Potential-Modulation Spectroscopy at Solid/Liquid and Liquid/Liquid Interfaces

Spectroelectrochemical analysis of ion-transfer and adsorption of the PAMAM dendrimer at a polarized liquid|liquid interface

“…The spectroelectrochemical cell used in all measurements was analogous to one reported previously [15]. The water|DCE interface with a geometrical area of 0.50 cm 2 was polarized by a four-electrode potentiostat (Hokuto Denko HA1010mM1A).…”

Characterization of Charge-Transfer Kinetics at Organic/Electrode Interfaces Using Potential-modulated Attenuated Total Reflectance (PM-ATR) Spectroscopy

“…Under control of the potential applied to a working electrode, spectral information such as electronic absorption, vibrational absorption, light emission, inelastic scattering, and magnetic resonance of the species undergoing a redox reaction can be measured in situ. [1][2][3][4] Compared to electrochemical methods in which current response is measured as a function of potential, spectroelectrochemical methods enable simultaneous investigation of both the kinetics of electrochemical reactions and the structures of the redox-active species and their intermediates. Another major advantage is that, in principle, the spectral signal originates only from faradaic processes; eliminating the background from non-faradaic processes, i.e., charging and discharging of the electrical double layer, can provide significant improvements in sensitivity and selectivity.…”

“…Potential-modulated attenuated total reflectance (PM-ATR) spectroscopy 13 is a unique form of waveguide-based spectroelectrochemistry that utilizes the electroreflectance (ER) spectroscopic approach developed largely by Niki, Sagara, and coworkers. 2,4 Combining potential-modulation with the ATR geometry enables the measurement of charge-transfer kinetics of monolayer to submonolayer thin films on waveguide electrodes, with selectivity to molecular subpopulations in the film provided by appropriate choice of the applied potential and the wavelength and polarization of light, as described further below. This method has been applied to study a wide variety of electrode-supported materials, including small molecule and polymeric semiconductors, [13][14][15][16][17] proteins, 18 inorganic complexes, 19 and semiconductor nanocrystals.…”

Spectroelectrochemical Characterization of Dendrimer–Porphyrin Associates at Polarized Liquid|Liquid Interfaces

“…The surface sensitive spectroelectrochemical techniques such as potential modulation spectroscopy can provide deeper insights of the interfacial mechanism. 5,6 Dendrimers are unique and nontraditional polymers with a well-defined macromolecular architecture consisting of a core, iterative branch units, and terminal groups. 7,8 The reactivity of the dendrimer can chemically be modified by choosing a variety of functional groups in the periphery moiety.…”