Voltammetric Determination of Homovanillic Acid on a Disposable Electrochemical Measuring Cell System with Integrated Carbon Composite Film Electrodes
Abstract
Array of carbon composite film electrodes embedded in 96-well microtitration plate was applied for DPV determination of oxidizable tumour biomarker homovanillic acid (HVA). For the preparation of composite electrodes, graphitic conductive microparticles and nonconductive polystyrene were used.
For the measurement, a buffer of pH 2 was selected as the optimum medium. In this medium, concentration dependences were measured; calculated HVA quantification limit was 0.3 mu mol L-1 and detection limit was 0.1 mu mol L-1.
Sorption of HVA on employed working electrode was examined in order to verify, if the current is influenced by the time period between cell filling and measurement. The sorption was not observed and current was stable even after 10 minutes.