The transduction element of an electrochemical biosensor is an electrochemical cell where the main component is commonly a working electrode. A three electrode format (working, auxiliary, and reference) is commonly employed in a potentiostatic system, while a two electrode format (working and auxiliary) is often used for conductometry and electrochemical impedance spectroscopy (EIS). Electrodes can be fabricated from multiple materials and using various manufacturing processes. An electrode is an electronic conductor through which charge is transported by the movement of electrons and holes (Bard and Faulkner, 2000). Electrodes are thus fabricated from conducting and semiconducting materials, including metals, such as gold (Au), and nonmetals, such as carbon. Manufacturing processes can be used to fabricate electrodes of various sizes, including bulk structures (greater than 1 mm) and micro- and nano-structures. As a result, electrodes can be classified by type and form of material, manufacturing process, and design. Electrode designs can be classified by form factor, which includes planar, wire, nanostructured, or array-based. The material, fabrication approach, and design affect the electrode's structure and properties, which ultimately determine the biosensor's performance, including sensitivity, selectivity, limit of detection (LOD), and dynamic range. They also influence the biosensor's cost, manufacturability, disposability, and measurement capabilities.