Abstract
Free-standing porous boron-doped diamond (fs-pBDD) was successfully fabricated and employed as a flowthrough working electrode in flow injection analysis (FIA) experiments for the first time. fs-pBDD was fabricated by microwave plasma enhanced chemical vapour deposition growth of BDD on a SiO2 nanofiber template spin coated onto a silicon substrate in a multistep process, before being released by wet chemical etching of the silicon substrate. By means of cyclic voltammetry, the effective surface area of the fs-pBDD electrode was estimated to be 30.1 mm2.
Fundamental performance parameters of the fs-pBDD electrode in an FIA system were determined utilising [Ru(NH3)6](3+/2+) redox probe. A detection potential of -0.3 V and the flow rate of 1.0 mL min(-1) were selected as optimal and were further employed for recording concentration dependence, which was linear from 5 µmol L(-1) to 750 µmol L(-1).
Limits of detection and quantification were assessed as 1.6 µmol L(-1) and 5.3 µmol L(-1), respectively. The obtained results thus proved functionality of the developed fs-pBDD as a perspective electrode material for use as an electrochemical detector for liquid-flow techniques.