Single-walled carbon nanowires-integrated SPR biosensors: A facile approach for direct detection of exosomal PD-L1

Single-walled carbon nanowires (SWCNWs) possess remarkable mechanical and electronic properties under tension, biocompatibility, π-π stacking interactions with biomolecules, and a large surface area. However, the progress in developing SWCNWs for biosensing applications has been sluggish. This study investigates their potential to improve the performance of surface plasmon resonance (SPR) sensing. Furthermore, the large surface area of SWCNWs allows for high surface coverage of multifunctional peptides at the sensing interface. Through the modification of the SPR sensing interface with multifunctional peptides that combine carbon material affinity, programmed cell death 1 ligand 1 (PD-L1) recognition, and antifouling properties, we have accomplished the highly sensitive, real-time, rapid, and specific label-free detection of exosomal PD-L1 (ExoPD-L1). This work provides a promising new direction for SWCNWs in biosensing applications.