The properties, microscopic organization and behavior as the cellular matrix of an all-conjugated
polythiophene backbone (PTh) and well-de
fi
ned poly(ethylene glycol) (PEG) grafted chains have been
investigated using di
ff
erent experimental techniques and molecular dynamic simulations. UV-vis
spectroscopy has been used to determine the optical band gap, which has been found to vary between
2.25 and 2.9 eV depending on the length of the PEG chains and the chemical nature of the dopant
anion, and to detect polaron
/
bipolaron transitions between band gap states. The two graft
copolymers have been found to be excellent cellular matrices, their behavior being remarkably
better than that found for other biocompatible polythiophene derivatives [
e.g.
poly(3,4-
ethylenedioxythiophene)]. This is fully consistent with the hydrophilicity of the copolymers, which
increases with the molecular weight of the PEG chains, and the molecular organization predicted by
atomistic molecular dynamics simulations. Graft copolymers tethered to the surface tend to form
biphasic structures in solvated environments (
i.e.
extended PTh and PEG fragments are perpendicular
and parallel to the surface, respectively) while they collapse onto the surface in desolvated
environments. Furthermore, the electrochemical activity and the maximum of current density are
remarkably higher for samples coated with cells than for uncoated samples, suggesting multiple
biotechnological applications in which the transmission with cells is carried out at the electrochemical leve
