Modification of Multi-walled Carbon Nanotubes Composite Paste Electrode with Nanonickel Pentacyanonitrosylferrate and Nickel Oxide Nanoparticles for Non-enzymatic Glucose Determination

A novel non-enzymatic electrochemical sensor with high sensitivity for glucose determination was introduced herein with nickel pentacyanonitrosylferrate (NiPCNF)-modified multi-walled carbon nanotubes (MWCNTs) paste electrode and deposited nickel hydroxide onto paste electrode using NiSO4 solution and H2SO4 as the soft template. The NiO-modified electrode was scanned with cyclic voltammetry (CV) method in alkaline media to obtain Ni(OH)2/NiOOH particles as glucose electrocatalyst. The prepared nickel oxide was then mixed with the paste inside the tube. It was observed that introducing both NiPCNF and NiO could synergistically improve the activity toward electrocatalytic oxidation of glucose with an increase in the accessible active sites and promotion of the electron transport capability. Therefore, the modified electrode did not only exhibit an outstanding electrochemical behavior but also decreased the potential for electrochemical oxidation and enhanced the affinity of the electrode to glucose. Field emission scanning electron microscopy (FESEM) was applied to study the surface morphology of the electrode and prepared NiPCNF powder. After optimizing the condition, the chronoamperometry (CA) technique was applied for glucose determination. Porous-modified electrode, containing both nanomaterials of NiPCNF and NiO, exhibited a vast linear range from 5 µM to 1.95 mM (2.6 orders of magnitude) with a low limit of detection (LOD) of 2.35 × 10-7 ± 1.52×10-8 M (S/N=3) and high sensitivity (2.83 ± 0.17 mA mM-1 cm-2). Finally, the prepared sensor was utilized for glucose determination in the real samples successfully.