Publication
Biosensors are increasingly utilized across various fields, including medical applications, food safety, and environmental monitoring. They are particularly important in the following application scenarios including real-time monitoring, long-term monitoring, and in vivo sensing. Single-walled carbon nanotubes (SWCNTs) offer notable advantages in optical sensing due to their stable fluorescence yield and the ability to emit near-infrared (NIR) fluorescence with high penetration. To ensure a reliable response to target analytes, SWCNTS need to be well suspended. However, issues related to the stability and efficacy of their suspension systems have posed significant challenges to sensor development. By employing surface modification techniques such as protein loading and polymer encapsulation, researchers can create more stable and effective biosensors, making this an area of significant research interest. Preliminary studies on modifying SWCNT surfaces with proteins and polymers often lacked precise control due to the reliance on the specific properties of the materials used. This thesis comprehensively explores efficient and controllable surface modifications of SWCNTs through rational design. We first demonstrated that protein modification and de novo protein design can achieve a controllable assembly process onto SWCNTs. This chapter proved that the non-covalent binding of proteins onto the surface of SWCNTs can be precision designed and controlled. Following the non-covalent strategy, we describe a method using sp3-defected SWCNTs to covalently attach glucose oxidase (GOx) for biosensor construction. This covalent approach significantly enhances the stability and responsiveness of the protein-SWCNT complex. After optimizing the construction of the protein-SWCNT complexes, we investigated the encapsulation of SWCNTs within hydrogels. In the chapter on the non-covalent hydrogel section, we compared various hydrogels derived from natural sources to evaluate their encapsulation and sensing capabilities, offering valuable insights for future applications. In the covalent hydrogel chapter, hyaluronic acid was employed to form a hydrogel directly linked to the SWCNT backbone, resulting in improved stability and biocompatibility performance. In summary, this thesis is focused on the surface modification of SWCNTs, utilizing both covalent and non-covalent strategies to demonstrate controllable protein loading and hydrogel encapsulation. It expands the toolbox for developing SWCNT-based biosensors and inspires the creation of more practical sensors in the future.