Graphene-Based Electrochemical Biosensors

Electrochemical biosensors have emerged as powerful tools for the rapid, sensitive, and specific detection of various analytes in fields like medical diagnostics, environmental monitoring, and food safety. This thesis focuses on graphene-based electrochemical biosensors, leveraging graphene's exceptional electrical, mechanical, and thermal properties to enhance sensor performance. Key biosensing platforms, including amperometric, potentiometric, impedance, and field-effect transistor (FET) designs, are discussed in detail. Graphene is utilized due to its high surface area, excellent electrical conductivity, and strong chemical stability, which significantly enhances the sensitivity and performance of electrochemical biosensors. Special emphasis is placed on functionalization strategies to improve selectivity and sensitivity, enabling precise biomolecular detection such as glucose, dopamine, and viral proteins like SARS-CoV-2 spike protein. Methods for graphene synthesis, including top-down and bottom-up approaches, are also considered. This work highlights the critical role of graphene in advancing biosensor technologies for point-of-care diagnostics and next- generation applications.