Electrochimica Acta, Vol.97, 231-237, 2013
An electrochemical approach to study water-D(-)fructose interactions
Water-D(-)fructose interactions have been studied for the first time by applying electrochemical technique using a redox-active probe ferrocenecarboxylic acid (FCA). Cyclic voltammetry was employed to study electrochemical behavior of FCA in aqueous solution of cetyltrimethylammonium bromide (CTAB) both in absence and presence of D(-)fructose. A three electrode system with a glassy carbon electrode as working electrode was used for this purpose. The concentrations of CTAB, D(-)fructose and FCA were varied in order to correlate electrochemical responses with the dissolved states to interpret water-D(-)fructose interactions. The anodic and the cathodic peak current, as well as, the apparent diffusion coefficient of FCA in micellar solution of CTAB increase with added D(-)fructose at low concentrations; while a reverse trend is observed at high D(-)fructose concentrations. The additions of D(-)fructose at low concentrations raise the critical micelle concentration (CMC) of CTAB, while high concentrations of D(-)fructose favor micellization. Analyses of experimental results indicate that D(-)fructose at lower concentrations behaves as a structure breaker of the water cluster, while that at higher concentrations acts as a structure maker. We have been able to successfully demonstrate that FCA can serve as a standard electro-active probe for studying the interaction of a non-electro-active guest with water. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords:Ferrocenecarboxylic acid;Cyclic voltammetry;Cetyltrimethylammonium bromide;Critical micelle concentration;D(-)Fructose