Introduction
Organothiols on noble metals such as gold
have been developed as a model system
of self-assembled monolayers (SAMs).
These organic thin ? lms offer a spectrum
of promising applications, including
lubricating layers, corrosion inhibitors,
lithographic resists, and chemical or
biological sensors.
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After the immersion of a gold substrate
into an alkanethiol solution, thiols will
spontaneously bind to the surface with
the SH headgroups via a strong gold-sulfur
interaction and typically adopt a standing-
up con? guration in the resulting closely
packed monolayer, thus exposing the
endgroups at the layer/medium interface.
Tailoring the terminated chemical identity
of self-organized assemblies renders an
effective means to functionalize gold and
tune the surface physical or chemical
properties to meet speci? c requirements.
In fact, rich endgroup chemistry is one
of the primary advantages of SAMs
and therefore de? nes many surface
engineering applications. For example,
SAMs capped with a polar hydroxyl or
carboxylic acid functionality result in
hydrophilic surfaces, whereas methyl-
terminated layers are hydrophobic.