Graphene and graphene-derivative electrochemical biosensors for CRC biomarkers

Colorectal cancer (CRC) is known as one of the most common types of cancer in the world, and its early detection plays a decisive role in the success of treatment and preventing the spread of tumors in the body. Early detection is usually done through the identification of biomarkers, and the use of new sensing technologies can significantly improve the detection process. In recent years, the development and application of various biosensors, including electrical, optical, mechanical, and electrochemical sensors, for CRC detection has attracted considerable attention from researchers. Among them, electrochemical biosensors are considered a very suitable option for CRC detection due to their features such as short detection time, high sensitivity, and the ability to detect very small amounts of biomarkers. In general, combining these sensors with various nanostructures can significantly increase their sensitivity and stability. Among these nanomaterials, graphene and its derivatives, including graphene oxide (GO), reduced graphene oxide (rGO), and graphene quantum dots (GQDs), have attracted significant attention due to their unique electrical properties, high specific surface area, excellent conductivity, and superior mechanical properties, making them ideal candidates for the fabrication of electrochemical biosensors. This review focuses on graphene-based electrochemical biosensors for CRC detection over the past five years, analyzing key biomarkers such as carcinoembryonic antigen (CEA), carbohydrate antigen 19–9 (CA 19–9), and microRNAs (miRNAs), which are commonly used for CRC diagnosis. In addition, indicators such as the linear performance range (LR), typically ranging from nanomolar (nM) to micromolar (μM), and the limit of detection (LOD), ranging from femtomolar (fM) to nanomolar (nM) concentrations, have been discussed. Finally, alongside outlining the challenges associated with the development of this category of biosensors, future prospects and strategies aimed at enhancing efficiency, selectivity, reproducibility, and broadening the clinical applications of graphene-based electrochemical biosensors have also been discussed. Overall, this study demonstrates that combining graphene with advanced sensing technologies could pave the way for the development of rapid, accurate, and reliable diagnostic tools, contributing to significant progress in the early detection of CRC. • Overview of current biosensor technologies applied for colorectal cancer detection. • Focus on recent advances in graphene-based electrochemical biosensors. • Graphene nanostructures enhance sensitivity, conductivity, and biomarker detection. • Comparison of graphene-derived materials for CRC-related biomarker sensing. • Identification of challenges, limitations, and future directions for clinical translation.