Selective adsorption of bilirubin against albumin to oxidized single-wall carbon nanohorns

Bilirubin adsorption capacities of single-wall carbon nanohorns (SWNHs) are investigated to develop an efficient adsorbent in plasma apheresis. Pristine, thermally oxidized and H2O2-oxidized SWNHs are examined and it is demonstrated that higher oxidization levels of the SWNHs enhance bilirubin adsorption capacity owing to increase in their dispersibility and formation of nanoscaled holes on the SWNH walls. Under co-existance of albumin molecules, the bilirubin adsorption capacity of the SWNHs increases with the oxidation level whereas the albumin adsorption capacity is kept small. Bilirubin is selectively adsorbed to the SWNHs, especially to the SWNHs with high oxidation levels, against albumin. This selectivity is maintained under high-concentrations of albumin in the near-clinical environment.