Graphene quantum dot-based on-chip electrochemical DNA hybridization sensor for pancreatic cancer

Abstract: A new sensitive sensor based on graphene quantum dots was constructed and used to detect gene mutations in pancreatic cancer (PC). PC is a leading cause of death worldwide and is considered a hard-to-treat malignancy due to its late diagnosis and lowest 5-year survival rate of 2%–7%. Despite significant advances in detection techniques, PC is often diagnosed at advanced stage, with limited treatment options available, which leads to death in the majority of cases. In this regard, it is extremely important to develop methods for early detection of this lethal disease. In this study, we explored the advantages of electrochemical biosensing and designed a simple screen-printed DNA sensor for the detection of gene mutation in PC. p16 is a tumor-suppressor gene, and alterations in the gene sequence are related to PC onset. Therefore, we explored the p16 gene as a cancer marker and designed an electrochemical on-chip sensor system for the early diagnosis of PC. Different electrochemical techniques, such as differential pulse voltammetry and electrochemical impedance spectroscopy, were applied along with other characterization techniques (eg, ultraviolet–visible spectroscopy, scanning and transmission electron microscopy) for designing a simple DNA hybridization sensor for PC. The biosensor showed a detection capability of 0.10 pM. This study establishes the utilization of graphene quantum dots as a sensor matrix and a new approach for detecting gene mutation on a chip, which can be further developed as an integrated portable detection system. Keywords: electrochemical biosensor, DNA hybridization, p16 gene, pancreatic cancer, screen-printed electrodes, cancer biomarkers