Covalent Organic Monolayers

Upon immersing the substrates in the appropriate (organic) solution, the chemical bonds are formed, if necessary by exposure to heat or light. The layers thus obtained are often referred to as SAMs. Because the preparation of such covalent organic monolayers belongs to the domain of organic chemistry, we only briefly indicate the main principles and features. 

Ranganathan S, Steidel I, Anariba F, McCreery RL (2001) Covalently bonded organic monolayers on a carbon substrate a new paradigm for molecular electronics. Nano Lett 1 491 194... 

In the 1940s, it was demonstrated in the pioneering work of Zisman and coworkers [8] that the LB technique is not the only way to create an organized organic monolayer on a solid substrate. It was demonstrated that when a compatible substrate is exposed to a solution of an amphiphilic compound, the dissolved molecules form a self-assembled monolayer on the substrate surface. Such films maintain their structural integrity after they are removed from solution. The most common examples of such films are organosulfur films on gold substrates [9] and alkyltrichlorosilane films on silicon dioxide substrates [10]. Compared with the LB films, the self-assembled films are somewhat less ordered. On the other hand, these films are easier to prepare, since they do not require special instrumentation and can easily be deposited on both planar and non-planar substrates. Also, in many cases the amphiphilic molecules which make the self-assembled film are chemisorbed on the substrate. Such films are more stable when heated or exposed to solvents than are typical LB films, which are held to the substrate by non-covalent interactions. 

Several useful schemes for attaching nucleic acid probes onto electrode surfaces have thus been developed [2-8]. The exact immobilization protocol often depends on the electrode material used for signal transduction. Common probe immobilization schemes include attachment of biotin-functionalized probes to avidin-coated surfaces [15], self-assembly of organized monolayers of thiol-functionalized probes onto gold transducers [16], carbodiimide covalent binding to an activated surface [17], as well as adsorptive accumulation onto carbon-paste or thick-film carbon electrodes [15-30]. 

Eor heterogeneous electron transfer, the use of ordered organic monolayers (self-assembled monolayers or SAMs) at electrode surfaces as blocking films either with electroactive species in the electrolyte [26] or with electroactive groups tethered at the opposite end of the blocking molecule from the covalent attachment end [27] has provided a method to study the effect of electrode-redox center distance and the effect of the electrode potential on the electron-transfer rate. 

Optoelectronics XPS Passivated luminescent PS based on organic monolayers covalently attached Control of different oiganie moleeules (alkenes and noneonjugated dienes) attachment process to tiie surface fluough Si-C bonds Boukherroub et al. (2001), Lin et al. (2011), Hong etal. (2010), Harraz etal. (2002)... 

Thermal Stability of Organic Monolayers Covalently Grafted on Silicon Surfaces... 

Thermal Stability ol Organic Monolayers Covalently Grafted 21... 

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