Electrochemical detection of phenacetin with graphite/boron-doped diamond electrode grown at high methane concentration

We have developed a composite electrode containing boron-doped diamond and high graphite content (HGBDD) by microwave plasma chemical vapor deposition system at high methane concentration. The electrode is applied to test the trace level of phenacetin. Scanning rate studies have exhibited that electrochemical oxidation is controlled by adsorption with scanning speed ranging from 20 to 100 mV s−1, while electrochemical oxidation is controlled by diffusion process at a higher scanning rate. Voltammetry of phenacetin researched on the HGBDD electrode reveals the redox mechanism of phenacetin. It is found that the HGBDD has a high current response with a sensitive detection limit of 0.058 μM and a wide linear detection range of 0.5 μM - 400 μM. The high performance could be attributed to the presence of a higher carrier concentration. Through the density functional theory, the graphite on the diamond surface could adsorb phenacetin stronger and provide more active sites for the redox reaction. Due to the unique properties, the electrode shows stability, repeatability, and accuracy for detecting phenacetin.