Ewha Womans University · Materials Science
Professor Byung-Kwon Kim's research lab specializes in single-entity electrochemistry, focusing on the electrochemical detection and analysis of individual micro- and nanoscale entities such as emulsion droplets, platelets, and hydrazine molecules. The lab pioneers innovative electrochemical techniques—particularly using ultramicroelectrodes (UME)—to study collision events at the single-particle level, enabling precise measurements of concentration, size distribution, and redox behavior. Key research directions include the development of selective electrochemical sensors for environmental and biomedical applications, such as hydrazine detection in water and serotonin quantification in single platelets, as well as the electrochemistry of complex systems like Pickering emulsions and water-in-oil emulsions without relying on redox probes. The lab’s work bridges fundamental electrochemistry with practical applications in environmental monitoring, clinical diagnostics, and materials science.
Figures are computed from collected data and may differ slightly.
We report an electrochemical study of the collisions of single droplets in an emulsion by two methods. In the first method, an electroactive redox species, for example, ferrocene, inside a toluene-in-water emulsion droplet (but not in the continuous phase) is measured by chronoamperometry during a collision with an ultramicroelectrode (UME). Here, a blip or spike type of collision signal is observed, representing electrolysis of the droplet contents. In the second method, electrochemical oxidati
We report here the electrochemistry of emulsion droplets by observing single emulsion droplet collisions with selective electrochemical reduction on an ultramicroelectrode (UME). With appropriately applied potentials at an UME, we can observe the electrochemical effects of single collision signals from the complete electrolysis of single emulsion droplets, or selective electrolysis of redox species in single emulsion droplets. This was observed with nitrobenzene (NB), 7,7,8,8-tetracyanoquinodime
This research introduces a method to directly detect serotonin in a single platelet through single-entity electrochemistry. Platelets isolated from human blood were analyzed by cyclic voltammetry and current-time measurements. When a single platelet collides with an ultramicroelectrode, serotonin inside the platelet is oxidized at the electrode surface, and an anodic current peak is consequently observed during measurement. The concentration of serotonin can be determined by integrating this pea
We have developed a simple and selective method for the electrochemical detection of hydrazine (HZ) using poly(dopamine) (pDA)-modified indium tin oxide (ITO) electrodes. Modification with pDA was easily achieved by submerging the ITO electrode in a DA solution for 30 min. The electrocatalytic oxidation of HZ on the pDA-modified ITO electrode was measured by cyclic voltammetry. In buffer solution, the concentration range for linear HZ detection was 100 µM-10 mM, and the detection limit was 1 µM.
Single-entity analysis is an important research topic in electrochemistry. To date, electrode collisions and subsequent electrode-particle interactions have been studied for many types of nano-objects, including metals, polymers, and micelles. Here we extend this nano-object electrochemistry analysis to Pickering emulsions for the first time. The electrochemistry of Pickering emulsions is important because the internal space of a Pickering emulsion can serve as a reactor or template; this leads
Abstract 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 f
Herein, a study on a new lower critical solution temperature (LCST) polymer in an organic solvent by an electrochemical technique has been reported. The phase-transition behavior of poly(arylene ether sulfone) (PAES) was examined on 1,2-dimethoxyethane (DME). At a temperature above the LCST point, polymer molecules aggregated to create polymer droplets. These droplets subsequently collided with an ultramicroelectrode (UME), resulting in a new form of staircase current decrease. The experimental
Open papers in the app to read, cite, and organize with AI.
