Ni-Co alloy nanostructures anchored on mesoporous silica nanoparticles for non-enzymatic glucose sensor applications

Uniform sized Ni-Co alloy nanoparticles were effectively confined over the active channels of mesoporous silica nanoparticles (MSN) using a simple chemical reduction method, and the resultant nanostructures exhibited a spherical configuration with a mean diameter of 5 nm. The face-centered cubic (fcc) crystalline structure of Ni and Ni-Co alloy nanoparticles and the amorphous structure of MSN matrix were identified from the diffraction patterns. The MSN supported catalysts were exploited as electrochemical probes for the detection of glucose, and the controlled morphology, smaller particle size, uniform dispersion and active surface of the Ni-Co alloy nanoparticles improved the excellent electrocatalytic activity of MSN/Ni-Co toward the electrooxidation of glucose. The MSN/Ni-Co nanocomposite exhibited good analytical performance for glucose detection, with a linear response ranging from 0.001 to 5.0 mM, a low detection limit of 0.39 μM and a high sensitivity of 536.62 μA mM^-1 cm^-2. The results of the performed experiments also demonstrated the good reproducibility, long-term stability and high selectivity of the fabricated sensors without the influence of interference from other oxidizable species, which may represent a technically sound and economical new avenue in non-enzymatic glucose sensor applications.