Synthesis and characterization of coralline CuBiS 2 nanocomposite hybridized with reduced graphene oxide: a novel electrocatalyst for ultra-trace detection of insulin in blood serum sample

Addressed herein, Copper Bismuth Sulfide nanocomposite (CuBiS2) in a coralline morphology was synthesized using a hydrothermal procedure. The nanocomposite was studied by X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). A homogenous solution of CuBiS2 and reduced graphene oxide (RGO) led to the formation of CuBiS2/RGO nanohybrid that was applied to modify a glassy carbon electrode. The modified electrode was used for insulin detection in ultra-low levels using differential pulse voltammetry (DPV). The found data represented high electrocatalytic effects for the insulin oxidation process. The fabricated sensor sensitively detected insulin in a linear range of 0.5–59 nM. The limit of detection (LOD) was estimated as 0.047 nM as well appropriate repeatability (RSD = 1.8). Finally, the present sensor was successfully applied for monitoring ultra-trace amounts of insulin with good recoveries in human blood serum samples.