Metallic nanoparticles (NPs) play an important role in molecular sensing and alternative energy harvesting, conversion and storage. Understanding electrocatalytic properties of metal NPs on single particle level is crucial for unfolding their structure-function relationship. Preparation of single metal NP electrode or isolated NPes to be resolved optically is a feasible strategy to study catalytic and electrochemical properties of single nanoparticles. We will present an optically transparent ultramicroelectrode (UME) method for studying electrocatalytic property of single Au NPs with combined methods of electrochemistry and dark field light scattering (DFS) and electrogenerated chemiluminescence (ECL). Electrodeposition, photolithography, ion mill and oxygen plasma etching are utilized to fabricate Au NP modified indium tin oxide (ITO) UME. In addition, we developed a new strategy to fabricate a nanoelectrode modified with a single gold nanoparticle (Au NP) using combined methods of electrodeposition and electrochemical etching. By varying the electrochemical deposition time and potential amplitude tips with different Au NP sizes less than 1um in diam. were obtained. In-situ imaging of Au NP formation on tungsten tip was obtained using dark field scattering microscopy. As prepared nanoelectrodes are also characterized with scanning electron microscopy (SEM), cyclic voltammetry (CV), as well as electrogenerated chemiluminescence.

Single nanoparticle spectroelectrochemistry for understanding locally catalyzed redox reactions at the nanometer scale

256th National Meeting (2018)

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