CoFe2O4-Chitosan and Gold Nanoparticles Based Label-free Electrochemical Immunosensor for Determination of Leptin

Herein, a label-free electrochemical leptin immunosensor was demonstrated. The preparation of the sensing platform involved the immobilization of the anti-leptin antibody on the glassy carbon electrode which was modified by cobalt iron oxide (CoFe2O4) nanoparticles, chitosan (CHI), and gold nanoparticles (AuNPs). A simple and rapid determination of leptin was achieved by measuring the change in response before and after the immunocomplex formation using a redox prob solution. SEM examined the surface morphologies of the prepared electrodes. The electrochemical performance of leptin immunosensor was commented via EIS, CV and DPV. Under optimized conditions, a linear response was found between the current peaks acquired from DPV and the logarithm concentration of leptin in the range of 1─4000 ng mL-1 with a detection limit (LOD) of 0.1 ng mL-1. The immunosensor exhibited satisfactory reproducibility.