Characterization and electrochemical behavior of spherical boron-doped diamond film electrode

The boron-doped diamond film electrode was prepared on the tungsten carbide (WC) sphere using the microwave plasma chemical vapor deposition method. Two electrodes of different sizes were obtained by the encapsulation of the diamond coated spheres. A flexible lead wire was utilized instead of the rigid connection as usual. Scanning electronic microscopy, Raman spectroscopy, and electrochemical measurements were employed to characterize the morphology, the composition of the films, and electrochemical behavior, respectively. These electrodes have a wide potential window of 3 V in phosphate buffer saline solution. The electrode with a diameter of 800 μm exhibits a low dopamine detection concentration of 10 μmol l−1, while the electrode with a diameter of 200 μm indicates the faster electrode response and the higher sensitivity with a microelectrode diffusion mode. A WC sphere with the boron-doped diamond film is expected to be used for the electrode to ensure full contact with the organism.