Polishing Screen Printed Electrodes

In this note we discuss polishing electrodes and have a video where we apply the technique to screen printed electrodes (SPEs).

Click the button for a case study on cleaning with solvents.


Mechanical polishing

The working electrodes (WEs) of a selection of ZP electrodes can be mechanically polished by applying a slurry from the Zimmer and Peacock Electrode Polishing Kit onto the WE and gently polishing in a circular motion upon a polishing cloth. The adjacent figure depicts a generic ZP electrode with the slurry applied to the active electrode site. 

How to use the kit

 

  1. Prepare the glass plate, and put a few drops of polishing diamond on a wetted diamond polishing pad.
  2. Hold the CV electrode at right angle to the pad, and polish in a circular motion.
  3. Replace the diamond pad to an alumina polishing pad, put a few drops of polishing alumina, and polish the electrode to be mirror surface. Rinse the electrode surface with distilled water, and finish by air drying.
  4. Using a new alumina polishing pad, polish few times the electrode (for removing the alumina particles remaining on the electrode surface). Rinse the electrode surface with distilled water, and finish by air drying.

The kit can be purchased by clicking the button below.

The results of mechanical polishing

The petrochemical behavior of a mechanically polished ZP (M = polished) gold electrode towards hydrogen peroxide compared to an untreated ZP gold electrode (U= unpolished) is described by the voltammogram in the adjacent figure. The solid blue and dashed yellow lines represent the response of the M and U WEs, respectively, in PBS containing no hydrogen peroxide. The dotted purple trace and the dash-dotted orange trace represent the response of towards 1 mmol L-1 hydrogen peroxide in PBS solution for U and M, respectively. The scans were done versus the on-board Ag/AgCl RE of the ZP electrode system at a scan rate of 10 mV/s.

There is a  difference between the U and the M when there is no hydrogen peroxide present, baseline signal. The mechanically treated WE exhibits a greater magnitude response towards hydrogen peroxide. A shift in the anodic peak from about 0.5 V to 0.4 V is observed when comparing the U and the M in response to hydrogen peroxide. Also, the oxidation of hydrogen peroxide seems to happen at a faster rate at a lower voltage for the M. The build-up towards a cathodic peak (out of the range of this voltage scan range) seems to happen at a lower negative voltage for the M.

www.zimmerpeacock.com 2019