Polymer transducers testing

Significant research work should be undertaken before conducting polymer transducers which can be used in estabhshing fimctional devices, beyond the prototypes built and tested in researeh environments. 

Application of transition metal hexacyanoferrates for development of biosensors was first announced by our group in 1994 [118]. The goal was to substitute platinum as the most commonly used hydrogen peroxide transducer for Prussian blue-modified electrode. The enzyme glucose oxidase was immobilized on the top of the transducer in the polymer (Nation) membrane. The resulting biosensor showed advantageous characteristics of both sensitivity and selectivity in the presence of commonly tested reductants, such as ascorbate and paracetamol. 

Among those several different types of transducers based on CNTs, the CNT-composite electrode, which was the first CNT electrode tested in 1996, is still widely used with different composite materials such as conducting polymers, nanoparticles, sol-gel, etc. The usefulness of these electrodes is based on their high sensitivity, quick response, good reproducibility, and particularly long-term stability. We expect to see continued research activities using CNT-composite electrodes. 

An alternative approach places the Pt electrodes directly on a flexible polymer carrier [80]. Eh Lilly developed a three-electrode transducing system based on a polyimide carrier with electroadsorbed enzyme and a highly oxygen-permeable membrane covering the sensor. Such a system was tested in vivo and published results seem encouraging although the company cancelled the project. 

Preinitialization—An Undisturbed Open Circuit Potential Measurement This step measures, stores, and presents to the screen the interfacial potential of the electroconductive transducer in its electrolyte or test environment. This measurement is made of the complete polymer film relative to a reversible Ag/AgCl, CP electrode that also contacts the electrolyte. The unperturbed open circuit potential is diagnostic of the redox state of the device and conveys information about the integrity of the transducer. 

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