Direct Electrolysis and Detection of Single Nanosized Water Emulsion Droplets in Organic Solvent Using Stochastic Collisions

We studied the electrochemical detection of single nanosized water emulsion droplets in organic solution using the electrochemical collision technique on an ultramicroelectrode (UME). In this experiment, the detection system for water droplets does not require any kind of redox species in organic solvent. Only water molecules in the water droplets were considered. When water droplets collided with the UME surface, anodic current spikes were observed in the chronoamperometry, resulting from the electrolysis of water molecules in the water droplets. From the collision frequency and integrated current spike, concentrations and size distributions of water droplets in organic solvent can be determined.