The study of single-entity electrochemistry on ultramicroelectrodes, also known as Nano-impact electrochemistry or Single-particle collision, has recently gained attention. This method allows for the analysis of various properties of particles in solution, such as diffusion coefficient, particle composition, size distribution, and concentration. Our group has also explored the use of this technique on soft entities like emulsions, bacteria, red blood cells, and platelets. By monitoring the increase or decrease in current signal when a single-entity collides with the electrode surface, we can gain insights into the properties and composition of the particles. For example, if there is a high concentration of redox constantly reacting in the UME and red blood cells collide with the electrode surface, we can observe a decrease in the current. As another example, when platelets collide with electrodes, the concentration of serotonin present in platelets can be analyzed. In this case, an increase in the current signal is observed. The increase or decrease of the current signal depends on the characteristics of the single-entity and the composition of the solution. As such, single-entity electrochemistry is a useful way to obtain important information about various entities.