Fabrication and characterization for the nanoconjugates of pyridyldithio-functionalized multiwalled carbon nanotubes and cytochrome c in Langmuir-Blodgett films.

Monolayers and Langmuir-Blodgett (LB) films of pyridyldithio-functionalized multiwalled carbon nanotubes (pythio-MWNTs) conjugated with cytochrome c were investigated. Quartz crystal microbalance measurements revealed that monolayers of pythio-MWNTs could be deposited on the substrate surface with a surface density of about 270 ng/cm2. The as-prepared LB films of pythio-MWNTs could act as a support to immobilize cytochrome c with the surface density of about 5.2 microg/cm2. Composition, structure and morphology of the films were characterized by using absorption and X-ray photoelectron spectra as well as atomic force microscope. A reversible redox process for the immobilized cytochrome c was revealed with the cathodic and anionic potentials at about -0.55 and -0.3 V versus Ag/AgCl, respectively.