Analytical Sciences


Abstract − Analytical Sciences, 23(9), 1041 (2007).

Potential-Modulation Spectroscopy at Solid/Liquid and Liquid/Liquid Interfaces
Hirohisa NAGATANI and Takamasa SAGARA
Department of Applied Chemistry, Faculty of Engineering, Nagasaki University, Bunkyo 1-14, Nagasaki 852-8521, Japan
Potential-modulation spectroelectrochemical methods at solid/liquid and liquid/liquid interfaces are reviewed. After a brief summary of the basic features and advantages of the methods, practical applications of potential-modulation spectroscopy are demonstrated using our recent studies of solid/liquid and liquid/liquid interfaces, including reflection measurements for a redox protein on a modified gold electrode and fluorescence measurements for various dyes at a polarized water/1,2-dichloroethane interface. For both interfaces, the use of linearly polarized incident light enabled an estimation of the molecular orientation. The use of a potential-modulated transmission-absorption measurement for an optically transparent electrode with immobilized metal nanoparticles is also described. The ability of potential-modulated fluorescence spectroscopy to clearly elucidate the charge transfer and adsorption mechanisms at liquid/liquid interfaces is highlighted.