Theory of Voltammetry at Constant Current. IV. Electron Transfer Followed by Chemical Reaction

Delahay, Paul; Mattax, C.C.; Berzins, Talivaldis

doi:10.1021/ja01650a017

Cited by 107 publications

(20 citation statements)

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“…The output signal is the cell potential, which changes over time and is applied to the detection compartment as voltage input to generate ECL. As time proceeds, the concentration of the electroactive species at the electrode surface will be depleted at a transition time τ, giving a drastic change in potential. − According to the Sand equation, the square root of the transition time should be linearly dependent on the concentration of the locally depleted species as follows: , where i is the applied current, c j is the initial concentration of analyte j , n is the number of transferred electrons (for ion-selective membranes, n becomes z , the valency of j ), F is the Faraday constant, A is the electrode area, and D j is the diffusion coefficient of j . The time at which ECL reaches maximum intensity should coincide with the chronopotentiometric transition time, which is achieved with the help of a voltage adapter.…”

Section: Resultsmentioning

confidence: 99%

Electrogenerated Chemiluminescence for Chronopotentiometric Sensors

et al. 2019

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We introduce here a general strategy to read out chronopotentiometric sensors by electrogenerated chemiluminescence (ECL). The potentials generated in chronopotentiometry in a sample compartment are used to control the ECL in a separate detection compartment. A three-electrode cell is used to monitor the concentration changes of the analyte, while luminol-H 2 O 2 system is responsible for ECL. The principle was shown to be feasible by theoretical simulations, indicating that the sampled times at a chosen potential, rather than traditional transition times, similarly give linear behavior between concentration and square root of sampled time. With the help of a voltage adapter, the experimental combination between chronopotentiometry and ECL was successfully implemented. As an initial proof of concept, the ferro/ferricyanide redox couple was investigated. The square root of time giving maximum light output changed linearly with ferrocyanide concentration in the range from 0.70 mM to 4.81 mM. The method was successfully applied to the visual detection of carbonate alkalinity from 0.06 mM to 0.62 mM using chronopotentiometry at an ionophore-based hydrogen ion-selective membrane electrode. The measurements of carbonate in real samples including river water and commercial mineral water were successfully demonstrated.

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Section: Resultsmentioning

confidence: 99%

Electrogenerated Chemiluminescence for Chronopotentiometric Sensors

et al. 2019

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“…Table 3.1 contains results of such a calculation using Eqs. (12) and (15) This relation is given by (1) where iL is the limiting current due to convective diffusion of the reacting ions (amp), n is the number of elec.trons involved in the redox reaction, C is reactant concentration (moles/cm 3 ), D is the diffusion coefficient (cm 2 /sec), tis capillary length (em), and Vf is volume flow rate (cm 3 /sec). It is noteworthy that capillary diameter has no effect on the limiting current.…”

Section: Effect Of Migration Of Reactants and Productsmentioning

confidence: 99%

“…the case where three ions are present in the system: Na , Cl , and X , 1. See Section 6, this report.…”

Section: + -mentioning

confidence: 99%

Reactions and transport phenomena at surfaces. Water research program biennial progress report for the period March 15, 1966--March 15, 1968

Posey¹,

Moore²,

Kraus³

1973

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“…When the chemical reaction is rapid and reversible, the behavior is formally the same as if no complication were present (Tables I and II, entry 7) but the Ei/, includes a term dependent on the equilibrium constant for the chemical reaction. The case of a slow but rever- sible chemical reaction (Tables I and II, entry 8) has been discussed in detail by Delahay and coworkers (4) and that of a slow irreversible reaction (Tables I and II, entry 10) by Snead and Remick (11) and by Testa and Reinmuth (IS). The reader is referred to these discussions for methods of treatment of data and limits of applicability of equations.…”

Section: Nernstian Behavior With First Order Chemical Kinetic Complic...mentioning

confidence: 99%