Self-assembled thiol monolayers

Luderer F, Walschus U (2005) Immobilization of Oligonucleotides for Biochemical Sensing by Self-Assembled Monolayers Thiol-Organic Bonding on Gold and Silanization on Silica Surfaces. 260 37-56... 

Sheen C W, Martensson J, Shi J, Parikh A N and Allara D L A 1992 New class of organized self-assembled monolayers—alkane thiols on GaAs(IOO) J. Am. Chem. Soc. 114 1514-5... 

Ruths, M., Boundary Eriction of Aromatic Self-Assembled Monolayers Comparison of Systems with One or Both Sliding Surfaces Covered with a Thiol Monolayer," Langmuir, Vol. 19,2003,pp.67-88. 

Self-assembled monolayers (SAMs) [8] The layers are formed by heterologous interaction between reactive groups, such as thiols, and noble metals, such as gold or silver. Since the molecules are selectively adsorbed on these metals, film growth stops after the first monolayer is completed. The molecular aggregation is enthalpy driven, and the final structure is in thermodynamic equilibrium. 

This bulky ligand has two thiols to produce small Au nanoparticles. Figure 5 presents the TEM images of self-assembled monolayers of 1.5nm TCgBIP- and 1.6nm TCsBIP-protected Au nanoparticles at the air-water interface. 

For transition and precious metals, thiols have been successfully employed as the stabilizing reagent (capping reagent) of metal nanoparticles [6]. In such cases, various functionalities can be added to the particles and the obtained nanoparticles may be very unique. It is well known that thiols provide good self-assembled monolayers (SAM) on various metal surfaces. When this SAM technique is applied to the nanoparticle preparation, nanoparticles can be covered constantly by functionalized moieties, which are connected to the terminal of thiol compounds. 

Abraham Ulman, Self-Assembled Monolayers of Thiols, Volume 24, 1998. 

Interest in the adsorption of sulfur-containing molecules at metal surfaces been stimulated by a desire to elucidate the decomposition mechanisms of thiols during the catalytic removal of sulfur from feedstocks and the position of thiols as the favoured head groups for adsorbates used to construct self-assembled monolayers. We shall not survey the extensive self-assembled film literature but restrict our discussion to the simpler thiols. 

Self-assembled monolayers of amphiphilic molecules have been deposited at surfaces since Langmuir and Blodgett developed their dip coating deposition method in 1937.4 These were briefly discussed in Chapter 10 in relation to thiol... 

Coupling of affinity molecules to surfaces also can be enhanced by the use of discrete PEG linkers. Nishimura et al. (2005) modified an amino surface with a NHS-PEG -maleimide crosslinker to create a hydrophilic self-assembled monolayer (SAM) surface that was thiol reactive for the conjugation of sulfhydryl-modified RNAs. This array then was used to investigate the binding specificity of synthetic kanamycins with selected RNA sequences to prove the specific interaction of ribosomal RNA with this molecule. The PEG linkers on surfaces provide lower nonspecific binding character than alkyl linkers, when preparing SAM surfaces for affinity interactions. 

F. Frederix, K. Bonroy, W. Laureyn, G. Reekmans, A. Campitelli, W. Dehaen, and G. Maes, Enhanced performance of an affinity biosensor interface based on mixed self-assembled monolayers of thiols on gold. Langmuir 19, 4351-4357 (2003). 

Kittredge KW, Fox MA, Whitesell JK (2001) Effect of alkyl chain length on the fluorescence of 9-alkylfluorenyl thiols as self-assembled monolayers on gold. J Phys Chem B 105 10594-10599... 

Hou et al. developed a method that controlled the generation of a nanomolar amount of NO [173]. A self-assembled monolayer of N-nitroso-N-oxy-p-thiomethyl-benzeamine ammonium salt bound to a gold electrode via a thiol linkage was used for the reaction. When an electric potential was applied, one-electron electrochemical oxidation led to the release of NO (Scheme 3.20). There was a linear relationship between the amount of NO generated and the area of the electrode, indicating that the amount of NO release could be controlled by selecting an appropriately sized... 

---