Non-Enzymatic Glucose Sensors for Sensitive Amperometric Detection Based on Simple Method of Nickel Nanoparticles Decorated on Magnetite Carbon Nanotubes Modified Glassy Carbon Electrode

A sensitive and selective non-enzymatic glucose sensor was developed based on magnetite (Fe3O4) and nickel nanoparticles decorated carbon nanotubes (Fe3O4-CNTs-NiNPs). Fe3O4 nanoparticles were in situ loaded on the surface of carboxylated multi-walled carbon nanotubes (CNTs-COOH) by a chemical co-precipitation procedure. Nickel nanoparticles (NiNPs) were prepared through reducing nickel chloride by hydrazine hydrate and then decorated on Fe3O4-CNTs using ultra-sonication. The as-prepared Fe3O4-CNTs-NiNPs was characterized using transmission electron microscopy (TEM) and X-Ray Diffraction (XRD). Glucose sensor was fabricated using glassy carbon (GC) coated with Fe3O4-CNTs-NiNPs composites film. Electrochemical investigations indicate that the Fe3O4-CNTs-NiNPs/GC electrode possesses excellent performance in the electrochemical oxidation of glucose at an applied potential of +0.55 V (vs. Ag/AgCl) in 0.1 M NaOH solution. The linear dynamic range for glucose amperometric detection (E-app = +0.55 V) was observed from 10 mu M to 1.8 mM (r(2) = 0.998) with the sensitivity of 335.25 mu A mM(-1); and a low detection limit of 6.7 mu M (S/N = 3). In addition, the fabricated sensor was successfully applied to determine glucose in honey and energy drinks with good results.