Gold-supported hybrid bilayers comprising
phospholipids and alkanethiols
have been found to be highly useful in biomembrane mimicking as well
as biosensing ever since their introduction by Plant in 1993 (Plant,
A. L. <i>Langmuir</i> <b>1993</b>, <i>9</i>, 2764β2767). Generalizing the mechanism (i.e., hydrophobic/hydrophobic
interaction) that primarily drives bilayer formation, we report here
that such a bilayer structure can also be successfully obtained when
aromatic thiols are employed in place of alkanethiols. Four aromatic
thiols were studied here (thiophenol, 2-naphthalene thiol, biphenyl-4-thiol,
and diphenylenevinylene methanethiol), all affording reliable bilayer
formation when 1-palmitoyl-2-oleoyl-<i>sn</i>-glycero-3-phosphocholine
liposomes were incubated with self-assembled monolayers of these thiols.
Characterization of the resultant structures, using cyclic voltammetry,
impedance analysis, and atomic force microscopy, confirms the bilayer
formation. Significant differences in electrochemical blocking and
mechanical characteristics of these new bilayers were identified in
comparison to their alkanethiol counterparts. Taking advantage of
these new features, we present a new scheme for the straightforward
biorecognition of a lipolytic enzyme (phospholipase A<sub>2</sub>)
using these phospholipid/aromatic thiol bilayers