Direct Electron Transfer Between Ligninolytic Redox Enzymes and Electrodes

Christenson, Andreas; Dimcheva, Nina; Ferapontova, Elena E.; Gorton, Lo; Ruzgas, Tautgirdas; Stoica, Leonard; Shleev, Sergey; Yaropolov, A. I.; Haltrich, Dietmar; Thorneley, R. N. F.; Aust, Steven D.

doi:10.1002/elan.200403004

Cited by 137 publications

(98 citation statements)

References 181 publications

(186 reference statements)

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Section: Introductionmentioning

confidence: 99%

“…Porous electrodes can be used to encapsulate the enzyme within a network of cavities, shortening the distance for electron transfer to the redox active site, which will promote more efficient and rapid rates of electron transfer [5]. However, the number of redox enzymes capable of interacting directly with the electrode while catalyzing the enzymatic reaction is limited, with estimates of approximately 5% of all enzymes exhibiting such a response [6].DET in enzymes was first described in 1978 for laccase (Lc) [7][8]. Lc, together with ceruloplasmin, ascorbate oxidase, and bilirubin oxidase (BOx) belongs to the group of Cuproteins which are also known as blue multicopper oxidases.…”

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confidence: 99%

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Direct electron transfer of Trametes hirsuta laccase adsorbed at unmodified nanoporous gold electrodes

Salaj-Kośla

Pöller

Schuhmann

et al. 2013

Bioelectrochemistry

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The enzyme Trametes hirsuta laccase undergoes direct electron transfer at unmodified nanoporous gold electrodes, displaying a current density of 28 A/cm 2 . The response indicates that ThLc was immobilised at the surface of the nanopores in a manner which promoted direct electron transfer, in contrast to the absence of a response at unmodified polycrystalline gold electrodes. The bioelectrocatalytic activity of ThLc modified nanoporous gold electrodes was strongly dependent on the presence of halide ions. Fluoride completely inhibited the enzymatic response, whereas in the presence of 150 mM Cl -, the current was reduced to 50% of the response in the absence of Cl -. The current increased by 40% when the temperature was increased from 20°C to 37°C. The response is limited by enzymatic and/or enzyme electrode kinetics and is 30% of that observed for ThLc co-immobilised with an osmium redox polymer. Keywords: Laccase, direct electron transfer, nanoporous gold 2 IntroductionElectron transfer (ET) reactions are ubiquitous in nature. Controlling the rate of these reactions can be of significant benefit in developing biochemical systems that utilise redox proteins and enzymes and in particular, in applications that provide power for implanted or portable electronic devices. ET can be achieved directly (direct electron transfer, DET) or by the use of mediators (mediated electron transfer, MET) to shuttle electrons between the redox centre of the enzyme and the electrode. However, mediators are unselective and can also give rise to interfering effects [1][2][3]. DET-based devices offer high selectivity and sensitivity due to the absence of mediators. In addition, devices based on DET operate at potentials close to the redox potential of the enzyme, maximising the potential difference between the cathode and anode for biofuel cell applications [2]. Moreover, DET can be used to provide detailed information on the kinetics and thermodynamics of the ET process. However, the low stability of the enzyme layer together with the long distances over which ET occurs, represent major obstacles for DET based devices. In addition, the shielding mechanism of the enzymatic redox centre by the protein shell can disrupt DET [2,4]. One approach in optimizing and enabling rapid DET is to design the electrode surface with an architecture which promotes efficient rates of ET. In this way the electrode morphology ensures the most efficient orientation of the enzymatic redox centre and facilitates communication with the electroactive surface. Porous electrodes can be used to encapsulate the enzyme within a network of cavities, shortening the distance for electron transfer to the redox active site, which will promote more efficient and rapid rates of electron transfer [5]. However, the number of redox enzymes capable of interacting directly with the electrode while catalyzing the enzymatic reaction is limited, with estimates of approximately 5% of all enzymes exhibiting such a response [6].DET in enzymes was first described in 1978 fo...

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Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Direct electron transfer of Trametes hirsuta laccase adsorbed at unmodified nanoporous gold electrodes

Salaj-Kośla

Pöller

Schuhmann

et al. 2013

Bioelectrochemistry

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“…Sensitive biosensors have been developed for the detection of DNA, 4 prostate specific antigen, 5 and thrombin. 10 The development of electrochemical devices based on direct electron transfer (DET) between an immobilized enzyme and an electrode surface, has been hampered by the (a) limited number of redox enzymes exhibiting DET at the surface of an electrode (approximately 5% of known redox enzymes), 11 (b) limited stability of enzyme electrodes, and (c) low, observed, current densities. 12 Achieving DET requires selective modification of the electrode surface to enable optimal orientation of the enzyme and to minimize the distance between the electrochemically active centre and the electrode surface.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Nanoporous Gold Electrodes for Bioelectrochemical Applications

Scanlon¹,

Salaj-Kośla²,

Belochapkine³

et al. 2011

Langmuir

104

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ABSTRACT. The high surface areas of nanostructured electrodes can provide for significantly enhanced surface loadings of electroactive materials. The fabrication and characterisation of nanoporous gold (np-Au) substrates as electrodes for bioelectrochemical applications is described.Robust np-Au electrodes were prepared by sputtering a gold-silver alloy onto a glass support and subsequent de-alloying of the silver component. Alloy layers were prepared with either a uniform or non-uniform distribution of silver and, post de-alloying, showed clear differences in morphology on characterisation with scanning electron microscopy. Redox reactions under kinetic control, in particular measurement of the charge required to strip a gold oxide layer, provided the most accurate measurements of the total electrochemically addressable electrode surface area, A real .Values of A real up to 28 times that of the geometric electrode surface area, A geo , were obtained. For diffusion controlled reactions overlapping diffusion zones between adjacent nanopores established limiting semi-infinite linear diffusion fields where the maximum current density was dependent on A geo . The importance of measuring the surface area available for the immobilisation was determined 2 using the redox protein, cyt c. The area accessible to modification by a biological macromolecule, A macro , such as cyt c was reduced by up to 40 % compared to A real , demonstrating that the confines of some nanopores were inaccessible to large macromolecules due to steric hindrances. Preliminary studies on the preparation of np-Au electrodes modified with osmium redox polymer hydrogels and Myrothecium verrucaria bilirubin oxidase (MvBOD) as a biocathode were performed; current densities of 500 A cm -2 were obtained in unstirred solutions.

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“…mediator), the increase of specificity for target analyte, the removal of interferences due to usually low polarization potential at the working electrode, etc. (Christensson et al, 2004;Stoica et al, 2005). Nevertheless, only limited number of enzymes (mostly heme -or copper -containing oxidoreductases) has been proven to work for the third generation biosensors and their common feature is that a metalcontaining cofactor that functions either as a catalytic cofactor and/or as an intramolecular electron transfer cofactor is embedded in the protein shell.…”

Section: Introductionmentioning

confidence: 99%

Soft Computing Techniques in Modelling the Influence of pH and Temperature on Dopamine Biosensor

Rangelova¹,

Tsankova²,

Dimcheva³

2010

Intelligent and Biosensors

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Direct Electron Transfer Between Ligninolytic Redox Enzymes and Electrodes

Cited by 137 publications

References 181 publications

Direct electron transfer of Trametes hirsuta laccase adsorbed at unmodified nanoporous gold electrodes

Direct electron transfer of Trametes hirsuta laccase adsorbed at unmodified nanoporous gold electrodes

Characterization of Nanoporous Gold Electrodes for Bioelectrochemical Applications

Soft Computing Techniques in Modelling the Influence of pH and Temperature on Dopamine Biosensor

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