Plasma polymer film structure and DNA probe immobilization

The present work describes the fabrication, characterization, and optimization of NH2-derivatized polymer coatings prepared by pulsed-plasma polymerization for applications as adhesion layers in DNA immobilization. Fourier transform infrared spectroscopy and surface plasmon resonance spectroscopy were used to study (i) polymer matrix properties and (ii) oligonucleotide/DNA binding. The successful DNA attachment on amine functionalized surfaces was found to depend on the macromolecular architecture of the plasma films and on the amine group densities. Pulsed and continuous wave plasma polymers deposited at similar equivalent power showed comparable immobilization properties, while low duty cycle plasma-polymerized films showed a higher sensitivity toward DNA binding than high duty cycle plasma-deposited films. The stabilities of the various films in buffer solution and their reactivities as they were affected by variations in pH have been investigated.