Chemical sensing conductometric sensor

Conductometric (resistive) sensors have a simple structure, and their operating principle is based on the fact that their electrical conductivity (or electrical conductance) can be modulated by the presence or absence of some chemical species that comes in contact with the device (Wohltjen et al. 1985). The basis of the operation of conductometric sensors is the change in resistance under the effect of reactions (adsorption, chemical reactions, diffusion, catalysis, swelling) taking place on the surface or in the bulk of the sensing layer. The chemical species interact with the sensitive layer and thus modu-... 

Metal oxides are among the most used active materials for conductometric chemical sensors. They have a wide variety of electrical properties spanning from insulator to quasi metallic behavior. The discovery of their sensing properties was made more than five decades ago, thereafter the interest of researchers was focused on nanostructured materials. These materials may give a greater modulation of the electrical properties for the interaction with the surrounding atmosphere thanks to the higher surface to volume ratio. 

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