Conductive properties are optimized in conducting polymers, made up of organic units and metal ions, by tailoring the position of metal ions with respect to conductive pathways or by selecting components such that the redox potential of organic units and metal ions differs by no more than 250 mV. Very small devices, and articles in which a high percentage of metal ions are redox active, are provided. Articles that can serve as sensors include metal ions with at least one free reactive site that can accommodate an analyte for conductivity change detection. Chemoresistive devices, field effect transistors, and signal amplifiers are provided.