Enhanced selectivity of boron doped diamond electrodes for the detection of dopamine and ascorbic acid by increasing the film thickness

[Display omitted] •BDD electrodes with different thickness have been fabricated.•BDD electrodes are used for simultaneous detection of DA and AA.•Anodic pretreatment enhance the separation of DA and AA oxidation peak potential.•Thicker BDD electrode show better performance for DA detection coexisting with AA. In this paper, boron doped diamond (BDD) with different thickness were prepared by hot filament chemical vapor deposition. The performance of BDD electrodes for detecting dopamine (DA) and ascorbic acid (AA) were investigated. Scanning electron microscopy and Raman spectra reveal the grain size increases and the film quality improves with the increase of film thickness. Electrochemical test show that the transfer coefficient in [Fe3 (CN) 6]3−/4− redox system increases with the increase of the film thickness. The results of selectivity and sensitivity for DA mixed with AA detection show that 8h-BDD and 12h-BDD electrodes possess well selective separated oxidation peaks of DA and AA, and the 12h-BDD electrode exhibits optimal sensitivity until the DA concentration drops to 1μM.