Disruption Dynamics and Charge Transfer of a Single Attoliter Emulsion Droplet Revealed by Combined Fast-Scan Sinusoidal Voltammetry and Short Time Fourier Transform Analysis.

Single-entity electrochemistry has gained significant attention for the analysis of individual cells, nanoparticles, and droplets, which is leveraged by robust electrochemical techniques such as chronoamperometry and cyclic voltammetry (CV) to extract information about single entities, including size, kinetics, mass transport, etc. For an in-depth understanding such as dynamic interaction between the electrode and a single entity, the unconventional fast electrochemical technique is essential for time-resolved analysis. This fast experimental technique is unfortunately hindered by a substantial nonfaradaic response.

Variable Nanoelectrode at the Air/Water Interface by Hydrogel-Integrated Atomic Force Microscopy Electrochemical Platform.

A nanoelectrode with a controllable area was developed using commercial atomic force microscopy and a hydrogel. Although tremendous advantages of small electrodes from micrometer scale down to nanometer scale have been previously reported for a wide range of applications, precise and high-throughput fabrication remains an obstacle. In this work, the set-point feedback current in a modified scanning ionic conductance microscopy system controlled the formation of electrodes with a nanometer-sized area by contact between the boron-doped diamond (BDD) tip and the agarose hydrogel.

Long-Range Electrification of an Air/Electrolyte Interface and Probing Potential of Zero Charge by Conductive Amplitude-Modulated Atomic Force Microscopy.

The structure of an electrical double layer (EDL) at the interface of electrode/electrolyte or air/electrode/electrolyte is a fundamental aspect, however not fully understood. The potential of zero charge (PZC) is one of the clues to dictate the EDL, where the excess charge on the electrode surface is zero. Here, a nanoscale configuration of immersion method was proposed by integrating an electrochemical system into conductive atomic force spectroscopy under the amplitude modulation (AM) mode and agarose gel as the solid-liquid electrolyte.

Chemical electrification at solid/liquid/air interface by surface dipole of self-assembled monolayer and harvesting energy of moving water.

Harvesting energy from water motion is attractive and is considered as a promising component in a microgenerator system for decentralized energy. Recent developments have been shown to rely on spontaneous electrification at the solid-liquid interface, even though the precise mechanism is still under debate. In this paper, we report that the triple-phase boundary of solid/liquid/air can be quantitatively charged by tuning the work function by modifying a self-assembled monolayer (SAM), where a permanent or redox-active dipole controls the polarity and degree of electrification, and by modulating the electrochemical potential of the solution used.