Synthesis of nickel dopped chitosan nanoparticles as a novel platform for electrochemical insulin detection

Nickel modified chitosan nanoparticles are promising catalysts for the determination of bioanalytes such as insulin, glucose, antibiotics, and ascorbic acid. In this study, we synthesized nickel-loaded chitosan nanoparticles to evaluate their potential as surface modifiers for electrochemical sensors for insulin detection. The nanoparticles were prepared using the ionic gelation of chitosan with tripolyphosphate anions, followed by adsorption of nickel ions via ion-exchange resins and surface chelation. The physicochemical properties of the nanoparticles were characterized by scanning electron microscopy with EDX analysis, transmission electron microscopy, Fourier-transform infrared spectroscopy, and dynamic light scattering. The catalytic activity of nickel modified chitosan nanoparticles towards insulin oxidation was investigated through cyclic voltammetry. The resulting screen-printed carbon electrode modified with nickel-chitosan nanoparticles exhibited exceptional analytical performance, including high sensitivity (0.09 mA μM), a low detection limit (0.02 μM), and a wide dynamic range (300 nM–5 μM). Additionally, the modified screen-printed electrode demonstrated excellent selectivity, enabling accurate insulin determination in the presence of interferences and in real blood serum samples. These findings highlight the potential of nickel-modified chitosan nanoparticles as a surface modification strategy to enhance the performance of electrochemical sensors insulin detection and pave the way for their application in various bioanalytes determination platforms.