressive disorder with high and low risk for suicide, respectively, and 24 healthy controls. All participants completed the measurements and performed an event-related potential-based analogue of the affective incentive delay task. The event-related potential components previously associated with motivationally salient cue (contingent negative variation, P2, and cue-P3), target (target-P3), and feedback (reward vs. punishment, feedback-related negativity, and feedback-P3) stimuli were examined. RESULTS All inventory scores differed significantly among the high-risk, low-risk, and healthy control groups. During the expectant phase, the main effect of group and interaction between group and condition was significant in the average amplitudes of the cue-P2 component. During the feedback phase, the feedback-P3 elicited by positive feedback had a significant main effect of group and of the interaction between group and condition. Specifically, the feedback-P3 elicited by negative feedback in the punitive condition showed significant positive correlations with the total and subscale scores on the Three-Dimensional Psychological Pain Scale. CONCLUSIONS Feedback-P3 may be an electrobiological component underlying the processing of psychological pain in suicidality.

Yunyun Huang, Jiaxuan Liang, Haotian Wu et al.

Light: Science &amp; Applications • 2025

Local microcurrent monitoring is of great significance for biological and battery systems, yet it poses a formidable challenge. The current measurement techniques rely on electromagnetic materials which inevitably introduce interference to the system under examination. To address this issue, a promising approach based on a dielectric fiber-optic sensor is demonstrated. The microfiber is capable of detecting microcurrent through monitoring the localized proton concentration signal with a pH resolution of 0.0052 pH units. By sensing the refractive index variation surrounding the sensor induced by the interaction between local proton concentration changes and oxidizer-treated microfiber surface through the evanescent field, this sensing mechanism effectively avoids the interference of the electromagnetic material on the performance of the tested system. This sensor exhibits a limit of detection for microcurrent of 1 μA. The sensing region is a microfiber with a diameter of 8.8 μm. It can get invaluable information that cannot be obtained through conventional electrochemical methods. Examples include photocurrent attenuation in photogenerated carrier materials during illumination, electrical activation in nerve cells, and fluctuations in the efficiency of electrical energy generation during battery discharge. This approach provides a powerful complement to electrochemical methods for the elucidation of microscale reaction mechanisms. The information provided by the prepared dielectric fiber-optic sensor will shed more light on proton kinetics and electrochemical and electrobiological mechanisms, which may fill an important gap in the current bioelectricity and battery monitoring methods.

G. Stanciu, M. Musteață, M. Armaşu et al.

Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Veterinary Medicine • 2015

Epilepsy is a chronic brain disease, of varied etiology, defined by the presence of the seizures of definite epileptic nature and by evolutional criteria, made of their tendencies to repeat in absence of triggering factors, known at variable intervals. The diagnosis of this disease is based on the clinical features and electrophysiology of the brain. Electroencephalogram (EEG) is the efficiently electrobiological test assessing the impact of epilepsy on activity of the brain.The aims of this study are to describe the interictal, intraictal and postictal parameters, and to evaluate the clinical usefulness of the EEG recording in dogs with idiopathic epilepsy, using induced sleep as activation method.EEG was performed on 27 dogs with idiopathic epilepsy. Electrical potentials acquisition was performed using the electroencephalograph Neurofax S, MEB 9400K Nihon Kohden. Before the test, all dogs were sedated with medetomidine hydrochloride 30 I¼g/kg inj. i.m. Stainless steel needle electrodes were subcutaneously placed, in an 8 channel bipolar montage, according to the model of Redding and Knecht (1984).The visual and quantitative analysis of the electroencephalographic tracks in idiopathic epilepsy revealed a background activity with a high instability and diversity of aspects, as there was more discordance between the electrical and clinical findings of the epilepsy. During interictal period, in incipient cases and onset of epilepsy, the EEG alterations were discrete, resuming to a couple of overvaulted peaks and ample lent theta waves on a normal background track. When epilepsy had a longer evolution, the background activity showed an intersection of slow waves with abnormally frequent waves, rich in epilpeptiform interictal discharges like: fast spike, slow waves, poly-spike and typical or atypical spike-wave complexes. The intraictal period was characterized by electrical crisis, suddenly appeared on all derivations, then intensified by neuronal recruiting phenomenon and in 2-3 seconds the EEG anomalies spread in all brain areas, as epilpeptiform discharges became bilateral synchronous. Postictal EEG was characterized by a much flattened aspect of the tracks, almost isoelectric.In conclusion, EEG gives valuable information about parameters and the severity of changes induced by epilepsy. EEG recorded using as an induced sleep activation method is the main way which proves the presence of an epileptic focus in the absence of clinical sings.