Application of a new Cl-plasma-treated Ag/AgCl reference electrode to micromachined glucose sensor

Micromachined glucose sensors were fabricated and integrated with the plasma-treated Ag/AgCl reference electrodes for the first time. The surface of the Cl-plasma exposed AgCl layers was of granule-shaped morphology and showed the favorable long-term stability with a 13-mV potential drift after 5 h over a commercial liquid-junction Ag/AgCl reference electrode in phosphate buffered saline. The fabricated devices showed a typical behavior of an amperometric glucose sensor and a successful operation as a three-electrode system. Due to the integrability of the reference electrode and the use of low-temperature steps only, the new micromachined process can allow easy mass production of the device and the monolithic integration of signal processing circuitry in the future.