To investigate whether the effect of the analysis is concentration-dependent, a series of concentrations of 2CPTZ were prepared (Table ). The experiment was designed to run at a scan rate of 0.20 Vs -1 with a step potential of 0.00244 V, sweeping from the initial and stop potential of 0 V. The step-up current responses in increasing concentration of 2CPTZ show a proportional increase in faradaic current (Table ). The peak current (ip) increases with increasing analyte concentration because there are more redox-active species available to undergo oxidation at the electrode surface, and with increasing the scan rate (Table ), the electrode potential changes more rapidly, and the rate of electron transfer reactions increases, leading to a larger peak current. These are consistent with the Randles-Sevcik equation and indicate the diffusion-controlled redox process.