Zinc Ferrite Nanostructure/Multi-Walled Carbon Nanotubes (Zfo/Mwcnts) Nanocomposite As Sensor For Homovanillic Acid Detection In Urine Samples For Cancer Therapy Monitoring

The present work describes a novel electrochemical sensor based on the combination of zinc ferrite nanostructure/multi-walled carbon nanotubes (ZFO/MWCNTs) for sensitive voltammetric determination of homovanillic acid (HVA) in urine samples for diagnosis of neuroblastoma. Different ferrite nanostructures doped with Zn, Cu or Mn, were synthesized and characterized with XRD, SEM, TEM and, FTIR. ZFO/MWCNTs nanocomposite showed an excellent electrocatalytic activity towards the oxidation of HVA with a linear response in the concentration range from 0.415 to 3.225 x 10(-6) mol L-1 and the detection limit of 0.148X 10(-6) mol L-1. The high resolution between the HVA voltammetric peak and those for uric acid, ascorbic acid, and dopamine introduced the fabricated sensors as an efficient analytical tool for submicromolar voltammetric determination of homovanillic acid in urine samples without prior pretreatment or pre-concentration step. Moreover, the electrode reaction mechanism was studied electrically and correlated with the molecular orbital calculations.