Self‐Assembled Monolayer (SAM)

Molecular Interactions Driving the Layer-by-Layer Assembly of Multilayers

“…Therefore, and because the purpose of this Review is not to describe the different bottom-up fabrication methods to achieve surface modification and functionalization, the reader is referred to some excellent reviews on this subject. ,,− Nevertheless, a brief description and comparison of the most common bottom-up surface engineering technologies is provided in this Review along with their main advantages and disadvantages. Bottom-up nanofabrication methods include Langmuir–Blodgett (LB) − and self-assembled monolayers (SAMs). − Both methods, which enable the fabrication of closely packed, well-ordered, and organized monolayers and allow for the immobilization of several functional molecules onto surfaces, present some drawbacks that limit their practical applications. , In the case of the LB method, the expensive and specialized instrumentation, the long construction times, and the need for specific and limited molecules, namely, amphiphilic molecules, to prepare the films represent great shortcomings that limit its applicability. Moreover, although this method allows us to prepare multilayer films from oriented monolayers, the absence of a strong molecular interaction between the film and the solid support (no chemisorption is involved during the formation of the LB films) is a problem due to its mechanical instability, which limits the stability and robustness of the films under ambient and physiological conditions and, thus, makes difficult the transfer of the molecules of the film from the air–water interface to the solid support.…”

Hydrolytic and Thermal Stability of Organic Monolayers on Various Inorganic Substrates

“…Organic monolayers have found an impressive variety of applications in the fields of biosensors, micro- and nanoelectronics, chemical and biochemical sensors, nanotribology, lithographic patterning, wettability control, optoelectronics, biomedical appliances, and so on. − For many of these applications, inorganic substrates are used that are often based on silicon, metals, or metal oxides. Here the monolayer provides functionality and acts as an interfacial layer between the substrate and the surrounding environment, which can be either aqueous, e.g., water under physiological conditions, or gaseous, e.g., air at various humidities and temperatures.…”

“…Here the monolayer provides functionality and acts as an interfacial layer between the substrate and the surrounding environment, which can be either aqueous, e.g., water under physiological conditions, or gaseous, e.g., air at various humidities and temperatures. Therefore, the stability of this interfacial monolayer is crucial, as the performance and durability of such devices depends to a large degree on it …”

Rapid Surface Functionalization of Hydrogen-Terminated Silicon by Alkyl Silanols

“…The stability of the monolayer is a crucial parameter, as the performance and durability of biosensing and electronic devices depends on it to a large degree. 65 To study the hydrolytic stability, silanol-derived monolayers were immersed up to 30 days in four different aqueous media containing deionized water, PBS (pH 7.4), an acidic (HCl) solution at pH 3, and a basic (NaOH) solution at pH 11, all under continuous stirring. 66 After 1, 3, 5, 7, and 30 days, samples were cleaned and sonicated in water.…”