High-performance electric and optical biosensors based on single-walled carbon nanotubes

As a quasi-one dimensional nanomaterial, carbon nanotubes (CNTs) are multifunctional nanomaterials with outstanding electronic, optical, and chemical properties due to large specific surface area, ultrahigh length/diameter ratio, and easy chemical functionalization, which make them promising candidates for high-performance biosensors. Among different type of biosensors, since the main sensing mechanism is to detect the change in the electric or optical properties of CNTs toward the target bio-molecules, single-walled CNTs (SWCNTs) with all atoms on the surface are expected to have greater potential than multi-walled CNTs to fabricate highly sensitive sensing devices. Especially, the chiral-related electronic and optical properties enable SWCNT-based biosensors have more selectivity and realizability by choosing specific semiconducting SWCNTs. With the development of selective synthesis technology of semiconducting SWCNTs, it is believed that semiconducting SWCNTs, preferably monochiral nanotubes, will be widely used to explore next-generation high-performance biosensors. Herein, we comprehensively summarize the latest advances in the SWCNT-based field effect transistor (FET) and optical biosensors. The basic structure and physical properties of SWCNTs are firstly introduced, and then the recent development of SWCNT-FET biosensors and optical biosensors has been systematically summarized, respectively. Finally, we also discuss the current challenges about the SWCNT synthesis and bio-sensing devices, and further perspectives will also be provided for this fast‐developing field.