Ionic liquid/reduced graphene oxide/nickel-palladium nanoparticle hybrid synthesized for non-enzymatic electrochemical glucose sensing

Ionic liquids (ILs) were synthesized for the purpose of graphene oxide modification through π-π bonding and anchoring highly dispersed bimetallic Ni-Pd nanoparticles on reduced graphene oxide (RGO). Metallic ions (Pd2+ and Ni2+) were initially attached to an ionic liquid and graphene oxide composite. The ionic liquid served as a stabilizer following metal ions and graphene oxide sheets reduction by NaBH4, which produced an IL/RGO/Ni-Pd hybrid. The π-π interaction between the synthesized ionic liquid and graphene oxide was characterized by nuclear magnetic resonance spectroscopy (1H NMR), Fourier transform infrared spectroscopy (FTIR), and ultraviolet–visible spectroscopy (UV–vis). The result of transmission electron microscopy (TEM) demonstrated Ni-Pd NPs (3–5 nm in size) were uniformly dispersed on the IL/RGO composite. Electrochemical measurements revealed IL/RGO/Ni-Pd modified glassy carbon electrodes directly catalyzed glucose oxidation and displayed enhanced current response compared with RGO/Ni-Pd including a response time within 3 s, a linear range from 0.2 μM to 10 mM, good reproducibility, considerable stability, and excellent anti-interference to electro-active molecules. The superior catalytic activity and selectivity make the IL/RGO/Ni-Pd hybrid a promising nanomaterial for applications in direct detection of glucose.