| 1. |
- Pankratov, Dmitry, et al.
(författare)
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Impact of surface modification with gold nanoparticles on the bioelectrocatalytic parameters of immobilized bilirubin oxidase
- 2014
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Ingår i: Acta Naturae. - : Park Media Ltd. - 2075-8251. ; 6:1, s. 102-106
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Tidskriftsartikel (refereegranskat)abstract
- We unveil experimental evidence that put into question the widely held notion concerning the impact of nanoparticles on the bioelectrocatalytic parameters of enzymatic electrodes. Comparative studies of the bioelectrocatalytic properties of fungal bilirubin oxidase from Myrothecium verrucaria adsorbed on gold electrodes, modified with gold nanoparticles of different diameters, clearly indicate that neither the direct electron transfer rate (standard heterogeneous electron transfer rate constants were calculated to be 31±9 s-1) nor the biocatalytic activity of the adsorbed enzyme (bioelectrocatalytic constants were calculated to be 34±11 s-1) depends on the size of the nanoparticles, which had diameters close to or larger than those of the enzyme molecules.
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| 2. |
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| 3. |
- Pankratov, Dmitry, et al.
(författare)
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The influence of nanoparticles on enzymatic bioelectrocatalysis
- 2014
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Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 4:72, s. 38164-38168
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Tidskriftsartikel (refereegranskat)abstract
- In nearly all papers concerning enzyme–nanoparticle based bioelectronic devices, it is stated that the presence of nanoparticles on electrode surfaces per se enhances bioelectrocatalysis, although the reasons for that enhancement are often unclear. Here, we report detailed experimental evidence that neither an overpotential of bioelectrocatalysis, nor direct electron transfer and bioelectrocatalytic reaction rates for an adsorbed enzyme depend on the size of nanoparticles within the range of 20–80 nm, i.e. for nanoparticles that are considerably larger than the enzyme molecules.
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| 4. |
- Pankratov, Dmitry, et al.
(författare)
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The influence of nanoparticles on enzymatic bioelectrocatalysis
- 2014
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 4:72, s. 38164-38168
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Tidskriftsartikel (refereegranskat)abstract
- In nearly all papers concerning enzyme-nanoparticle based bio-electronic devices, it is stated that the presence of nanoparticles on electrode surfaces per se enhances bioelectrocatalysis, although the reasons for that enhancement are often unclear. Here, we report detailed experimental evidence that neither an overpotential of bioelectrocatalysis, nor direct electron transfer and bioelectrocatalytic reaction rates for an adsorbed enzyme depend on the size of nanoparticles within the range of 20-80 nm, i.e. for nanoparticles that are considerably larger than the enzyme molecules.
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| 5. |
- Blum, Zoltan, et al.
(författare)
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Powering electronic contact lenses : current achievements, challenges, and perspectives
- 2014
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Ingår i: Expert Review of Ophthalmology. - : Expert Reviews. - 1746-9902 .- 1746-9899. ; 9:4, s. 269-273
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Tidskriftsartikel (refereegranskat)abstract
- The recent media hoopla regarding ‘smart’, ‘bionic’, or more appropriately, electronically augmented contact lenses is analyzed in terms of real achievements coupled to the critically important issue of power management. Not depending on the availability, currently or in the near future, of to-the-purpose discrete or integrated electronic devices, power management, including delivery/supply and temporal sustainability, will be an outstanding issue if present-day technology should remain the only option. Radically different approaches have been taken to deliver electric power to electronically augmented contact lenses, that is, ranging from quite simplistic wire-based delivery assemblies, grossly inappropriate for end users, to various elaborate wireless designs drawing on over-the-air power delivery, as well as solar and electrochemical cells. Nonetheless, given the complex restrictions offered by a contact lens, conventional, even state-of-the-art, power management technology is at an impasse, and to ensure a bright future for smart lenses, radical technological measures need to be taken. Bridging the conceptual gap between fuel cells and supercapacitors, an ingenious novel approach to on-lens power management is presented: a charge-storing fuel cell, or alternatively, a self-charging capacitor, that is, a hybrid electric power device.
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| 6. |
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| 7. |
- Falk, Magnus, et al.
(författare)
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Miniature direct electron transfer based enzymatic fuel cell operating in human sweat and saliva
- 2014
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Ingår i: Fuel Cells. - : John Wiley & Sons. - 1615-6846 .- 1615-6854. ; 14:6, s. 1050-1056
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Tidskriftsartikel (refereegranskat)abstract
- We present data on operation of a miniature membrane-less, direct electron transfer based enzymatic fuel cell in human sweat and saliva. The enzymatic fuel cell was fabricated following our previous reports on miniature biofuel cells, utilizing gold nanoparticle modified gold microwires with immobilized cellobiose dehydrogenase and bilirubin oxidase. The following average characteristics of miniature glucose/oxygen biodevices operating in human sweat and saliva, respectively, were registered: 580 and 560 mV open-circuit voltage, 0.26 and 0.1 μW cm–2 power density at a cell voltage of 0.5 V, with up to ten times higher power output at 0.2 V. When saliva collected after meal ingestion was used, roughly a two-fold increase in power output was obtained, with a further two-fold increase by addition of 500 μM glucose. Likewise, the power generated in sweat at 0.5 V increased two-fold by addition of 500 μM glucose.
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| 8. |
- Otrokhov, Grigory, et al.
(författare)
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Enzymatic synthesis of polyaniline/multi-walled carbon nanotube composite with core shell structure and its electrochemical characterization for supercapacitor application
- 2014
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Ingår i: Electrochimica Acta. - : Elsevier. - 0013-4686 .- 1873-3859. ; 123, s. 151-157
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Tidskriftsartikel (refereegranskat)abstract
- A new method involving laccase-mediator system has been developed for environmentally friendly synthesis of polyaniline/multi-walled carbon nanotubes (PANI/MWCNT) composite. Fungal laccase, potassium octocyanomolibdate (4+) and atmospheric oxygen served as catalyst, redox-mediator and terminal oxidant, respectively. The structure, morphology and electrical conductivity of composites with different PANI content were investigated. The energy storage of enzymatically obtained composite consists of an electrical double layer capacitance as well as pseudocapacitance of conducting polymer. The obtained PANI/MWCNT composite with PANI content ca. 49 wt.% had high specific capacitance and cycle stability during doping/dedoping. The specific capacitance of this composite measured by cyclic voltammetry technique with potential scan rate of 5 mV/s was ca. 440 F/g. The specific capacitance of the composite decreased by less than 7% of its maximum value after 1000 scan cycles between -0.1 and 0.7 V. Supercapacitor (SC) shell was made from flexible adhesive tape (regular Scotch tape) and current collector was formed after its separation from the surface of graphite foil. The ethanol dispersion of PANI/MWCNT composite was deposited on the current collector surface. The gel polymer electrolyte (polyvinyl alcohol in 1 M phosphoric acid) was employed as both electrolyte medium and separator. The energy and power densities under an operating window of 0.7 V were ca. 7.03 Wh/kg and 5.2 kW/kg, respectively. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.
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| 9. |
- Pankratov, Dmitry, et al.
(författare)
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A hybrid electric power device for simultaneous generation and storage of electric energy
- 2014
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Ingår i: Energy and Environmental Science. - : Royal Society of Chemistry. ; 7:3, s. 989-993
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Tidskriftsartikel (refereegranskat)abstract
- We herein report on an entirely new kind of electric power device. In the hybrid device, chemical energy is directly converted into electric energy, which is capacitively stored within a singular contrivance. The device is built based on dual-function electrodes, viz. discrete electrodes manifesting simultaneous electrocatalytic and charge-storage features.
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| 10. |
- Pankratov, Dmitry, et al.
(författare)
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Hybrid electric power biodevices
- 2014
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Ingår i: ChemElectroChem. - : John Wiley & Sons. - 2196-0216. ; 1:11, s. 1798-1807
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Tidskriftsartikel (refereegranskat)abstract
- Hybrid electric power biodevices, a new type of electric power-producing device, are a combination of an electrochemical capacitor and a biofuel cell. In this Minireview, we summarise existing knowledge on double-function bioelectrodes, that is, single electrodes concurrently manifesting bio-electrocatalytic and charge-storage features, and describe important historical aspects and achievements in this area. We also discuss a recently proposed method for concomitant electric power generation and storage, which is exemplified by fabricated and characterised self-charging bio-supercapacitors, also termed charge-storing biofuel cells. The electric power in these hybrid devices is uninterruptedly generated by direct transformation of chemical energy into electric energy, as occurs in biofuel cells. The power is simultaneously and directly stored within a single device, relying on different types of capacitance based on reversible charge-transfer reactions (pseudocapacitance) and/or electric double-layer capacitance, as in electrochemical capacitors. We also present some unpublished results on both dual-feature electrodes and hybrid biodevices and briefly highlight the prospects for their application.
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