Low-cost, thin-film, mass-manufacturable carbon electrodes for detection of the neurotransmitter dopamine

A flexible, thin-film carbon electrode is reported for detection of the key neurotransmitter dopamine using standard electroanalytical techniques of cyclic voltammetry, differential pulse voltammetry and square wave voltammetry. The thin-film electrode has been explored as a possible low-cost solution to detect low concentrations of dopamine and its performance has been compared with a commercially available screen printed carbon electrode. It was found that the thin-film electrode is more sensitive than the screen printed electrode, and can faithfully detect dopamine between 50 pM and 1 mM concentrations. The electrode provides a limit of detection of ~50 pM, displays good selectivity between dopamine and ascorbic acid, and is able to show a level of differentiation between the two compounds in terms of peak currents as well as oxidative potentials at physiologically relevant concentrations. This is in contrast to the screen printed electrode which is unable to discriminate between dopamine and ascorbic acid at the same concentrations. The key advantages of the presented electrode system are its low-cost, flexible substrate, and the ability to achieve very low levels of dopamine detection without requiring any electrode surface modification steps, a key factor in reducing fabrication costs and overall device complexity.