Binary Mixture of Lanthanide Metal Doped ZnO Nanorod: f-MWCNT Nanocomposite for Simultaneous and Selective Determination of Vitamins B2 and B6

An electrochemical sensor using lanthanide element Gadolinium doped Zinc oxide and functionalized Multiwalled Carbon Nanotube (Gd-ZnO:f-MWCNT) fabricated electrode was presented for the simultaneous determination of vitamins (Riboflavin (VB₂) and Pyridoxine (VB6)). The nanocomposite was characterized by FESEM, EDS, XRD and FTIR techniques. The CV, EIS and DPV techniques were used to evaluate the electrochemical properties of the nanocomposite. Under optimum conditions, the peak current of VB₂ and VB6 are linearly proportional to its concentration in the range from 0.05 to 10 μM and the estimated detection limits were 0.009 and 0.001 μM for VB₂ and VB6 respectively. The sensitivities calculated were 0.94 μA nM-1 cm-2 (VB₂) and 1.43 μA nM-1 cm-2 (VB6). In addition, the proposed electrode was exhibited high selectivity, reproducibility, as well as long-term stability for the determination of vitamins. Finally, the vitamins contained in pharmaceutical formulation and commercial orange juice has been determined by the proposed sensor and the obtained results were validated with HPLC.