Hydrophobic carbon dots: An overview of the synthesis, purification, cytotoxicity, and potential applications in food safety and analytical chemistry

Hydrophobic carbon dots (HCDs) represent a burgeoning class of nanomaterials distinguished by their unique physicochemical, antimicrobial, and optical properties. These attributes have propelled HCDs to the forefront of research, particularly in the fields such as composite film production, biological imaging, and antibacterial coatings, with broad implications for industries, such as food safety, medicine, catalysis, and sensor technology. This comprehensive review delves into the diverse synthesis methodologies of HCDs, such as chemical oxidation, hydrothermal/solvothermal techniques, pyrolysis, and microwave irradiation. The comparative benefits and challenges of these methods were analyzed critically. This manuscript presents an in-depth exploration of purification methods, hydrophobicity indices, and cytotoxicity by a thorough examination of current literature. In addition, it highlights the innovative applications of HCDs, from advanced chemosensors, the development of stationary phases for chromatography to bioimaging and diagnostics, and the construction of optoelectric devices for food applications.