Use of interdigitated microelectrode arrays as amperometric transducers and amplifier

An array of six interdigitated thin film platinum microelectrodes made by silicon technology and special analytical procedures will be described. For the analytical use as basic transducer the microelectrode array consists of an assembly of independent microband electrodes. Each microband electrode is 3 Mym width, 1 mm long with an interelectrode space of 1 Mym. The other area is insulated by a silicon nitride layer. The microband electrodes are independently held at desired potentials by means of an recently developed multipotentiostat. Applying the oxidation and the reduction potential of electron mediators to pairs of the interdigitated electrodes a redox cyclisation producing an electrochemical amplification have been realised. This could be demonstrated for the sensitive detection of the reversible redox coupe ferro/ferri cyanide. On the other hand, when the same potential is applied at each electrode of an array, the signal to noise ratio is increased due to a signal accumulation . As a result the measurement can be performed with a better reproducibility. These measuring principles can be attractive for improvement of biosensing in microsystem technology.