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

Herein, a label-free electrochemical leptin immunosensor was demonstrated. The sensing platform consists of the immobilizing of the anti-leptin antibody on a glassy carbon electrode (GCE) modified with cobalt iron oxide (CoFe2O4) nanoparticles, chitosan (CHI), and gold nanoparticles (AuNPs). A simple and rapid leptin determination was achieved by measuring the change of current response in a redox probe solution before and after the immunocomplex formation. SEM examined the surface morphologies of the prepared electrodes. The electrochemical performance of the leptin immunosensor was commented on via EIS, CV, and DPV. Under optimized circumstances, 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 subjected immunosensor demonstrated satisfactory reproducibility.