1,742 research outputs found
Non-competitive reversible inhibition of laccase by H2O2 in osmium mediated layer-by-layer multilayer O2 biocathodes
No full textA systematic study of the inhibition of laccase by hydrogen peroxide in oxygen biocathodes composed of layer-by-layer selfassembled multilayers of Trametes-trogii laccase and osmium derivatized poly(allylamine) redox mediator has been accomplished using a rotating disc electrode at different electrode potentials, oxygen partial pressures and hydrogen peroxide concentrations. The experimental results are consistent with a reversible non-competitive inhibition mechanism in agreement with the Solomon mechanism for laccase previously reported.Fil: Grattieri, Matteo. Politecnico di Milano; Italia. Università degli Studi di Milano; ItaliaFil: Scodeller, Pablo David. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Inorgánica, Analítica y Química Física; ArgentinaFil: Adam, Catherine. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Inorgánica, Analítica y Química Física; Argentina. University Of Tartu.; EstoniaFil: Calvo, Ernesto Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Inorgánica, Analítica y Química Física; Argentin
Facilitated Electron Hopping in Nanolayer Oxygen-Insensitive Glucose Biosensor for Application in a Complex Matrix
No full textElectrochemical experimental evidence of facilitated electron transfer in a sub-micrometer biosensor is presented. Layer-by-layer self-assembled deposition provides the unique advantage to specifically control the thickness of the biosensors, allowing an oxygen-insensitive device with a film thickness of 70 nanometers to be obtained. The biosensor is based on a poly(allylamine) osmium redox mediator and glucose 1-oxidase. The immobilized enzyme contributes to the signal generation through the full biosensor thickness, with no loss of “active enzyme” in the outer layer of the biosensor through reaction with oxygen, as reported in the case of thick redox hydrogels. The application of the biosensor in complex matrices was approached with tests in wastewater. Encapsulation of the biosensor with Nafion® membrane ensured the protection of the enzyme molecules from the external environment, allowing the successful application of the sensor in a complex matrix
Chloroplast biosolar cell and self-powered herbicide monitoring
No full textUtilizing chloroplasts in biosolar cells offers a sustainable approach for sunlight harvesting. However, the limited electrochemical communication between these biological entities and an electrode surface has led to complex device setups, hindering their application in the field. Herein, a cross-linker enables a simple photoanode architecture with enhanced photoexcited electron transfer between chloroplasts and abiotic electrodes. The improved “wiring” of the photosynthetic electron transfer chain resulted in a five-fold increase in the biophotocurrent. The biophotoanode is applied in a Pt-free, portable biosolar cell allowing the in situ self-powered monitoring of diuron within limits set by the Environmental Protection Agency
Draft Genome Sequence of Salinivibrio sp. Strain EAGSL, a Biotechnologically Relevant Halophilic Microorganism
No full textThe halophilic bacterium Salinivibrio sp. strain EAGSL was isolated from the Great Salt Lake (Utah) for use in microbial electrochemical technologies experi- encing fluctuating salt concentrations. Genome sequencing was performed with Ion Torrent technology, and the assembled genome reported here is 3,234,770 bp with a GC content of 49.41%
Microbial fuel cells in saline and hypersaline environments: Advancements, challenges and future perspectives
No full textThis review is aimed to report the possibility to utilize microbial fuel cells for the treatment of saline and hypersaline solutions. An introduction to the issues related with the biological treatment of saline and hypersaline wastewater is reported, discussing the limitation that characterizes classical aerobic and anaerobic digestions. The microbial fuel cell (MFC) technology, and the possibility to be applied in the presence of high salinity, is discussed before reviewing the most recent advancements in the development of MFCs operating in saline and hypersaline conditions, with their different and interesting applications. Specifically, the research performed in the last 5 years will be the main focus of this review. Finally, the future perspectives for this technology, together with the most urgent research needs, are presented
Revisiting direct electron transfer in nanostructured carbon laccase oxygen cathodes
No full textThe biocatalytic electroreduction of oxygen has been studied on large surface area graphite and Vulcan® carbon electrodes with adsorbed Trametes trogii laccase. The electrokinetics of the O2 reduction reaction (ORR) was studied at different electrode potentials, O2 partial pressures and concentrations of hydrogen peroxide.Even though the overpotential at 0.25 mA·cm-2 for the ORR at T1Cu of the adsorbed laccase on carbon is 0.8 V lower than for Pt of similar geometric area, the rate of the reaction and thus the operative current density is limited by the enzyme reaction rate at the T2/T3 cluster site for the adsorbed enzyme. The transition potential for the rate determining step from the direct electron transfer (DET) to the enzyme reaction shifts to higher potentials at higher oxygen partial pressure.Hydrogen peroxide produced by the ORR on bare carbon support participates in an inhibition mechanism, with uncompetitive predominance at high H2O2 concentration, non-competitive contribution can be detected at low inhibitor concentration.Fil: Adam, Catherine. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Scodeller, Pablo David. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Grattieri, Matteo. Politecnico di Milano; ItaliaFil: Villalba, Matias Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Calvo, Ernesto Julio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentin
Self-Powered Biosensors
No full textSelf-powered electrochemical biosensors utilize biofuel cells as a simultaneous power source and biosensor, which simplifies the biosensor system, because it no longer requires a potentiostat, power for the potentiostat, and/or power for the signaling device. This review article is focused on detailing the advances in the field of self-powered biosensors and discussing their advantages and limitations compared to other types of electrochemical biosensors. The review will discuss self-powered biosensors formed from enzymatic biofuel cells, organelle-based biofuel cells, and microbial fuel cells. It also discusses the different mechanisms of sensing, including utilizing the analyte being the substrate/fuel for the biocatalyst, the analyte binding the biocatalyst to the electrode surface, the analyte being an inhibitor of the biocatalyst, the analyte resulting in the blocking of the bioelectrocatalytic response, the analyte reactivating the biocatalyst, Boolean logic gates, and combining affinity-based biorecognition elements with bioelectrocatalytic power generation. The final section of this review details areas of future investigation that are needed in the field, as well as problems that still need to be addressed by the field
Decoupling energy and power
No full textBiological photovoltaic devices (BPVs) use photosynthetic microorganisms to produce electricity, but low photocurrent generation impedes their application. Now, a micro-scale flow-based BPV system is reported with power density outputs similar to that of large-scale biofuels
Birthday
No full textThis Special Collection is dedicated to Plamen Atanassov to celebrate his 60th birthday. For all those of you that know Plamen, you are well aware of his passion and devotion to science, technology, and history. Plamen is an excellent example of a scientist who combines enthusiasm with the highest level of energy and contribution. During his scientific career, he has distinguished himself not only for his prolific publication record, but also for the most interdisciplinary and highly collaborative character of all his research related to electrochemistry. Plamen has proven to be a critical leader in electrocatalysis and bioelectrochemistry with many well-recog- nized breakthroughs that guide the research directions we travel today. All these accomplishments have been possible thanks to a most fortunate combination of diverse technical preparedness, analytical talent, technical inventiveness, and inter-person organizational skill. In this short celebration, we first briefly describe Plamen’s scientific history, which starts in a beautiful, culturally rich and fascinating country in the East of Europe (Bulgaria) leading to his current employment at the University of California Irvine. Secondly, the four scientists leading this celebrating initiative will briefly describe personal experiences and anecdotes related to the impact that Plamen, as an “older brother”, mentor, colleague, and friend has brought into our nowadays lives
Sustainable Hypersaline Microbial Fuel Cells: Inexpensive Recyclable Polymer Supports for Carbon Nanotube Conductive Paint Anodes
No full textMicrobial fuel cells are an emerging technology for wastewatertreatment, but to be commercially viable and sustainable, theelectrode materials must be inexpensive, recyclable, and relia-ble. In this study,recyclable polymericsupports were exploredfor the development of anode electrodes to be applied insingle-chamber microbial fuel cells operated in field under hy-persalineconditions. The support was covered with acarbonnanotube (CNT) based conductive paint, and biofilms wereable to colonize the electrodes. The single-chamber microbialfuelcellswithPt-freecathodesdeliveredareproduciblepoweroutput after 15 days of operation to achieve12: 1mWm@2atacurrentdensity of 69 : [email protected] decrease of the per-formance in long-term experiments was mostly relate dtoinor-ganic prec ipitates on the cathodeelectrode anddid not affectthe performance of the anode,asshown by experiments inwhich the cathode was replaced and the fuel cell performancewas regenerated. The resultsofthese studies showthe feasibil-ityofpolymericsupportscoatedwithCNT-basedpaintformicrobial fuel cell application
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