A novel assay for detection platform based on plasma treated CNT through electrical property

The effect of oxygen-containing defects on the adsorption onto plasma-treated single- walled carbon nanotubes (SWCNTs) of two peptide sequences known to bind to the CNT surface was investigated using chemiresistor-type SWCNT devices. A peptide with highly selective affinity for SWCNTs was designed and its mutated peptide was used as a control to compare the adsorption effect on the SWCNTs. The oxygen plasma-treated SWCNT films exhibited rapid increases in electrical resistance when exposed to peptides with high affinity. This peptide sequence with more polar was found to be more sensitive to the oxygen-containing defects on the SWCNTs through polar covalent bonds. These results indicate that peptide absorption affects the electron-withdrawing power of the oxygen-containing defects, thus leading to a reduced carrier concentration in the SWCNTs and the increase in electrical resistance.