A gas sensor comprises a substrate layer; a pair of interdigitated metal electrodes, said electrodes include upper surfaces, the electrodes selected from the group consisting of Pt, Pd, Au, Ir, Ag, Ru, Rh, In, Os, and their alloys. Descriptive item information is provided to a consumer on a mass media storage device. In at least some embodiments, a user can select the item and navigate the list via a single interaction.