Hexachloroiridate(IV) as a redox probe for the electrochemical discrimination of B-DNA and M-DNA monolayers on gold

Dinsmore, Michael J.; Lee, Jeremy S.

doi:10.1016/j.jelechem.2008.01.018

Cited by 12 publications

(4 citation statements)

References 35 publications

(45 reference statements)

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“…For example, current-voltage curves of bundles of M-DNA duplexes placed between two electrodes separated by a gap of at least 1 m m have been measured directly [ 20 ] . Moreover, electrochemical investigations of self-assembled DNA monolayers on gold electrodes showed an increased electron transfer rate between different solute redox probes and the gold surface for M-DNA in comparison with B-DNA [ 21,22 ] . In particular, a differential behavior towards base mismatches was observed for B-DNA and M-DNA that was exploited for mismatch detection [ 23 ] .…”

Section: Physical Propertiesmentioning

confidence: 99%

Metal-Mediated Base Pairs in Nucleic Acids with Purine- and Pyrimidine-Derived Nucleosides

Megger

Müller

2011

Metal Ions in Life Sciences

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Metal-mediated base pairs are transition metal complexes formed from complementary nucleosides within nucleic acid double helices. Instead of relying on hydrogen bonds, they are stabilized by coordinative bonds. The nucleosides acting as ligands do not necessarily have to be artificial. In fact, several examples are known of naturally occurring nucleobases (e.g., thymine, cytosine) capable of forming stable metal-mediated base pairs that are highly selective towards certain metal ions. This chapter provides a comprehensive overview of metal-mediated base pairs formed from natural nucleosides or from closely related artificial nucleosides that are pyrimidine or purine derivatives. It addresses the different strategies that lead to the development of these base pairs. The article focuses on structural models for metal-mediated base pairs, their experimental characterization within a nucleic acid, and on their possible applications.

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Section: Physical Propertiesmentioning

confidence: 99%

Metal-Mediated Base Pairs in Nucleic Acids with Purine- and Pyrimidine-Derived Nucleosides

Megger

Müller

2011

Metal Ions in Life Sciences

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“…In many electrochemical approaches, such as those discussed above, solution-soluble redox-active molecules are used on the basis of their permeability through the thin films covering the electrode surface . For example, TEMPO radical (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl), , ferrocene carboxylic acid, , hexachloroiridate(III), hexaammineruthenium(II)/(III), and ferrocyanide redox couples have been used profusely to portray screen printed electrodes, DNA modified electrodes, and porous electrodes in general. − All the above probes give rise to fast surface insensitive charge transfer processes, which make them suitable for the study of porous, carbon modified electrodes, where the material structure will be the main factor influencing the electrochemical behavior …”

Section: Introductionmentioning

confidence: 99%

Electrochemical Behavior of Different Diffusional Redox Probes on a Porous Acetylene Black Electrode: Mass Transport Modes and Electrostatic Effects

Santos,

Lorca,

Abad

et al. 2024

J. Phys. Chem. C

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The need for high-performance electrodes for electrical energy generation, conversion, and storage has increased the use of carbon nanomaterials as smart surface modifiers of working electrodes. Among carbon nanomaterials, common and inexpensive carbon blacks have spurred the scientific community's interest due to their outstanding capabilities as electrode nanomodifiers, typically combined with an ionomer forming carbonaceous inks. Determining the key factors that can limit or enhance the overall electrochemical response of the employed redox-active species is essential to ascertain the impact on the performance of a hypothetical device, as well as to understand and elucidate reaction mechanisms. Moreover, maximizing the use of the area actually available for the electrochemical active species inside the carbon matrix is of paramount importance. Thus, in this work, the analysis of the electrochemical responses of six redox solution-soluble probes is investigated by cyclic voltammetry and a rotating disk electrode at a GC electrode modified with a metal-free carbon ink formed by a mixture of acetylene black and the ionomer Nafion. The experimental responses show mixed thin-layer and semi-infinite behavior to different degrees depending on the charge of the redox probe. The study of the causes underlying these findings reveals a strong electrostatic influence of the ionomer, leading to the appearance of blocking or trapping effects depending on the charge number of the redox probe. Such effects can compromise the validity of the well known and broadly used procedures of data analysis for porous electrodes, which is critically analyzed.

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“…(ii) [IrCl 6 ] 2is very stable and meta-stable from pH 0 to 10, enabling us to measure the rate constants in such a wide pH range [20][21][22]. (iii) It has been used as a redox probe to discriminate DNA monolayers and to obtain chemical information of oxidative stress in biological matrixes [23,24].…”

Section: Introductionmentioning

confidence: 99%

Antioxidative Reactivity of L-Ascorbic Acid and D-Isoascorbic Acid Species towards Reduction of Hexachloroiridate (IV)

Zhang

Xia

Zhang

et al. 2021

Journal of Chemistry

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The pair [IrCl6]2–/[IrCl6]3– has been demonstrated to be a good redox probe in biological systems while L-ascorbic acid (AA) is one of the most important antioxidants. D-isoascorbic acid (IAA) is an epimer of AA and is widely used as an antioxidant in various foods, beverages, meat, and fisher products. Reductions of [IrCl6]2– by AA and IAA have been analyzed kinetically and mechanistically in this work. The reductions strictly follow overall second-order kinetics and the observed second-order rate constants were collected in the pH region of 0 ≤ pH ≤ 2.33 at 25.0°C. Spectrophotometric titration experiments revealed a well-defined 1 : 2 stoichiometry, namely Δ[AA] : Δ[Ir(IV)] or Δ[IAA] : Δ[Ir(IV)] = 1 : 2, indicating that L-dehydroascorbic acid (DHA) and D-dehydroisoascorbic acid (DHIA) were the oxidation products of AA and IAA, respectively. A reaction mechanism is suggested involving parallel reactions of [IrCl6]2– with three protolysis species of AA/IAA (fully protonated, monoanionic, and dianionic forms) as the rate-determining steps and formation of ascorbic/isoascorbic and ascorbate/isoascorbate radicals; in each of the steps, [IrCl6]2– acquires an electron via an outer-sphere electron transfer mode. Rate constants of the rate-determining steps have been derived or estimated. The fully protonated forms of AA and IAA display virtually identical reactivity whereas ascorbate and isoascorbate monoanions have a significant reactivity difference. The ascorbate and isoascorbate dianions are extremely reactive and their reactions with [IrCl6]2– proceed with the diffusion-controlled rate. The species versus pH and the species reactivity versus pH distribution diagrams were constructed endowing that the ascorbate/isoascorbate monoanionic form dominated the total reactivity at physiological pH. In addition, the value of pKa1 = 3.74 ± 0.05 for IAA at 25.0°C and 1.0 M ionic strength was determined in this work.

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Hexachloroiridate(IV) as a redox probe for the electrochemical discrimination of B-DNA and M-DNA monolayers on gold

Cited by 12 publications

References 35 publications

Metal-Mediated Base Pairs in Nucleic Acids with Purine- and Pyrimidine-Derived Nucleosides

Metal-Mediated Base Pairs in Nucleic Acids with Purine- and Pyrimidine-Derived Nucleosides

Electrochemical Behavior of Different Diffusional Redox Probes on a Porous Acetylene Black Electrode: Mass Transport Modes and Electrostatic Effects

Antioxidative Reactivity of L-Ascorbic Acid and D-Isoascorbic Acid Species towards Reduction of Hexachloroiridate (IV)

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