Carbon Screen-Printed Electrodes

These inexpensive screen-printed electrodes (SPEs) have a polyethylene terephthalate (PET) substrate, carbon working and counter electrodes, and a silver/silver chloride (Ag/AgCl) built-in reference electrode.  A blue insulating dielectric material is coated on the PET substrate around the electrodes.  Pine Research offers a Screen-Printed Electrode Cell Starter Kit for working with these SPEs.  Each SPE card can be conveniently plugged into a custom grip mount without the need for banana plugs or alligator cables.  The grip mount is, in turn, fits onto a custom cap which threads onto a disposable 20 mL scintillation vial.

The custom grip contains an edge card connector, where each SPE card is plugged into.  Carbon SPEs are thinner than the ceramic SPEs (0.36 mm vs 0.67 mm); thus, one or more “spacers” are needed to mount the carbon SPE so that it can maintain proper electrical contact with the edge card connector.  Spacers, also made of PET and about a third in length compared to a carbon SPE card, are included with the purchase of carbon SPEs.  It is important to keep the spacer above the solution level, as capillary action will draw electrolyte into the contact area, leading to a possible short of the electrode circuit and eventual corrosion of the edge card connector.

The carbon working electrode comes in either a 2 mm OD circle or a 4 x 5 mm square pattern.  The carbon counter electrode is a large surface area “U”-shape, and the silver/silver chloride reference electrode is a small circle next to the working electrode.