Cyclic voltammetry

high-resolution terminology - matching measurements at high-resolution

Cyclic voltammetry

Description

Cyclic voltammetry (CV) is a type of electrochemical measurement which is applied in the Q-Module as a quality control step to determine the redox potential of Coenzyme Q in the specific experimental conditions used. In cyclic voltammetry, the Q-Sensor with the three-electrode system is used to obtain information about the analyte (CoQ) by measuring the current (I) as the electric potential (V) between two of the electrodes is varied. In CV the electric potential between the glassy carbon (GC) and the Ag/AgCl reference electrode changes linearly versus time in cyclical phases, while the current is detected between GC and platinum electrode (Pt). The detected current is plotted versus the applied voltage to obtain the typical cyclic voltammogram trace (Figure 1). The presence of substances that are oxidized/reduced will result in current between GC and Pt, which can be seen as characteristic peaks in the voltammogram at a defined potential. The oxidation or the reduction peak potential values are used to set the GC (integrated into the Q-Sensor) for a separate experiment to measure the Q redox state of a biological sample. The oxidation and reduction peak potentials can be influenced by 1) the respiration medium, 2) type of CoQ, 3) polarization window, 4) scan speed, 5) number of cycles, 6) concentration of the analyte (CoQ),and 7) initial polarization voltage. For further information, see: MiPNet24.12 NextGen-O2k: Q-Module.

Abbreviation: CV

Figure 1. Cyclic voltammogram of Coenzyme Q2 measured with the Q-Module. Measurements were carried out in non-stirred MiR05-Kit medium, at 37 °C using the NextGen-O2k. Initial potential: +30 mV, polarization window: between -500 mV and +500 mV, scanning speed: 100 mV/s, gain: 1; 30 µM Q2 was used for each test. The oxidation peak potential shows the maximum rate of quinol oxidation and the reduction peak potential is the point of maximum rate of quinone reduction.

Cyclic voltammetry is part of the Q-Module and the NextGen-O2k project

The Q-Module allows for monitoring of the redox state of electron transfer-reactive coenzyme Q at the Q-junction using the specific Q-Stoppers with the integrated three-electrode system and the modified electronics of the NextGen-O2k. Cyclic voltammetry is used for quality control and for defining the polarization voltage applied during Q-redox measurements.

Reference:

• Komlódi T, Cardoso LHD, Doerrier C, Moore AL, Rich PR, Gnaiger E (2021) Coupling and pathway control of coenzyme Q redox state and respiration in isolated mitochondria. Bioenerg Commun 2021.3. https://doi.org/10.26124/bec:2021-0003

Communicated by Komlodi T, Cardoso LHD 2020-07-28

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Coenzyme Q

» Coenzyme Q

» Quinone, Ubiquinone Q; oxidized

» Quinol, Ubiquinol QH₂; reduced

» Semiquinone

» Coenzyme Q2

» Q-redox state

» Q-pools

Mitochondrial pathways, respiratory Complexes, and Q

» Q-cycle

» Q-junction

» Convergent electron flow

» NS-pathway

» FNS

» FNSGp

» N-pathway

» Reverse electron flow from CII to CI

» CI

» Rotenone

» Amytal

» Piericidin

» S-pathway

» CII

» Malonate

» F-pathway

» CETF, Electron-transferring flavoprotein complex

» Gp-pathway

» CGpDH, Glycerophosphate dehydrogenase complex

» CIII

» Myxothiazol

» Choline dehydrogenase

» Dihydro-orotate dehydrogenase

NextGen-O2k and Q-Module

» NextGen-O2k

» Q-Module

» Q-Sensor

» Cyclic voltammetry

» Three-electrode system

General

» Categories of SUIT protocols

» Electron transfer pathway

» Electron-transfer-pathway state

» F-junction

» N-junction