In this paper the functionalization of single walled carbon nanotubes (SWNTs) with the site-specific single aminoacid mutant D96N of Bacteriorhodopsin (PM- D96N) in its native purple membrane (PM) patches has been investigated in view of the possible application of such nanocomposites as active materials in FET or impedance sensors. The procedure of functionalization has been performed without using any chemical, including surfactants which can delipidate the PM. Absorption spectroscopy investigations provide evidence of the occurrence of hydrophobic interactions between the SWNT walls and the PM - D96N. The PM - D96N biosystem seems to undergoes conformation changes due to assembling on the nanotube walls. The chemical interactions among the components can effectively combine the sensitivity of PM-D96N with the ballistic charge transport properties of the SWNTs to exploit in electronic …