Characterization of an interaction between functionalized carbon nanotubes and an enzyme.

Carbon nanotubes (CNTs) did not exhibit strong interactions with Biliverdin IX beta reductase enzyme (BVRB) in water. With the use of noncovalent functionalization by the surfactant Triton X-100, the surfaces of the CNTs were changed from hydrophobic to hydrophilic. The hydrophilic surface of the CNT-Triton conjugate interacts with the hydrophilic surface of BVRB, thus creating a water-soluble complex. Results from ultracentrifugation through a sucrose gradient and gel electrophoresis show the presence of the enzyme. Raman spectroscopy confirmed that the enzyme indeed interacts with CNT-Triton conjugates.