Custom software WCCV 3.6 software (Knowmad Technologies LLC, Tucson, AZ, USA) was employed for the collection and analysis of data, which includes background subtraction, signal averaging, and digital filtering. Data was filtered using a fourth order Butterworth low pass filter. The cyclic voltammograms (CVs) and i-t (current vs time) plots were stacked over time to create a 2D color plot. The x-axis is time (30 s files unless otherwise stated), the y-axis is potential applied (V), and the color indicates current. The CVs and i-t plots were exported as text files and analyzed in Excel and GraphPad Prism 9. The max currents at the oxidation peak corresponding to Trp oxidation (~1.0 V vs. pseudo Ag/AgCl) were normalized to the geometric surface area of each electrode. Grubbs test was used to remove any outliers and errors were propagated appropriately to combine the different trials from different electrodes. All statistical tests, including Grubbs', t-tests, and one-way ANOVA Dunnett T3 multiple comparison test, were conducted in GraphPad Prism 9. Experimental alpha was set at 0.05.