The waveform parameters (holding potential, transition potential, switching potential, switching potential duration, and scan rate) of a multi-scan rate sawhorse waveform (MSW) were optimized for the sensitive and selective detection of Trp over Tyr. The original MSW (Figure ) was derived from work published by Sombers and colleagues for the detection of enkephalin using FSCV at CFMs . The first scan rate between the holding potential (A, Figure ) and transition potential (B, Figure ) was held constant at 100 V/s because there are no oxidation or reduction peaks of interest occurring in those potentials. The primary oxidation peak occurs between the transition potential (B, Figure ) and the switching potential (C, Figure ). The scan rate in this potential range was varied (discussed below).