An Electrochemical and Spectroscopic Characterization of Pencil Graphite Electrodes

Kariuki, James K.

doi:10.1149/2.007209jes

Cited by 87 publications

(66 citation statements)

References 61 publications

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“…[51,52] To prepare the electrocatalytic PQQ-modified electrode, the graphite electrode was reacted with PEI, and then the amino groups of the physically adsorbed PEI were reacted with the carboxylic groups of PQQ to yield covalent bonds in the presence of EDC/NHS in HEPES buffer under standard conditions of carbodiimide coupling reactions (see experimental details in the Supporting Information). 0.8 cm 2 ).…”

Section: Preparation Of the Pqq-and Alginate-modified Electrodesmentioning

confidence: 99%

Bioelectronic Interface Connecting Reversible Logic Gates Based on Enzyme and DNA Reactions

et al. 2016

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It is believed that connecting biomolecular computation elements in complex networks of communicating molecules may eventually lead to a biocomputer that can be used for diagnostics and/or the cure of physiological and genetic disorders. Here, a bioelectronic interface based on biomolecule-modified electrodes has been designed to bridge reversible enzymatic logic gates with reversible DNA-based logic gates. The enzyme-based Fredkin gate with three input and three output signals was connected to the DNA-based Feynman gate with two input and two output signals-both representing logically reversible computing elements. In the reversible Fredkin gate, the routing of two data signals between two output channels was controlled by the control signal (third channel). The two data output signals generated by the Fredkin gate were directed toward two electrochemical flow cells, responding to the output signals by releasing DNA molecules that serve as the input signals for the next Feynman logic gate based on the DNA reacting cascade, producing, in turn, two final output signals. The Feynman gate operated as the controlled NOT gate (CNOT), where one of the input channels controlled a NOT operation on another channel. Both logic gates represented a highly sophisticated combination of input-controlled signal-routing logic operations, resulting in redirecting chemical signals in different channels and performing orchestrated computing processes. The biomolecular reaction cascade responsible for the signal processing was realized by moving the solution from one reacting cell to another, including the reacting flow cells and electrochemical flow cells, which were organized in a specific network mimicking electronic computing circuitries. The designed system represents the first example of high complexity biocomputing processes integrating enzyme and DNA reactions and performing logically reversible signal processing.

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Section: Preparation Of the Pqq-and Alginate-modified Electrodesmentioning

confidence: 99%

Bioelectronic Interface Connecting Reversible Logic Gates Based on Enzyme and DNA Reactions

et al. 2016

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“…Pencil lead used as a substrate for electrodeposition of Ta is low‐cost, readily available, and disposable carbon material, and there are a number of reports on pencil lead as an electrode material. Pencil leads showed a fast rate of electron‐transfer for Fe(CN) 6 3−/4− and Ru(NH 3 ) 6 3+/2+ redox systems, illustrating the pencil lead electrode is useful for conducting simple electrochemical measurements instead of expensive commercial carbon electrodes . Pencil lead based electrodes have been used to analyze trace metal, DNA, and various biological compounds .…”

Section: Introductionmentioning

confidence: 89%

Real‐time Selective Detection of Hydrogen Peroxide Based on a Tantalum Deposited Pencil Lead Electrode for Evaluation of Enzyme Activities

Lee

2017

Electroanalysis

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In this study, we have carried out electrodeposition of tantalum (Ta) nanostructures on pencil lead electrode in non‐aqueous media at room temperature by applying a constant potential. The deposited Ta on pencil lead was examined for the catalytic effect regarding hydrogen peroxide (H2O2) reduction with voltammetry and amperometry. Ta/pencil lead electrode exhibited amperometric sensitivity of 0.317 μA mM−1 cm−2 and fast response time of 0.75 s, where selective detection of H2O2 was fulfilled without interruption from common electroactive biomaterials such as O2, uric acid, ascorbic acid, dopamine, acetamidophenol, and glucose. For practical applications, the dynamic concentration changes of H2O2 during catalase and glucose oxidase‐involved reactions, either eliminating or producing H2O2, were successfully traced in real time with as‐prepared electrode. From the kinetics study for catalase and glucose oxidase, we evaluated Michaelis constants (Kmapp) as 7.8 mM for catalase and 37 mM for glucose oxidase, respectively.

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“…The surface concentration of the immobilized PQQ (vs. geometrical area of the electrode surface, without taking into account the electrode roughness) was ca. 1×10 −9 mol cm −2 , which is reasonable for a monolayer coverage, assuming an electrode roughness factor of about 10 . Cyclic voltammograms obtained on the PQQ‐modified electrode in the absence and presence of NADH, Figure , inset, show the increase of the anodic current when NADH is present corresponding to the NADH electrocatalytic oxidation.…”

Section: Figurementioning

confidence: 99%

An Enzyme‐based 1:2 Demultiplexer Interfaced with an Electrochemical Actuator

et al. 2016

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An enzyme-based 1:2 demultiplexer is designed in a flow system composed of three cells where each one is modified with a different enzyme: hexokinase, glucose dehydrogenase and glucose-6-phosphate dehydrogenase. The Input signal activating the biocatalytic cascade is represented by glucose, while the Address signal represented by ATP is responsible for directing the Input signal to one of the output channels, depending on the logic value of the Address. The biomolecular 1:2 demultiplexer is extended to include two electrochemical actuators releasing entrapped DNA molecules in the active output channel. The modular design of the system allows for easy exchange and extension of the functional elements. The present demultiplexer can be easily integrated in various biomolecular logic systems, including different logic gates based on the enzyme- or DNA-based reactions, as well as containing different chemical actuators, for example, with a biomolecular release function.

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An Electrochemical and Spectroscopic Characterization of Pencil Graphite Electrodes

Cited by 87 publications

References 61 publications

Bioelectronic Interface Connecting Reversible Logic Gates Based on Enzyme and DNA Reactions

Bioelectronic Interface Connecting Reversible Logic Gates Based on Enzyme and DNA Reactions

Real‐time Selective Detection of Hydrogen Peroxide Based on a Tantalum Deposited Pencil Lead Electrode for Evaluation of Enzyme Activities

An Enzyme‐based 1:2 Demultiplexer Interfaced with an Electrochemical Actuator

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