Comparison of Carbon Nanomaterials for Simultaneous Detection of Neurotransmitters in the Presence of Interfering Species

The main hurdle in simultaneous analysis of dopamine and serotonin is not only their similar detection potential but also the polymerization of dopamine at physiological pH, which results in sensitivity loss. In this work, we investigated glassy carbon electrodes and electrodes modified with carbon black, graphene oxide, and carbon nanodots in terms of their ability to detect 5 neurobiologically relevant analytes (dopamine, serotonin, epinephrine, norepinephrine, and 3,4‐dihydroxyphenylacetic acid). We proved that simultaneous detection of dopamine and serotonin in the presence of uric and ascorbic acids is possible on electrodes modified with carbon black and graphene oxide, both in buffer solution and cell medium. Graphene oxide‐modified electrodes have shown the highest sensitivity towards all tested neurotransmitters. Moreover, a considerable shift of epinephrine, norepinephrine, and 3,4‐dihydroxyphenylacetic acid peaks towards more negative potentials was observed for electrodes modified with carbon black and graphene oxide as compared with glassy carbon electrodes. Electrodes covered with carbon nanodots were proven inappropriate due to their surface functionalization with ethylenediamine. Glassy carbon electrodes and electrodes modified with carbon black, graphene oxide, and carbon nanodots were analyzed towards the detection of five neurobiologically relevant analytes (dopamine, serotonin, epinephrine, norepinephrine, and 3,4‐dihydroxyphenylacetic acid). It was shown that graphene oxide and carbon black are suitable for the determination of neurotransmitters in the presence of interfering species, such as uric and ascorbic acid.