Molecular engineering of a self-assembling nucleobase coating with nano-scale control

There is a major thrust to create biomaterial coatings that are blood compatible. The use of small molecular weight monomers (MW∼1000) that surface assemble into a supramolecular coating has the potential to be tunable on the nano-scale. This type of coating can be used to control the surface density of presented biological groups. This thesis focuses on the molecular engineering of a nucleobase supramolecular coating that assembles from small molecular weight monomers.; The assembly of the monomers on highly oriented pyrolytic graphite (HOPG) is characterized with a perspective of using a surface as an additional ordering effect to aid two dimensional supramolecular polymerization (Chapter 4). We find that the monomers form linear bands that we can characterize by measuring the band width. Molecular modeling is used to help understand how the molecules may be arranged. By tuning the hydrocarbon length, the band spacing can be tuned. Additionally, we provide evidence that the proposed guanine motif is stabilizing small molecules relative to larger molecules.; Through a series of monomer experiments, Chapter 5 explores other molecular components that may influence the band spacing. In particular, the band spacing is investigated with more monomers, and there is no significant change to band spacing when the nucleobase is changed. This chapter also takes a closer look at combined monomer assemblies and suggests that the different arrangements within a combined monomer assembly can change the band spacing.; To gain some understanding of the growth of these assemblies, monofunctional molecules were studied on HOPG. Chapter 6 explores the growth of the assembly and suggests that the weaker alkyl-alkyl interactions assemble at a growth rate that is an order of magnitude slower than hydrogen bond controlled assembly.; We are interested in modifying surface properties to reduce surface thrombosis. Non specific protein adsorption and platelet adhesion are the first steps that lead to surface induced thrombosis. In Chapter 7, we first show that an attached side chain does not significantly change the band spacing. We also demonstrate that supramolecular coatings can reduce static platelet adhesion on both HOPG and octadecyltrichlorosilane (OTS) coated glass cover slips.