Nickel nanoparticle-modified electrode for ultra-sensitive electrochemical detection of insulin

An ultra-sensitive electrochemical sensor for the detection of insulin was fabricated, using low-cost and environmentally friendly nickel nanoparticles (NiNPs) by ion implantation. The morphology and structure of the NiNPs are characterized by scanning electron microscopy (SEM), revealing diameters ranging from 4 to 8nm. The insulin assay performances were evaluated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (I–t). The NiNPs-modified indium tin oxide electrode (NiNPs/ITO) showed excellent analytical features, including ultra-high sensitivity (2140μAμM−1) for detecting low concentrations of insulin, an incredibly low detection limit (10pM) and a wide dynamic range (100pM to 2400pM and 1nM to 125nM). In addition, the NiNPs/ITO electrode was also used to analyze the insulin concentration in bovine insulin injections. The NiNPs/ITO electrode is expected to be used as a potential biosensor for insulin. •Ion implantation is an eco-friendly and easy-to-use technique.•NiNPs/ITO electrode shows well electrocatalytic properties of insulin oxidation.•The linear relationship was observed in the wide insulin concentration.•NiNPs/ITO electrode exhibited ultra-high sensitivity and much low detection limit.