Unusual metals as electrode materials for electrochemical sensors

Although noble metals are still widely used in electroanalysis, a plethora of different non-conventional metals is now enriching the panorama of materials acting as the electrochemical transducer in sensing systems. In particular, Ti, Mo, W, Fe, Co, Bi, and Sb are discussed here in view of their peculiar physico-chemical properties and of the interesting electrocatalytic activities ascribable to these elements and to the relevant metal oxide ultra-thin films that spontaneously form at the electrode|solution interface. This behaviour, exploitable in electroanalysis for the detection of a number on analytes, is often accompanied by the low price, high resistance to corrosion and to abrasion characterising these materials. These peculiarities encourage the possible use of the cited metals in a wide number of analytical frames, ranging from process control to bio-implantable sensing systems.