Single Microcystis Detection Through Electrochemical Collision Events on Ultramicroelectrodes

This study introduces the electrochemical detection of a single microcystis on an Au ultramicroelectrode based on single-entity electrochemistry. The electrochemical collisions occur when the microcystis is adsorbed on the electrode surface. This hinders the oxidation of the electroactive redox species in the solution, thus making the current decrease like a staircase. In this experiment, the current decrease caused by the collision which requires an appropriate concentration of the redox species and initial potential, providing information on migration effect by zeta-potential, and collision frequency. Comparison of the simulation results of the finite element method and the experimental results suggested that the staircase current decrease caused by the microcystis can occur due to collision not only on the electrode surface but also on the surrounding regions of the electrode surface (i.e., the active area). These results suggest various applications of the single-entity cell detection using the electrochemical method for real-time analysis.