Fabrication and characterization of all-diamond microprobes for electrochemical analysis

Fabrication and testing of all-diamond probes for electrochemical applications is reported for the first time. Polycrystalline diamond was used as the structural material of the probe. In addition, highly boron-doped (resistivity of ~10^-3 Omegacm) diamond thin film was used as the electrode material for electrochemical analysis due to its excellent electrochemical properties and resistance to chemical attack. The diamond probe consists of 8 electrode sites ranging in size from 2 to 150 mum in diameter. The measured electrochemical potential window of the electrode was approximately 2.2 V wide (-0.8 to +1.4 V) in 1M KCI. Electrochemical characterization of the fabricated probe using ferri/ferrocyanide redox couple is also reported.