Self-assembled monolayers terminal groups

Self-assembled monolayers terminated with COOH and H2PO4 groups, form bone-like apatite on their surfaces in an SBF [34]. This means that COOH and H2PO4 groups are also effective for apatite nucleation. These functional... 

Tegoulia and Cooper studied S. aureus adhesion on self-assembled monolayers terminated with methyl, hydroxyl, carboxylic acid, and tri(ethylene oxide) groups. Results showed how bacterial adhesion was lower on the hydrophilic ethylene oxide-bearing and hydroxyl-bearing surfaces. However, preincubation of surfaces with fibrinogen increased microbial adhesion on all surfaces and minimized the effect of the surface properties of the substrate. The authors concluded that even if surfaces rich in ethylene oxide groups can be used to prevent bacterial adhesion under physiological conditions, most of the substrate properties are masked and their effect on adhesion becomes minimal. 

Faucheux N, Schweiss R, Liitzow K, Werner C, Groth T (2004) Self-assembled monolayers with different terminating groups as model substrates for cell adhesion studies. Biomaterials... 

Figure 8. Immobilization of antibodies via self-assembled monolayers of alkylthiols terminated with functional group (left) and self-assembled monolayers of alkylthiols terminated with biotin and subsequent capture of streptavidin (right).

The first report of surface-immobilized dendrimers was in 1994 [54]. Subsequently, our research group showed that the amine-terminated PAMAM and PPl dendrimers could be attached to an activated mercaptoimdecanoic acid (MUA) self-assembled monolayer (SAM) via covalent amide linkages [55, 56]. Others developed alternative surface immobilization strategies involving metal com-plexation [10] and electrostatic binding [57]. These surface-confined dendrimer monolayers and multilayers have found use as chemical sensors, stationary phases in chromatography, and catalytic interfaces [41,56,58,59]. Additional applications for surface-confined dendrimers are inevitable, and are dependent only on the synthesis of new materials and the development of clever, new immobilization strategies. 

Zhu Z, Daniel TA, Maitani M, Cabarcos OM, Allara DL, Winograd N (2006) Controlling gold atom penetration through alkanethiolate self-assembled monolayers on Au 111 by adjusting terminal group intermolecular interactions. J Am Chem Soc 128 13710-13719... 

A process similar to that described earlier for TiOi was used to deposit Z1O2 films [61]. Self-assembled monolayers with terminal sulphonate or methyl groups on Si were nsed as snbstrates no film growth occurred on bare Si. The deposition solution was Zr(S04)2 dissolved in an aqueous HCl solution at 70°C. 

For example, chemical contrast images were obtained by lateral force microscopy (LFM) from a topologically flat surface of a self assembled monolayer consisting of chemically different domains. In order to make the chemical adhesion the dominant contribution to the friction signal, the tip was modified by a monolayer with appropriate terminal groups [149-155]. However, since LFM operates in contact mode, the surface deformation is inevitable. 

Self-assembled monolayers (SAMs) provide a versatile system for control of the interfacial properties of inorganic compounds. SAMs result from the spontaneous adsorption and assembly of molecular compounds into crystalline structures. Commonly used molecules consist of a head group with a specific affinity for a particular material, and a terminal group containing a chemical function that becomes exposed... 

Fig. 1 An ideal self-assembled monolayer of alkanethiolates supported on a gold surface. The terminal groups are amenable to synthesis, providing a means to immobilize and present ligands from the surface the alkyl chain spacer promotes tight, regular packing, and the gold-sulfur interface stabilizes surface atoms and alkane chains during packing...

Kubiak and coworkers used STM in an ultra-high vacuum environment to study the conductance through self-assembled monolayers of simple Jt-conju-gated, thiol-terminated molecules on gold [21-23, 59] Early work, which focused on the p-xylyldithiol 82 monolayers [22, 23], was later expanded to include also short oligophenylenes (OPs) (81 and 83) that were terminated at either one or both ends by thiol or isocyanide groups [21]. Based on this work, a relatively simple model was presented to account for the observed conductance spectra of the junctions [22],... 

Valiokas, R., Svedhem, S., Svensson, S.C.T., andLiedberg, B. 1999. Self-assembled monolayers of oligofethylene glycol)-terminated and amide group containing alkanethiolates on gold. Langmuir, 15 3390. ... 

Organothiols chemisorbed on gold surfaces are especially usefiil for electrochemical and chemical studies. For example, carboxylic acid terminated monolayers are often used. An example is the attachment of cytochrome C with its side chain lysine groups to acid terminated self assembled monolayer gold electrodes. Carbodiimide mediated esterification of ferrocene-l,l -dicarboxylic acid with phenols is used to construct thermotropic liquid crystals. ... 

---