Catálogo de Investigaciones | 2012-2013

35 CATÁLOGO DE INVESTIGACIONES | AÑO ACADÉMICO 2012-2013 Electrochemical Reactivity of Biologically Active Quinonoid Molecules at Single Crystal Platinum Electrodes Over decades, quinonoid redox couples have been used as model organic redox systems. This group of molecules plays a key role as electron-transfer and proton-carrier agents in biological systems, where it is involved in photosynthesis and cell respiration. From a pharmacological standpoint, quinonoid molecules have been associated to antitumor AL and antibiotic activity. This group of molecules is also used as electron-transfer mediators in electrochemical DNA biosensors. For that reason, the rates of electron transfer of the Q/HQ couple have been extensively studied in both aqueous and organic solutions. The structure and composition of electrode/electrolyte interfaces can alter the electron-transfer kinetics of solution redox species. During early studies, little attention was given to the role played by electrode surface composition or by 2Dimensional and 3Dimensional structure in controlling the electron-transfer kinetics of the Q (ads) /HQ (aq) redox couple. In this project it is proposed, to continue ongoing studies about the electrochemical reactivity of quinonoid molecules at well-defined Pt single-crystal. The reactivity will be studied as a function of supporting electrolyte composition, electrode potential, surface composition and surface structure to establish the parameters that control the nature of adsorbate/surface bonding as a prerequisite to understand, control and predict electrochemical reactivity at those interfaces. The objective will be to study reductive desorption of hydroquinone-derived adlayers (Q (ads) ) from nearly defect-free single crystal platinum surfaces to correlate changes in electrode structure to changes in the dynamics of chemisorption at solid-liquid interface. The proposed research will combine Classical Electrochemical Methods and electrode surface coordination model to develop an atomic-level understanding of the electrochemical reactivity quinones at well-defined electrode interfaces. The interest is rooted to the belief that this information will be useful in the development of an improved theoretical understanding of these biologically active molecules. josé e. mercado adrover proyecto especial mentor: dra. margarita rodríguez lópez electro chemistry quinonoid-compounds platinum-electrodes