Multibarrel Electrodes for Multipurpose Electroanalysis

Small volume entities, such as aerosols, microdroplets, and cells, hold many truths of nature that are only recently being discovered. For example, researchers are finding that the reaction rates of certain entities are orders of magnitude larger in microdroplets than in bulk solutions, and that this effect scales with droplet size. Thus, the heterogeneity within populations of each of these environments require analysis at the single entity level. In order to probe these systems, new measurement tools must be developed. To this end, electrochemistry offers a sensitive, rapid, and affordable platform with which to make these kinds of measurements. In addition, electrochemistry can be adapted to detect a vast array of analytes, from environmental contaminants like per- and polyfluoroalkyl substances (PFAS, i.e. “Forever Chemicals”), to heavy metals like lead, to energetics like 2,4,6-trinitrotoluene (TNT). Aerosol sampling can be performed using a modified technique called Particle-Into-Liquid Sampling for Nanoliter Electrochemical Reactions (PILSNER). Building upon this, entire electrochemical cells can be miniaturized into a single probe (10s-100s of micrometers in diameter) for single aerosol detection, as well as single cell and microdroplet electroanalysis. Using fundamental principles and mathematical solutions, these probes can also be used to investigate temperature change and ice nucleation in microdroplets. This dissertation demonstrates the utility of electrochemistry to probe a wide range of small volume entities.