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/cm(2). 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 mu g/cm(2). 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.