INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
Electrochemical investigations into hostguest interactions of a natural antioxidant compound with beta-cyclodextrin
FABRICIA DA ROCHA FERREIRA; EMANUELLA GOMES DA SILVA; LUCILA P. MÉNDEZ DE LEO; ERNESTO J. CALVO; EDSON DE SOUZA BENTO; MARÍLIA OLIVEIRA FONSECA GOULART; FABIANE CAXICO DE ABREU
PERGAMON-ELSEVIER SCIENCE LTD
Año: 2010 vol. 56 p. 797 - 797
The electrochemical behavior of mangiferin (MGN), a natural antioxidant compound, is examined using cyclic and differential pulse voltammetry in a protic medium on a glassy carbon electrode. The voltammograms exhibit a single irreversible pH-dependent anodic wave with current controlled by adsorption. Complexes of MGN with beta-cyclodextrin (beta-CD) were prepared and their formation was confirmed by UVvis spectroscopy and electrochemical experiments, using a self-assembled monolayer of cyclodextrin on a gold electrode. The association constant of MGN:beta-CD complexes was estimated by the BenesiHildebrand method, based on the spectrophotometric quantification of free beta-CD and by the direct method using cyclic voltammetry and the Langmuir isotherm. PM IRRAS experiments corroborated the inclusion process based on the observation of the corresponding peaks in the spectra of the samples. MGN was quantified using a simple electrochemical method based on a beta-CD incorporated carbon nanotube (CNT)-modified electrode (beta-CDCNT). The presence of beta-CD led to a 10-fold lower detection limit than that obtained with a CNT-modified electrode.