Electrode Mode Headstage

Heka Patch Clamp Amplifiers – Headstage

Category:

Overview

Cyclic voltammogram in 3-electrode mode using an EPC 10 USB patch clamp amplifier

Most suitable for this measurement is an EPC 10 USB Double patch clamp amplifier.

With the 3-Electrode Headstage the EPC 10 USB can measure the potential difference between a third electrode (reference) and the ground (counter) electrode without having current flowing through the reference electrode. The reference electrode stays in equilibrium! The potential difference is added to the command potential for the working electrode.

With the 3-Electrode Mode Headstage the EPC 10 USB patch clamp amplifier has the performance of a high-end potentiostat/galvanostat with a scan range of +/-2 V (with EPC 10 USB Revision ‘T’).

3-Electrode

Measuring Configuration

Working electrode:

Platinum microdisk electrode with 10 µm electroactive diameter.

Reference electrode:

Ag/AgCl electrode

Counter (GND) electrode:

Platinum

Redox mediator (bath solution):

0.7 mM FcMeOH dissolved in 0.117 M KCl

3E Measure

Cyclic Voltammogram

We have scanned the potential of the working electrode with respect to the reference electrode from 0 mV to 400 mV, then to -200 mV and back to 0 mV with a scan rate of 100 mV/s and recorded the current at the working electrode with a bandwidth of 3 kHz.

Analysis of the CV

The diffusion limiting current is determined as 1.2 nA which describes a microdisc electrode with 10 µm electroactive diameter at a concentration of 0.7 mM. The polarographic half wave potential is detected as +150 mV vs. Ag/AgCl.

3E CV