Construction of Ag/AgCl Reference Electrode from Used Felt-Tipped Pen Barrel for Undergraduate Laboratory

A reference electrode is one of the prerequisites of electrochemical investigations. Many electrodes are commercially available but are expensive and prone to accidental breakage by students. Here we report a simple, easy-to-fabricate, inexpensive, reliable, unbreakable, and reproducible Ag/AgCl reference electrode. The empty barrel of a felt-tipped pen is used for this purpose. The constructed electrode is similar in performance to the commercially available electrodes and has long-lasting stability. The procedure is expected to encourage undergraduate students to design their own reference electrodes for the electrochemical experiments.