Next-generation nanoelectrochemical tools

Description:
Nanoelectrochemical tools, such as electrochemical imaging, nanoparticle collisions, nanopores, and nanoelectrodes, have allowed electrochemists to address questions that are inaccessible to macroscale techniques. They allow us to probe faster processes and shorter-lived species, assess spatial heterogeneity over electrode surfaces, and measure nanoscale entities (e.g., nanoparticles) one-at-a-time assess heterogeneity. While measuring single entities with electrochemical tools is now routinely reported, it is not without challenges. An ideal nanoelectrochemical measurement would maintain all of the benefits of macroscale measurements – the ability to pre- and post- analyze a sample with complementary physical techniques and the ability to probe a single sample with a suite of electrochemical techniques – and those of nanoscale techniques (see above) and should be able to do so with a high-throughput in a (semi-) automatic way. In this work we will describe our efforts to attain such ideals in a scanning electrochemical cell microscope (SECCM). This nanoelectrochemical tool uses the meniscus at the end of an electrolyte filled mobile nanopipette to sequentially form nanoelectrochemical cells over a surface. Harnessing electrokinetic phenomena, we manipulate the contents of this cell, allowing one to characterize a single nanoentity in different conditions (e.g., at different pHs or with a reaction substrate and intermediate).