Surface-enhanced Raman spectroscopy (SERS) is a surface technique in which molecules near nano-rough metallic surfaces can be detected with high sensitivity and high specificity. In the Moskovits lab, a SERS substrate has been developed that is fabricated entirely using foundry techniques and has been shown to be both highly enhancing and highly uniform. These substrates can be used to approximate a flat surface and thus are useful for studying two-dimensional systems.
Fabricating biomimetic cell membranes is of great interest as a model system to study signal transport across the cell membrane. We are interested in forming biomimetic system on our SERS substrate to spectroscopically characterize conformational changes in membranes during dynamic processes across membranes.
Our approach to forming model systems for these studies involves forming hybrid bilayer systems previously synthesized in the literature. First, a self-assembled monolayer of alkanethiol is formed on the SERS substrate gold surfaces. Then, a complementary layer of a phospholipid is formed to create a bilayer system into which small molecules and proteins involved in signal transport can be incorporated. Topographical studies will be done of both the alkanethiol monolayer and the hybrid bilayer using atomic force microscopy (AFM) and ellipsometry in addition to the spectroscopic studies done by SERS. After completion of these hybrid bilayers, we will be able to obtain sensitive and accurate information on a wide variety of dynamic processes across the cell membrane. This information can be used to create biomimetic systems that would be useful for several biomedical applications.