Carbon Nanoonion as an Emerging Material; Synthesis, Characterization, and Chemical Sensing Applications

Carbon nanoonions (CNOs) or multi-shell fullerenes are special types of CNMs organized by concentric shells of carbon atoms. Because of their unique chemical and physical characteristics, these cage-within-cage assemblies remain among the most interesting carbon forms, alongside graphene and its derivatives. The high safety and compatibility of CNOs make them an appealing alternative in a variety of applications, including drug design and delivery, tissue engineering, bioimaging, and chemical analysis. This nanomaterial is low in toxicity, disperses well in aqueous solutions (after surface functionalization), and has a high medicinal efficiency. Various techniques have been discovered for CNOs’ synthesis and manipulation. The easy modification of CNOs is one of its attractive properties, which allows for surface modification with numerous functional groups. This chapter discusses the physicochemical properties of CNOs, the different synthesis strategies, the characterization techniques, and the various applications in chemical sensing.