Bahaa A. Hemdan, Dipak A. Jadhav, Arup Kumar Dutta et al.

Journal of Water Process Engineering • 2023

Williane da Silva Freitas, Alessandra D’Epifanio, Carmelo Lo Vecchio et al.

Chemical Engineering Journal • 2023

Fe-N-C catalysts were synthesized by combining a Zn-based zeolitic imidazolate framework (ZIF-8) structure, adopted as a nitrogen-carbon template, with an iron salt and conductive carbon support followed by a thermal treatment. The effect of three different pyrolysis temperatures (700, 900, and 1000 °C) on Zn removal from ZIF-8 was investigated to enhance the formation of Fe-based moieties in the Nx-C groups during carbonization. Electrochemical characterization using a rotating ring disk electrode in an alkaline electrolyte demonstrated that ORR activity increased as the pyrolysis temperature increased. This trend can be ascribed to a more effective Zn removal and formation of high-active iron- and nitrogen-based catalytic sites, as pointed out by the Fe-N-C materials' chemical surface analysis after the pyrolysis step. The sample Fe-N-C-1000 demonstrated a remarkable ORR activity, even higher than Pt/C taken as reference. When subjected to accelerated stress tests, the Fe-N-C-1000 sample displayed higher performance durability over a long cycling duration (30,000 cycles) compared to Pt/C taken as control. Tests in the AEMFC fed with H2 showed that the performance of the Fe-N-C-1000 catalyst was competitive (OCV = 0.98 vs. 1.05 V, 149 vs. 148 mW cm−2) compared to the state-of-the-art Pt/C electrode, using a FUMASEP® FAA-3-50 membrane. The material found an application also in alkaline direct methanol fuel cell (ADMFC) fed with methanol solutions at high concentrations (up to 10 M) due to a high methanol tolerance, as pointed out by rotating disk electrode experiments.

Sai Kishore Ravi, Nikita Paul, Lakshmi Suresh et al.

Materials Horizons • 2019

Rhodobacter sphaeroides based photocapacitive novel touch-to-audio six-pixel tactile sensor that can pronounce the equivalent alphabet.

Dan Wu, Faqian Sun, Yan Zhou

Electrochimica Acta • 2017

Núbia Rodrigues, Sakae Yotsumoto Neto, Rita de Cássia Silva Luz et al.

Biosensors • 2018

A renewable, disposable, low cost, and sensitive sensor for the detection of organophosphorus pesticides was constructed by immobilizing the acetylcholinesterase enzyme (AChE), via glutaraldehyde, on magnetic iron nanoparticles (Fe₃O₄) previously synthesized and functionalized with chitosan (CS). The sensor was denoted AChE/CS/Fe₃O₄. The magnetic nanoparticles were characterized by Fourier transform infrared spectroscopy and transmission electron microscopy. Acetylthiocholine (ATCh) was incubated with AChE/CS/Fe₃O₄ and attached to a screen-printed electrode using a magnet. The oxidation of thiocholine (from ATCh hydrolysis) was monitored at an applied potential of +0.5 V vs. Ag/AgCl(KCl sat ) in 0.1 mol L -1 phosphate buffer solution (pH 7.5) as the supporting electrolyte. A mixture of the pesticide malathion and ATCh was investigated using the same procedure, and the results were compared and expressed as inhibition percentages. For determination of malathion, the proposed sensor presented a linear response in the range from 0.5 to 20 nmol L -1 (R = 0.9942). The limits of detection (LOD) and quantification (LOQ) were 0.3 and 0.8 nmol L -1 , respectively. Real samples were also investigated, with recovery values of 96.0% and 108.3% obtained for tomato and pond water samples, respectively. The proposed sensor is a feasible option for malathion detection, offering a linear response, good sensitivity, and a low detection limit.

Dong-Bum Seo, Tran Nam Trung, Dong-Ok Kim et al.

Nano-Micro Letters • 2020

A controllable approach that combines surface plasmon resonance and two-dimensional (2D) graphene/MoS 2 heterojunction has not been implemented despite its potential for efficient photoelectrochemical (PEC) water splitting. In this study, plasmonic Ag-decorated 2D MoS 2 nanosheets were vertically grown on graphene substrates in a practical large-scale manner through metalorganic chemical vapor deposition of MoS 2 and thermal evaporation of Ag. The plasmonic Ag-decorated MoS 2 nanosheets on graphene yielded up to 10 times higher photo-to-dark current ratio than MoS 2 nanosheets on indium tin oxide. The significantly enhanced PEC activity could be attributed to the synergetic effects of SPR and favorable graphene/2D MoS 2 heterojunction. Plasmonic Ag nanoparticles not only increased visible-light and near-infrared absorption of 2D MoS 2 , but also induced highly amplified local electric field intensity in 2D MoS 2 . In addition, the vertically aligned 2D MoS 2 on graphene acted as a desirable heterostructure for efficient separation and transportation of photo-generated carriers. This study provides a promising path for exploiting the full potential of 2D MoS 2 for practical large-scale and efficient PEC water-splitting applications.

Deepti Sharma, Jong‐Min Lee, Junyoung Seo et al.

Sensors • 2017

We developed a versatile and highly sensitive biosensor platform. The platform is based on electrochemical-enzymatic redox cycling induced by selective enzyme immobilization on nano-sized carbon interdigitated electrodes (IDEs) decorated with gold nanoparticles (AuNPs). Without resorting to sophisticated nanofabrication technologies, we used batch wafer-level carbon microelectromechanical systems (C-MEMS) processes to fabricate 3D carbon IDEs reproducibly, simply, and cost effectively. In addition, AuNPs were selectively electrodeposited on specific carbon nanoelectrodes; the high surface-to-volume ratio and fast electron transfer ability of AuNPs enhanced the electrochemical signal across these carbon IDEs. Gold nanoparticle characteristics such as size and morphology were reproducibly controlled by modulating the step-potential and time period in the electrodeposition processes. To detect cholesterol selectively using AuNP/carbon IDEs, cholesterol oxidase (ChOx) was selectively immobilized via the electrochemical reduction of the diazonium cation. The sensitivity of the AuNP/carbon IDE-based biosensor was ensured by efficient amplification of the redox mediators, ferricyanide and ferrocyanide, between selectively immobilized enzyme sites and both of the combs of AuNP/carbon IDEs. The presented AuNP/carbon IDE-based cholesterol biosensor exhibited a wide sensing range (0.005-10 mM) and high sensitivity (~993.91 µA mM -1 cm -2 ; limit of detection (LOD) ~1.28 µM). In addition, the proposed cholesterol biosensor was found to be highly selective for the cholesterol detection.

Alberto Bianco, Yuan Chen, Elżbieta Frąckowiak et al.

Carbon • 2020

Zheng Chen, Jian Li, Jing Zhang et al.

Journal of Cleaner Production • 2024

Yunlong He, Zhenye Kang, Jing Li et al.

Industrial Chemistry and Materials • 2023

This review discusses the OER reaction mechanism (AEM and LOM) and the research progress of MnO 2 -based OER catalysts. The optimization strategy of MnO 2 -based catalysts was summarized.

Xiang Li, Tingting Zhao, Xiaomin Hu et al.

Process Biochemistry • 2026

Fariza Ammam, Pier‐Luc Tremblay, Dawid Mariusz Lizak et al.

Biotechnology for Biofuels • 2016

This study presented here shows that optimization of microbial catalyst growth medium can improve productivity and lead to the biosynthesis of different products by gas fermentation and MES. It also provides insights on the metabolism of biofuels production in acetogens and demonstrates that S. ovata has an important untapped metabolic potential for the production of other chemicals than acetate via CO2-converting bioprocesses including MES.

Ling Wang, Mariko Ago, Maryam Borghei et al.

ACS Sustainable Chemistry & Engineering • 2019

We introduce an eco-friendly process to dramatically simplify carbon microfiber fabrication from biobased materials. The microfibers are first produced by wet-spinning in aqueous calcium chloride solution, which provides rapid coagulation of the hydrogel precursors comprising wood-derived lignin and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibrils (TOCNF). The thermomechanical performance of the obtained lignin/TOCNF filaments is investigated as a function of cellulose nanofibril orientation (wide angle X-ray scattering (WAXS)), morphology (scanning electron microscopy (SEM)), and density. Following direct carbonization of the filaments at 900 °C, carbon microfibers (CMFs) are obtained with remarkably high yield, up to 41%, at lignin loadings of 70 wt % in the precursor microfibers (compared to 23% yield for those produced in the absence of lignin). Without any thermal stabilization or graphitization steps, the morphology, strength, and flexibility of the CMFs are retained to a large degree compared to those of the respective precursors. The electrical conductivity of the CMFs reach values as high as 103 S cm -1 , making them suitable for microelectrodes, fiber-shaped supercapacitors, and wearable electronics. Overall, the cellulose nanofibrils act as structural elements for fast, inexpensive, and environmentally sound wet-spinning while lignin endows CMFs with high carbon yield and electrical conductivity.

Francisco Thálysson Tavares Cavalcante, Ítalo Rafael de Aguiar Falcão, José Erick da Silva Souza et al.

Electrochem • 2021

Among the many biological entities employed in the development of biosensors, enzymes have attracted the most attention. Nanotechnology has been fostering excellent prospects in the development of enzymatic biosensors, since enzyme immobilization onto conductive nanostructures can improve characteristics that are crucial in biosensor transduction, such as surface-to-volume ratio, signal response, selectivity, sensitivity, conductivity, and biocatalytic activity, among others. These and other advantages of nanomaterial-based enzymatic biosensors are discussed in this work via the compilation of several reports on their applications in different industrial segments. To provide detailed insights into the state of the art of this technology, all the relevant concepts around the topic are discussed, including the properties of enzymes, the mechanisms involved in their immobilization, and the application of different enzyme-derived biosensors and nanomaterials. Finally, there is a discussion around the pressing challenges in this technology, which will be useful for guiding the development of future research in the area.

Muhammad Bilal, ‪Damià Barceló, Hafiz M.N. Iqbal

The Science of The Total Environment • 2021

Valeria Agostino, Miriam A. Rosenbaum

Frontiers in Energy Research • 2018

Electroautotrophs are microbes able to perform different biocathodic reactions by using CO2 as sole carbon source and electrochemical reducing power as a sole energy source. Electroautotrophy has been discovered in several groups of microorganisms, including iron-oxidizing bacteria, iron-reducing bacteria, nitrate-reducing bacteria, acetogens, methanogens and sulfate-reducing bacteria. The high diversity of electroautrophs results in a wide range of Bioelectrochemical Systems (BES) applications, ranging from bioproduction to bioremediation. In the last decade, particular research attention has been devoted towards the discovery, characterization and application of acetogenic and methanogenic electroautotrophs. Less attention has been given to autotrophic sulfate-reducing microorganisms, which are extremely interesting biocatalysts for multiple BES technologies, with concomitant CO2 fixation. They can accomplish water sulfate removal, hydrogen production and, in some case, even biochemicals production. This mini-review gives a journey into electroautotrophic ability of sulfate-reducing bacteria and highlights their possible importance for biosustainable applications. More specifically, general metabolic features of autotrophic sulfate reducers are introduced. Recently discovered strains able to perform extracellular electron uptake and possible molecular mechanisms behind this electron transfer capacity are explored. Finally, BES technologies based on sulfate-reducing electroautotrophs are illustrated.

Noreen Fatima, Asif Jamal, Zaixing Huang et al.

Sustainability • 2021

Currently, conversion of coal into alternative fuel and non-fuel valuable products is in demand and growing interest. In the present study, humic acid was extracted from two different ranks of coal, i.e., low rank and high rank (lignite and bituminous), through chemical pretreatment by nitric acid. Samples of lignite and bituminous coal were subjected to nitric acid oxidation followed by extraction using KOH and NaOH gravimetric techniques. The chemical pretreatment of both types of coal led to enhanced yields of humic acid from 21.15% to 57.8% for lignite low-rank coal and 11.6% to 49.6% bituminous high rank coal. The derived humic acid from native coal and nitric acid treated coal was analyzed using elemental analysis, E4/E6 ratio of absorbance at 465 nm and 665 nm using UV-Visible spectrophotometry and Fourier transformed infrared spectroscopy FTIR. The chemical characteristics of coal treated with nitric acid have shown increased molecular weight and improved aromaticity with more oxygen and nitrogen and lower C, H, and sulphur content. The E4/E6 ratio of nitric acid-treated low and high ranks of coal was high. The FTIR spectroscopic data of nitric acid-treated lignite coal indicates an intensive peak of carboxyl group at 2981.84 cm−1, while bituminous coal was shown in cooperation with the N-H group at 2923.04 cm−1. SEM was performed to detect the morphological changes that happen after producing humic acid from HNO3 treatment and native coal. The humic acid produced from HNO3 treated coal had shown clear morphological changes and some deformations on the surface. SEM-EDS detected the major elements, such as nitrogen, in treated humic acid that were absent in raw coal humic acid. Hence, the produced humic acid through HNO3 oxidation showed a more significant number of humic materials with improved efficiency as compared to native coal. This obtained humic acid can be made bioactive for agriculture purposes, i.e., for soil enrichment and improvement in growth conditions of plants and development of green energy solutions.

Feng Li, Yuanxiu Li, Liming Sun et al.

Biotechnology for Biofuels • 2017

To the best of our knowledge, this was the first report on the rationally designed Shewanella that could use xylose as the sole carbon source and electron donor to produce electricity. The synthetic biology strategies developed in this study could be further extended to rationally engineer other exoelectrogens for lignocellulosic biomass utilization to generate electricity power.

Francesca Soavi, Luca Giacomo Bettini, P. Piseri et al.

Journal of Power Sources • 2016

Supercapacitors (SCs) are playing a key role for the development of self-powered and self-sustaining integrated systems for different fields ranging from remote sensing, robotics and medical devices. SC miniaturization and integration into more complex systems that include energy harvesters and functional devices are valuable strategies that address system autonomy. Here, we discuss about novel SC fabrication and integration approaches. Specifically, we report about the results of interdisciplinary activities on the development of thin, flexible SCs by an additive technology based on Supersonic Cluster Beam Deposition (SCBD) to be implemented into supercapacitive electrolyte gated transistors and supercapacitive microbial fuel cells. Such systems integrate at materials level the specific functions of devices, like electric switch or energy harvesting with the reversible energy storage capability. These studies might open new frontiers for the development and application of new multifunction-energy storage elements.

Maida Aysla Costa de Oliveira, Alessandra D’Epifanio, Hitoshi Ohnuki et al.

Catalysts • 2020

Scientific and technological innovation is increasingly playing a role for promoting the transition towards a circular economy and sustainable development. Thanks to its dual function of harvesting energy from waste and cleaning up waste from organic pollutants, microbial fuel cells (MFCs) provide a revolutionary answer to the global environmental challenges. Yet, one key factor that limits the implementation of larger scale MFCs is the high cost and low durability of current electrode materials, owing to the use of platinum at the cathode side. To address this issue, the scientific community has devoted its research efforts for identifying innovative and low cost materials and components to assemble lab-scale MFC prototypes, fed with wastewaters of different nature. This review work summarizes the state-of the-art of developing platinum group metal-free (PGM-free) catalysts for applications at the cathode side of MFCs. We address how different catalyst families boost oxygen reduction reaction (ORR) in neutral pH, as result of an interplay between surface chemistry and morphology on the efficiency of ORR active sites. We particularly review the properties, performance, and applicability of metal-free carbon-based materials, molecular catalysts based on metal macrocycles supported on carbon nanostructures, M-N-C catalysts activated via pyrolysis, metal oxide-based catalysts, and enzyme catalysts. We finally discuss recent progress on MFC cathode design, providing a guidance for improving cathode activity and stability under MFC operating conditions.

Takahiro Yamashita, Mitsuyoshi Ishida, Shiho Asakawa et al.

Biotechnology for Biofuels • 2016

This is the first demonstration of power generation using an FO-SSA in MFCs. Flame oxidation of the SSA enhances electricity production in MFCs, which is higher than that with the common carbonaceous electrode, CCA. The FO-SSA is not only inexpensive but also can be prepared using a simple method. To our knowledge, this study reveals, for the first time, that the predominant Geobacter species in the biofilm depends on the anode material. The high performance of the FO-SSA could result from the particularly high population of bacteria closely related to G. metallireducens in the biofilm.

Zari Tehrani, Simon Peter Whelan, A. Bernardus Mostert et al.

2D Materials • 2020

Abstract The application of highly sensitive pH sensors manufactured in volume at low cost has great commercial interest due to an extensive array of potential applications. Such areas include industrial processing, biotechnology and medical diagnostics particularly in the development of point of care (POC) devices. A novel printable electrochemical pH sensor based on graphene and pigment melanin (PGM), was designed and produced by using a screen printing process that enables up scaling for potential commercial application. We demonstrate a highly sensitive pH sensor (62 mV pH −1 ± 7) over a pH range from 5 to 8, with high stability and superior performance when compared with a number of existing devices and making it suitable for physiological applications.

Swee Su Lim, Jean‐Marie Fontmorin, Hai The Pham et al.

The Science of The Total Environment • 2021

Microbial fuel cells (MFCs) that simultaneously remove organic contaminants and recovering metals provide a potential route for industry to adopt clean technologies. In this work, two goals were set: to study the feasibility of zinc removal from industrial effluents using MFCs and to understand the removal process by using reaction rate models. The removal of Zn 2+ in MFC was over 96% for synthetic and industrial samples with initial Zn 2+ concentrations less than 2.0 mM after 22 h of operation. However, only 83 and 42% of the zinc recovered from synthetic and industrial samples, respectively, was attached on the cathode surface of the MFCs. The results marked the domination of electroprecipitation rather than the electrodeposition process in the industrial samples. Energy dispersive X-ray (EDX) analysis showed that the recovered compound contained not only Zn but also O, evidence that Zn(OH) 2 could be formed. The removal of Zn 2+ in the MFC followed a mechanism where oxygen was reduced to hydroxide before reacting with Zn 2+ . Nernst equations and rate law expressions were derived to understand the mechanism and used to estimate the Zn 2+ concentration and removal efficiency. The zero-, first- and second-order rate equations successfully fitted the data, predicted the final Zn 2+ removal efficiency, and suggested that possible mechanistic reactions occurred in the electrolysis cell (direct reduction), MFC (O 2 reduction), and control (chemisorption) modes. The half-life, t 1/2, of the Zn 2+ removal reaction using synthetic and industrial samples was estimated to be 7.0 and 2.7 h, respectively. The t 1/2 values of the controls (without the power input from the MFC bioanode) were much slower and were recorded as 21.5 and 7.3 h for synthetic and industrial samples, respectively. The study suggests that MFCs can act as a sustainable and environmentally friendly technology for heavy metal removal without electrical energy input or the addition of chemicals.

Lijing Di, Hua Yang, Tao Xian et al.

Nanomaterials • 2019

Z-scheme Ag₂S/BiFeO₃ heterojunction composites were successfully prepared through a precipitation method. The morphology and microstructure characterization demonstrate that Ag₂S nanoparticles (30⁻50 nm) are well-decorated on the surfaces of polyhedral BiFeO₃ particles (500⁻800 nm) to form Ag₂S/BiFeO₃ heterojunctions. The photocatalytic and photo-Fenton catalytic activities of the as-derived Ag₂S/BiFeO₃ heterojunction composites were evaluated by the degradation of methyl orange (MO) under visible-light irradiation. The photocatalytic result indicates that the Ag₂S/BiFeO₃ composites exhibit much improved photocatalytic activities when compared with bare Ag₂S and BiFeO₃. The optimum composite sample was observed to be 15% Ag₂S/BiFeO₃ with an Ag₂S mass fraction of 15%. Furthermore, the addition of H₂O₂ can further enhance the dye degradation efficiency, which is due to the synergistic effects of photo- and Fenton catalysis. The results of photoelectrochemical and photoluminescence measurements suggest a greater separation of the photoexcited electron/hole pairs in the Ag₂S/BiFeO₃ composites. According to the active species trapping experiments, the photocatalytic and photo-Fenton catalytic mechanisms of the Ag₂S/BiFeO₃ composites were proposed and discussed.

Fayaz Ali, Sher Bahadar Khan, Tahseen Kamal et al.

Scientific Reports • 2018

Different chitosan-titanium oxide (CS-TiO 2 -x, with x = TiO 2 loadings of 1, 5, 10,15 and 20 wt%) nanocomposite fibers were prepared and kept separately in each salt solution of CuSO 4 , CoNO 3 , AgNO 3 and NiSO 4 to adsorb Cu 2+ , Co 2+ , Ag + , and Ni + ions, respectively. The metal ions loaded onto CS-TiO 2 fibers were reduced to their respective zero-valent metal nanoparticles (ZV-MNPs) like Cu 0 , Co 0 , Ag 0 and Ni 0 by treating with NaBH 4 . The CS-TiO 2 fibers templated with various ZV-MNPs were characterized and investigated for their catalytic efficiency. Among all prepared ZV-MNPs, Cu 0 nanoparticles templated on CS-TiO 2 -15 fibers exhibited high catalytic efficiency for the reduction of dyes (methyl orange (MO), congo red (CR), methylene blue (MB) and acridine orange (AO)) and nitrophenols (4-nitrohphenol (4-NP), 2-nitrophenol (2-NP), 3-nitrophenol (3-NP) and 2,6-dinitrophenol (2,6-DNP)). Besides the good catalytic activities of Cu/CS-TiO 2 -15 fibers, it could be easily recovered by simply pulling the fiber from the reaction medium.

Lei Chen, Limin Jiang, Liangyue Cheng et al.

Chemosphere • 2024

Ming Huang, Bangwei Deng, Xiaoli Zhao et al.

ACS Nano • 2022

Although various single-atom catalysts have been designed, atomically engineering their coordination environment remains a great challenge. Herein, a one-pot template-sacrificing pyrolysis approach is developed to synthesize well-defined Ni-N 4 -O catalytic sites on highly porous graphitic carbon for electrocatalytic CO 2 reduction to CO with high Faradaic efficiency (maximum of 97.2%) in a wide potential window (-0.56 to -1.06 V vs RHE) and with high stability. In-depth experimental and theoretical studies reveal that the axial Ni-O coordination introduces asymmetry to the catalytic center, leading to lower Gibbs free energy for the rate-limiting step, strengthened binding with *COOH, and a weaker association with *CO. The present results demonstrate the successful atomic-level coordination environment engineering of high-surface-area porous graphitic carbon-supported Ni single-atom catalysts (SACs), and the demonstrated method can be applied to synthesize an array of SACs (metal-N 4 -O) for various catalysis applications.

Sergio J. Ponce-Jahen, Edgardo I. Valenzuela, J. Rene Rangel‐Mendez et al.

Bioresource Technology • 2024

This study investigates the potential of humic substances (HS) and graphene oxide (GO), as extracellular electron acceptors (EEA) for nitrification, aiming to explore alternatives to sustain this process in wastewater treatment systems. Experimental results demonstrate the conversion of ammonium to nitrate (up to 87 % of conversion) coupled to the reduction of either HS or GO by anaerobic consortia. Electron balance confirmed the contribution of HS and GO to ammonium oxidation. Tracer analysis in incubations performed with 15 NH 4 + demonstrated 15 NO 3 - as the main product with a minor fraction ending as 29 N 2 . Phylogenetic analysis identified Firmicutes, Euryarchaeota, and Chloroflexi as the microbial lineages potentially involved in anoxic nitrification linked to HS reduction. This study introduces a new avenue for research in which carbon-based materials with electron-accepting capacity may support the anoxic oxidation of ammonium, for instance in bioelectrochemical systems in which carbon-based anodes could support this novel process.

Rui Tang, Baocai Zhang, Longhai Dai et al.

ACS Sustainable Chemistry & Engineering • 2024

Converting cellulose and other widely distributed biomass resources into bioelectricity by exoelectrogen-based bioelectrochemical systems has been developed as a potential solution to the simultaneous environmental pollution treatment and power harvest. However, exoelectrogens are generally unable to utilize cellulose for cell growth and power generation due to a lack of relevant metabolic pathways and enzymes, which considerably limited practical applications. In this study, to use discarded cellulosic biomass from liquor industry as carbon source for power generation, we constructed an artificial three-species microbial consortium that included Trichoderma reesei, Lactobacillus pentosus, and Shewanella oneidensis. In this consortium, T. reesei digested cellulose into soluble sugars, which were then converted to lactate by L. pentosus, and S. oneidensis subsequently utilized lactate as the carbon source and electron donor to produce electricity. To enhance the energy conversion efficiency of this consortium, we first optimized the T. reesei–L. pentosus subconsortium, including the inoculum size and reaction temperature and pH, to increase degradation of cellulose and production of lactate, which led to an output power density of 40.39 mW/m2 by the artificial three-species microbial consortium. Second, to improve the extracellular electron transfer rate and biofilm formation of S. oneidensis, the flavin synthesis and extracellular polysaccharide accumulation were strengthened via overexpressing genes involved in the biosynthesis of flavin and extracellular polysaccharides, leading to an output power density of 453.52 mW/m2. Lastly, to enhance the thickness and conductivity of the electroactive biofilm, conductive materials (reduced graphene oxide and carbon nanotubes) were used to integrate with the engineered microbial consortium to form a 3D-assembled biohybrid, which dramatically enhanced the thickness and abundance of S. oneidensis in electroactive biofilm on the anode, thus achieving a maximum output power density of 816.93 mW/m2, 62.84-fold higher than that of the wild-type microbial consortium, which is, to the best our knowledge, the highest output power densities that have ever been reported in the genetically engineered microbial consortium using cellulosic biomass. This study lays a theoretical foundation for promoting circular carbon economy and realizing efficient utilization of biomass.

Hanna Cheropkina, Gianluca Catucci, Federico Cesano et al.

Bioelectrochemistry • 2022

Lingyu Meng, Li Xie, Yuu Hirose et al.

Biosensors and Bioelectronics • 2022

Genping Yi, Dan Cui, Liming Yang et al.

Environmental Research • 2020

Vinícius R. Gonçales, Rafael N. P. Colombo, Marco A. O. S. Minadeo et al.

Journal of Electroanalytical Chemistry • 2016

Xiuyun Wang, Qian Li, Jingjing Xu et al.

Analytical Chemistry • 2016

This study demonstrates a new strategy to develop in vivo electrochemical biosensors through rational design and simple formation of bioelectrochemically multifunctional film (BMF). The BMF is rationally designed by first efficiently incorporating oxidase, ferrocene mediator, and graphene oxide into polymaleimidostyrene/polystyrene (PMS/PS) matrix to form a homogeneous mixture and then simply formed by drop-coating the mixture onto solid conducting substrate. By using the as-formed BMF, electrochemical biosensors could be constructed with a technical simplicity and high reproducibility. To illustrate the BMF-based biosensors for in vivo applications, we directly couple the biosensors to in vivo microdialysis to establish an online electrochemical system (OECS) for in vivo monitoring of glucose in rat auditory cortex during salicylate-induced tinnitus model. The OECS with the BMF-based biosensor as the detector shows a linear response toward glucose within a concentration range from 50 to 500 μM with a detection limit of 10 μM (S/N = 3). Additionally, the OECS is stable and does not suffer from the interference from the electroactive species endogenously coexisting in the brain microdialysate. With the BMF-based OECS, the basal level of glucose in the microdialysate continuously sampled from rat auditory cortex is determined to be 120 ± 10 μM (n = 5). After the rats were administrated with salicylate to induce transient tinnitus, the microdialysate glucose concentration in the rat auditory cortex remarkably increased to 433 ± 190 μM (n = 5) at the time point of 1.5 h. This study essentially offers a new, technically simple and reproducible approach to development of in vivo electrochemical biosensors, which is envisaged to be relatively useful for understanding of the molecular basis of brain functions.

Mariela I. Lescano, Aurélien Gasnier, María L. Pedano et al.

RSC Advances • 2018

In this work, we report a simple and scalable method to produce high efficiency 3D graphene-based electrodes (GH) for bioelectrochemical systems. GH were obtained by self-assembly of graphene oxide, through slow reduction with ascorbic acid over conductive mesh-works (carbon cloth and stainless-steel). The GH structure and composition were characterised by electron microscopy (SEM) and spectroscopy (FTIR and Raman), whereas the electrodes' performance was tested by chronoamperometry and cyclic voltammetry in a microbial electrolysis cell (MEC) inoculated with a pure culture of G. sulfurreducens . The hydrogel had a broad pore size distribution (>1 μm), which allowed bacterial colonisation within the framework. The macro-porous structure and chemical properties of the hydrogel rendered a higher bacterial loading capacity and substrate oxidation rate than other carbonaceous materials, including different reported graphene electrodes, which significantly increased MEC performance.

Xiaomeng Ma, Jianwei Wang, Liting Zhao et al.

Analytical Chemistry • 2023

A novel microfiber-like biohydrogel was fabricated by a facile approach relying on electroactive bacteria-induced graphene oxide reduction and confined self-assembly in a capillary tube. The microfiber-like biohydrogel ( d = ∼1 mm) embedded high-density living cells and activated efficient electron exchange between cells and the conductive graphene network. Further, a miniature whole-cell electrochemical biosensing system was developed and applied for fumarate detection under -0.6 V (vs Ag/AgCl) applied potential. Taking advantage of its small size, high local cell density, and excellent electron exchange, this microfiber-like biohydrogel-based sensing system reached a linear calibration curve (R 2 = 0.999) ranging from 1 nM to 10 mM. The limit of detection obtained was 0.60 nM, which was over 1300 times lower than a traditional biosensor for fumarate detection in 0.2 μL microdroplets. This work opened a new dimension for miniature whole-cell electrochemical sensing system design, which provided the possibility for bioelectrochemical detection in small volumes or three-dimensional local detection at high spatial resolutions.

Xueqin Zhang, Hesamoddin Rabiee, Gaofeng Ni et al.

Chemical Engineering Journal • 2022

Sachin Mishra, Md Ashaduzzaman, Prashant Mishra et al.

Biosensors and Bioelectronics • 2016

Rájabather Krishnaraj, Sheela Berchmans, Rajesh K. Sani et al.

Bioresource Technology • 2018

He Zhang, Lingling Zhang, Yujie Han et al.

Biosensors and Bioelectronics • 2017