Voltammetric Determination of Tumor Biomarkers using Flow Injection Analysis with Amperometric Detection
Abstract
Three tumor biomarkers (homovanillic acid, vanillylmandelic acid, and 5-hydroxyindole-3-acetic acid) have been determined by flow injection analysis with amperometric detection at screen-printed carbon electrodes in optimum medium of Britton-Robinson buffer (0.04mol lMINUS SIGN 1, pH = 2.0). Dependences of the peaks current on the concentration of biomarkers were linear in the tested concentration region from 0.05 to 100 μmol lMINUS SIGN 1, with the limits of detection of 0.065μmol lMINUS SIGN 1 for homovanillic acid, 0.053μmol lMINUS SIGN 1 for vanillylmandelic acid, and 0.033 μmol lMINUS SIGN 1 for 5-hydroxyindole-3-acetic acid (calculated from heights), and 0.024 μmol lMINUS SIGN 1 for homovanillic acid, 0.020μmol lMINUS SIGN 1 for vanillylmandelic acid, and 0.012 μmol lMINUS SIGN 1 for 5-hydroxyindole-3-acetic acid (calculated fromareas), respectively.