An electrochemical biosensor for the determination of hormone Human Chorionic Gonadotropin (hCG) in human serum

This work describes the modification of a gold electrode to create an electrochemical biosensor capable of detecting human chorionic gonadotropin (hCG). The biosensor was obtained by modifying the gold electrode with cysteamine and oligopeptide (PPLRINRHILTR). The modification steps of the gold electrode were confirmed by cyclic voltammetry (CV) and impedance electrochemical spectroscopy (EIS) measurements. The conducted EIS experiments in 0.01 M PBS, pH 7.4 confirm that the biosensor exhibits sensitivity towards hCG in a range of concentrations from 1×10⁻¹² to 1×10⁻⁷ M (0.5 mIU/mL – 50 000 mIU/mL) to solutions with a detection limit of 1. 91×10⁻¹⁴ M (0.0095 mIU/mL). The effectiveness of the investigated biosensor was also investigated in human serum. The EIS comparative investigations were performed in human serum containing a concentration of 1×10⁻¹² M (0.5 mIU/mL) hCG and in human serum where the hCG was added. The obtained results indicate that the investigated biosensor is selective for the presence of hCG hormone in the human serum.