Characterization and application of hydrophobin-dispersed multi-walled carbon nanotubes Original Research Article

Hydrophobins are amphiphilic proteins with high surface activity, which can readily adsorb on interfacial surfaces, especially on hydrophobic surfaces. Based on their properties, we used the class I hydrophobin isolated from Grifola frondosa (HGFI) to disperse multi-walled carbon nanotubes (MWCNTs) in water. MWCNTs could be effectively dispersed by 30-min sonication in a 0.1 mg/ml HGFI solution. Optical absorption and transmission electron microscopy provide evidence for individually stable dispersed MWCNTs. X-ray photoelectron, Fourier transform infrared, and Raman spectroscopies and thermogravimetric analysis suggest that HGFI can non-covalently bind to MWCNTs through hydrophobic interaction, rendering them hydrophilic. A quartz crystal microbalance and immunological sandwich assay were used to demonstrate that the HGFI-coated MWCNTs can be used to immobilize human immunoglobulin G in solution.