Optimization of Paired Pulse Voltammetry Using Sawhorse Waveform

Abstract

The influence of the reduction process on paired-pulse voltammetry (PPV), which consists of two identical triangle-shaped pulses, was studied in this study by increasing peak potential duration. We propose sawhorse waveform as an optimized PPV waveform for enhancing the responses of PPV on dopamine and serotonin (5-HT). To investigate the influence of the scanning parameters on the reduction process and response of PPV, the responses of dopamine were measured by changing the switching potential (from 1.04 to 1.5V), and scan rates (from 400V/s to 1000V/s) based on triangle shaped PPV. As a result, the oxidation and reduction peak ratio in the response of the primary pulse in PPV decreased in a linear fashion with increases to the duration between oxidation and reduction potential, which lead us to obtain more defined features in the subtracted voltammograms (primary-secondary) in PPV. Based on these results, sawhorse waveform PPV with prolonged switching potential duration was suggested to increase the sensitivity of PPV while maintaining its own advantages, and it is also confirmed in an in vivo experiment. In addition to the dopamine experiments, we also conducted an experiment with serotonin utilizing the N-shaped sawhorse waveform PPV. The subtracted voltammogram in the N-shaped PPV with 1.0V peak and 4ms peak potential duration clearly showed the characteristics of serotonin. In conclusion, PPV waveforms could be optimized to improve the sensitivity of PPV responses by the control of the reduction process.