CVD diamond anisotropic film as electrode for electrochemical sensing

The unique electrochemical properties of diamond such as a large working potential window, low background current and prolonged stability make it attractive for applications in electroanalysis. High quality and conductive diamond films are known to exhibit active voltammetric response without the need for surface pretreatment. This paper reports on the design, fabrication and characterization of CVD diamond film for electrochemical sensing. Two types of planar boron-doped diamond electrodes were achieved by plasma enhanced chemical vapor deposition (PECVD) using in situ gas phase doping method. The first utilizes the “as grown” diamond surface with randomly microstructured topology as a planar diamond electrode. The second utilizes a micropatterning technique to produce a well-defined pyramidal diamond tips array with good uniformity control. The fabrication process for the electrodes is described. The diamond microelectrodes were evaluated electrochemically for the detection of ferrocyanide, Fe(CN)64−, using cyclic voltammetry. The results suggest that diamond electrodes can be used in electrochemical sensing application.