(Invited) Fluorescence-Enabled Electrochemistry of Single Molecules and Nanoparticles

We are developing a new electrochemical detection method to study redox properties of single molecules. This method relies on the use of fluorescence to amply the signal of single electron-transfer events at the electrode/solution interface. A bipolar electrode mechanism is used to couple a redox reaction of interest to a fluorogenic reaction.  The oxidation or reduction of the redox species at the bipolar electrode results in the generation of a highly fluorescence product at the opposite pole of the same bipolar electrode, which is optically monitored with total-internal reflection fluorescence microscopy (TIRFM). The use of this method allows one to resolve single redox events in an electrolyte solution at room temperature.  In this talk, I will first discussion some of our recent results on the detection of single redox molecules, including ferrocene and ferricyanide, and single nanoparticles. I will then discussion some of our new experiments on electrochemical coupling at single nanoparticles. I will also discuss a couple of experiments focusing on imaging and resolving single redox events with very large electrochemical arrays.