Physicochemical lithography of functional nanolayers

Abstract

To further understand the biological interactions that govern our daily lives it is essential to develop new techniques for the robust tethering of immobilized bio-molecules to substrates for applications such as bio-mimicry, diagnostics, and durability as well as further self assembly. Current technologies devised for this purpose include the functionalization and lithography of Langmuir-Blodgett films, self-assembled monolayers and spin-coated layers. Whilst these methods provide suitable surfaces, they suffer from being substrate dependent and inappropriate for complex 3D-geometries, thus prohibiting their application to a wide range of materials. Pulsed plasma polymerised films can overcome this hurdle and are utilised in this thesis to present amine, epoxide, thiol and protein resistant Interfaces. For instance, genomic an-ays have been created via di-sulfide bridge formation between DNA and thiol groups. Whilst proteomic arrays have been fabricated either via electrostatic immobilization of proteins to charged regions surrounded by a protein resistant background, or alternately, covalent attachment to epoxide surface groups. Similarly, glycomic arrays have been produced by the covalent attachment of D-maltose and p-D-galacto-methanethiosulfonate to amine and thiol surface groups respectively. Furthermore, it has been shown that sequential plasmachemical nanolayering can provide a passivated upper layer and a reactive underlayer which can be subsequently exposed via mechanical removal of the top layer, to yield reactive pixels on the micron and nano-scale. Finally, the substrate independent nature of plasma polymers has been utilised for the coating of compact disc surfaces with reactive nanolayers. Subsequent protein immobilization has been accomplished via Inkjet printing and has shown promise for potential use as in point-of-care diagnostics.