Cyclic Voltammetry

In cyclic voltammetry a three electrode system is needed with a working electrode, where the redox reaction will occur, a counter electrode, to change potential for the working electrode to remain steady, and a reference electrode, to record all voltage values against. As voltages are relative values standards such as the Standard Hydrogen Electrode (SHE) or Ag/AgCl reference electrodes are used as these reference points. The composition of the working and counter electrodes depends on the experiments being performed, but for our purposes carbon working electrodes and platinum counter electrodes were used.

The electrodes need to be submerged in an electrochemical cell following this procedure:

• 25mL of 0.1M pH7 Phosphate Buffered Saline (PBS)
• Place electrodes in solution
• Place lid on cell
• Insert needle and bubble nitrogen or argon gas into the solution for 5 minutes
• Inject test analyte into cell
• Sweep between two vertex points (0-2V vs Reduction of Hydrogen Electrode is a good starting point)
• Sweep at a rate of either 50mV/s or 100mV/s
• If no electrochmistry is observed, i.e: flat line, change the vertex potential to a different range
• Clean up according to laboratory protocols