Electrochemistry of Biopolymers

Berg, Hermann

doi:10.1007/978-1-4613-2359-4_3

Cited by 12 publications

(4 citation statements)

References 83 publications

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“…As to the charge transferability through DNA, it has been a subject of controversial scientific debates since the discovery of the double helix. , Berg proposed the electron-transfer mechanism of DNA electrochemistry that DNA may have some semiconductor-like characteristics and that the electron migrated by “hopping” from base to base. , On account of this, the photoelectrochemistry of DNA may possibly throw new light on the DNA conducting property . Barton et al later reported their exciting discovery that long distance photoinduced electron transfer (>40 Å) may be mediated by the DNA helix which was described as “molecular wire”; however, the photoinduced electron transfer between reactants bound to DNA, or between bases contained within the π stack, has led to different conclusions regarding the nature of DNA as a medium for long-range charge transport. − In addition, based on the DNA photoelectrochemistry itself, PEC detection of DNA damage and DNA hybridization were then reported.…”

Section: Pec Dna Biosensorsmentioning

confidence: 99%

Photoelectrochemical DNA Biosensors

2014

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Section: Pec Dna Biosensorsmentioning

confidence: 99%

Photoelectrochemical DNA Biosensors

2014

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“…It has been shown recently that DNA can conduct electrons through its a-stacked arrays of base pairs behaving thus like a wire [40, 411. The possibility of reduction of bases at the electrode by electron hopping was considered earlier [42]. At present we do not know whether the above processes influence the voltammetric or chronopotentiometric signals of linear dsDNAs.…”

Section: Single-and Double-stranded Dnasmentioning

confidence: 98%

Chronopotentiometric stripping of DNA at mercury electrodes

et al. 1997

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Denatured (single-stranded, ss) and native (double-stranded, ds) DNAs were studied by constant current chronopotentiometric stripping analysis (CPSA) at a hanging mercury drop electrode (HMDE). In agreement with the previous voltammetric studies at neutral pH values ssDNA produced CPS cathodic peak CA (due to reduction of cytosine and adenine) and anodic peak G (due to oxidation of the guanine reduction product) at drldE against E curves. The same peaks produced by dsDNA were substantially smaller. Differences in heights (areas) of peaks G and CA produced by ss and dsDNAs at partial and full electrode coverage are compared and discussed. Using CPSA a well-developed and symmetrical peak CA was obtained at low DNA concentrations compared to a poorly measurable inflection produced by differential pulse or linear sweep voltammetries under the same conditions. The CPS peak CA can be used also in adsorptive transfer stripping (AdTS, medium exchange) experiments. In the previous AdTS voltammetric measurements only peak G was exploited while the voltammetric peak CA was poorly defined to be of any use in combination with DNA-modified electrodes. CPS peaks were measured in the presence and in absence of air. It was shown that in the presence of air peak CA is enhanced while peak G decreased. We compared the CPSA of ssDNA at the mercury and carbon paste electrodes (CPE). The CPS peak G (obtained with HMDE) seems to be the best choice for the electrochemical determination of DNA in highly diluted solution. With 10min adsorptive preconcentration a detection limit below 20 ng of ssDNA per mL was obtained at HMDE. At CPE the limit of detection (of the same ssDNA) was at least two-fold higher.

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“…These properties are of vital importance in applications of these modified electrodes such us the catalytic reduction of a substrate. Here the challenge is to obtain very reversible redox processes, without the interference of other species ͑e.g., oxygen͒ and relatively negative potentials ͑to carry out the electrocatalytic reduction of substances such as [23][24][25][26][27] disulfides, purines, olefins acrylonitrile, artemisin, ...͒. The splitting of the first reduction peak has been observed in many cases, although sometimes contradictory results in the literature can be found in spite of using the same or extremely similar experimental conditions.…”

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confidence: 99%

Electrochemistry of Langmuir-Blodgett Films Incorporating Both a Viologen Derivative and Tetracyanoquinodimethane

Martı́n¹,

Cea²,

Gascón³

et al. 2002

J. Electrochem. Soc.

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A positively charged monolayer of a viologen derivative containing two long alkyl chains was prepared. Tetracyanoquinodimethane radical anions (TCNQ •Ϫ ) were incorporated into the Langmuir-Blodgett film during the transference process as the counterions from a subphase containing an aqueous solution of LiTCNQ. Stable monolayers were transferred onto indium tin oxide electrodes and the electrochemical properties of the films were analyzed in terms of experimental variables including the nature of the counterions, the degree of order of the films, and the number of transferred layers. These well-ordered films show very reversible electrochemical processes for the viologen, quite negative redox potentials of the viologen moieties, a ⌫ c /⌫ a ratio of 1, and no splitting of the first viologen reduction peak. The control of these properties is quite important in applications such as the catalytic reduction of a substrate.The electrochemical properties of immobilized redox molecules at electrode surfaces have focused the interest of many researchers over the last decade. Among the techniques used to achieve a welldefined molecular arrangement of redox moieties onto electrode surfaces, the Langmuir-Blodgett ͑LM͒ method has been one of the most widely used because it allows creation of films with a high internal order, with the desired number of layers, the possibility of depositing alternate monolayers of different molecules, etc. Thus, the LB technique can provide us new insights on the electron-transfer reactions at interfaces, as well as the possibility of obtaining highly ordered modified electrodes with practical applications such as molecular electronics, electrocatalysis, synthesis, and electroanalysis. 1-3 1,1Ј-Disubstituted 4,4Ј-bipyridyls, so-called viologens, are of great electrochemical interest because of their three oxidation states and the high reversibility of their redox reactions ͑especially the first one͒; 4 their use in solar energy storage devices and as electron mediators in herbicides; 5 preparation of chemically modified electrodes; 1 catalytic reduction of a substrate; 6 studies of the rates of electron transfer at electrode substrate-film interface; 7 their potential electrochromic applications; 8 their use in electrochromic writing paper; 9 bioelectronic devices; 10 electron-transfer mediation to various biological molecules; 11 and surface-enhanced Raman studies of adsorption at electrode surfaces, 12 etc.Several research groups have investigated the electrochemical properties of LB films incorporating both different kinds of viologen dicationic derivatives and different kinds of anions. These studies have tried to work out how the number and length of the alkyl chains, as well as the nature of the anion, determine the electrochemical properties of the modified electrodes. 10,[13][14][15][16][17][18][19][20][21][22] In this paper we focus our attention on three important points in the understanding of the viologen's electrochemical behavior: (i) the splitting of the first reduction peak; (ii...

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Electrochemistry of Biopolymers

Cited by 12 publications

References 83 publications

Photoelectrochemical DNA Biosensors

Photoelectrochemical DNA Biosensors

Chronopotentiometric stripping of DNA at mercury electrodes

Electrochemistry of Langmuir-Blodgett Films Incorporating Both a Viologen Derivative and Tetracyanoquinodimethane

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