Sustainable synthesis of multifunctional carbon dots using biomass and their applications: A mini-review

Recently, carbon dots (CDs) have received increasing attention, and several reports have indicated that CDs are promising fluorescent carbon-based materials. CDs present outstanding physical and chemical properties because of their excellent properties, CDs are used in a wide range of applications, such as bioimaging, sensing, drug delivery, and nanoelectronics. Numerous approaches can be used to prepare CDs, such as arc discharge, laser ablation, electrochemical exfoliation, chemical oxidation, ultrasonic passivation, combustion, microwave pyrolysis, the template method, and the hydrothermal method. In addition, basic techniques used for the separation of CDs are included and discussed shortly. In this short review, the synthesis and characterization of CDs from plant sources using the eco-friendly hydrothermal method is described. Further, the importance of hydrothermally synthesized CDs is discussed briefly. The applications and advantages of CDs in bioimaging, fluorescent inks, and detections or sensing are also reported herein. Finally, we summarize the importance, challenges, and future direction towards the research of CDs.