Electrochemical Biosensor for Homocysteine Detection Using Poly‐L‐Lysine Coated Reduced Graphene Oxide Nanocomposite

ABSTRACT Homocysteine (Hcy) plays a critical role in cellular metabolism. Elevated levels of Hcy are associated with various pathophysiological conditions such as atherosclerosis, myocardial infarction, thrombosis, and neurodegenerative disorders. In this research, a highly sensitive and selective biosensor was developed for Hcy detection using reduced graphene oxide (rGO), thionine (Thi), gold nanoparticle (AuNP), and poly‐L‐lysine (PLL) electrodeposited on indium tin oxide (ITO) electrode. The prepared sensor was highly sensitive with a limit of detection 3.3 µM and a linear detection range from 10 to 60 µM. The sensor was highly specific and selective for Hcy in the presence of interferents and in human serum samples. The sensor was found to be reproducible with multiple electrodes and showed stability for a week. Developed nanofabricated rGO/AuNP/Thi/ITO platform can be further explored for detection of various clinical biomarkers.