A film electrode composed of micron-diamond embedded in phenolic resin derived amorphous carbon for electroanalysis of dopamine in the presence of uric acid

Levels of dopamine (DA) in the human body is directly related to an individual’s health status. It is crucial to detect DA via economical and effective means, especially when it coexists with other molecules. A self-supporting array-like electrode composed of micron-diamond particles distributed in amorphous carbon (AC) matrix (D/AC) was synthesized by vacuum annealing the mixture of phenolic resin (PR) and micro-diamond. During the annealing process, the PR was converted to AC. The AC was divided into micron-level areas using micron-diamond particles to obtain an array-like electrode, which improved the response of electroanalysis signals. The D/AC exhibited a low limit of detection for DA (0.238 μM), which was attributed to the array-like structure. Moreover, outstanding selectivity towards DA on D/AC in the presence of uric acid was confirmed, and the evident peak potential differences (300 mV) facilitated detection of DA. The detection limit of DA on D/AC in the presence of uric acid was 0.334 μM. Accordingly, D/AC may be suitable as biosensor candidate due to its decent stability, reproducibility and selectivity.