Highly efficient exosome capture by carbon nanowalls template

 Carbon nanowalls (CNWs) are wall-like nanostructured materials consisting of multi-layered graphene sheets vertically standing on substrates. The CNWs have unique properties such as large surface area and high electrical conductivity and are expected to be applied in biology.

 In this study, highly efficient capture of exosomes, one of the extracellular vesicles, was performed employing the CNWs template. the zeta potential of CNWs was also measured to discuss electrostatic interactions between the CNWs and exosomes.

 The zeta potential of CNWs was -23 mV, and that of exosomes is known to be negative. Therefore, it can be inferred that the exosome capture efficiency on the CNWs was reduced due to Coulomb repulsion. However, the actual capture efficiency of exosomes on the CNWs was over 90 %, which is higher than those in the previous studies. The maze-like structure of CNWs may have affected the capture efficiency of exosomes. In other words, the capture efficiency of exosomes on the CNWs can be further improved by shifting the zeta potential of CNWs positively by the plasma surface modification.