Voltammetric Determination of Tumor Biomarkers for Neuroblastoma (Homovanillic Acid, Vanillylmandelic Acid, and 5‐Hydroxyindole‐3‐acetic Acid) at Screen‐printed Carbon Electrodes

Abstract Three tumor biomarkers (homovanillic acid (HVA), vanillylmandelic acid (VMA), and 5‐hydroxyindole‐3‐acetic acid (5‐HIAA)) have been determined by differential pulse voltammetry (DPV) at screen‐printed carbon electrodes (SPCEs). As an optimum medium for all three analytes, Britton‐Robinson buffer (0.04 mol ⋅ L −1 , pH 3.0) was used. Dependencies of the peak current on the concentration of a biomarker were linear in the concentration range from 0.2 to 100 μmol ⋅ L −1 for all the tested compounds, with the limits of quantification 0.8 μmol ⋅ L −1 for homovanillic acid, 0.2 μmol ⋅ L −1 for vanillylmandelic acid, and 0.4 μmol ⋅ L −1 for 5‐hydroxyindole‐3‐acetic acid. Moreover, it was verified that the newly developed methods can be used for simultaneous determination of HVA and VMA in mixture.