Recent advances in carbon-based quantum dots for sensing applications

Carbon-based quantum dots (CQDs) are an emerging class of nanomaterials with unique features due to their quantum confinement effects. They have attracted tremendous attention due to several special features such as intrinsically low toxicity, high solubility in a variety of solvents, excellent biocompatibility, high specific surface area, abundant edge sites, and their capacity for easy modification with other nanomaterials. Due to these unique attributes, CQDs have been explored for numerous applications, including solar cells, energy storage, catalysis, drug and gene delivery, optoelectronics, sensors, and more. The quest for more sensitive electrodes consisting of cost-effective materials has led to the development of electrochemical sensors using CQDs for the detection of various analytes. In this review, the synthesis and characterization of CQDs are summarized and compared. The sensing applications of CQDs, encompassing biomarker detection, environmental monitoring, food safety and quality control, and the determination of pharmaceutical compounds are highlighted. Further, the challenges and future outlooks in CQDs research are briefly outlined.