Adsorption of DNA on Organic Semiconductor Films and its characteristics

It is known that DNA is a well-characterized intracellular target but its size and sequential characteristics make it an elusive target for selective drug action. Binding of low molecular weight ligands to DNA causes a variety of significant biological responses and is one of the most compelling issues in bio-nanotechnology research. Transistors are sensitive devices where the characteristics of the device reveal information about the intrinsic properties of the active materials involved, mainly the semiconductor material. Among -conjugated semiconductors, one of the most studied systems, both for the fundamental properties and for the electronic applications is -sexithiophene (T6). T6 ultra-thin films were grown by sublimation in ultra-high vacuum (base pressure 10 Pa) with a rate of 0.02 Å s on thermal silicon dioxide held at 120 °C. These deposition conditions give the highest field-effect charge mobility for T6 films. Afterwards DNA from TRIS buffer solution was deposited on organic film, solution was washed with UHQ water and dried with N gas. Surprisingly, DNA binds strongly organic film just by simple deposition, without any intermediate bridge. Electrical properties of such organic FET were study.-8-12 The stretched contact line of dry linear DNA molecules on T6 may change the response of the transducer by tens of ppm per DNA molecule. The knowledge on the behavior of biomolecules on different surfaces and other technologically relevant systems has crucial importance to pave the way to the new hybrid technological platform.