Figure 2.

A paraffin wax coating stabilizes the phenolic insulation at the sensor tip, improving electrochemical performance. A) Dopamine redox activity was not observed when the electrode was fully coated in paraffin. B) Electrochemical conditioning effectively removed the wax from the exposed portion of the fiber, enabling quantification of dopamine. C) Normalized oxidation current collected in response to 1-μM dopamine injections over a 3-h time course (n = 3 electrodes, standard deviation). Data were normalized to the first injection. D) Representative voltammograms for 2-μM dopamine collected using a range of scan rates.