LASER TRAPPING AND ELECTROCHEMISTRY OF A SINGLE OIL DROPLET IN WATER - ELECTRON-TRANSFER ACROSS THE OIL-DROPLET ELECTRODE INTERFACE

The electrochemistry of ferrocene (FeCp) in a single micrometer-sized nitrobenzene droplet dispersed in water was studied by laser trapping and microelectrochemical techniques. Mass transfer of FeCp, ferrocenium ion, and tetra-n-butylammonium ion between the droplet and water phases accompanied by oxidation of FeCp proceeded across the droplet\water interface. The peak potential of a cyclic voltammogram of FeCp was highly dependent on the potential sweep rate. The potential shift was analyzed by thin-layer electrolysis and the results are discussed in terms of the irreversible electron transfer of FeCp across the droplet\electrode interface and in terms of mass transfer of ion species across the droplet\water interface.