Jackson State University
Michael J. Gordon
Faculty Sponsor's Department(s):
LIGHTS, CAMERA, ACTION! MOLECULAR SURFACE IMAGING VIA ENHANCED LIGHT-MATTER INTERACTIONS
Scanning probe microscopy (SPM) is an efficient technique for surface characterization on the nanoscale. By using one form of STM, scanning tunneling microscopy (STM), one is able to surpass the wavelength diffraction limit and clearly image surfaces on the atomic level. Raman spectroscopy is a technique used for the unique detection for molecules’ rotational, vibrational, and other low frequency modes via light scattering. The ultimate goal of this project is to develop a hybrid SPM system that can topographically and chemically image surfaces with nanoscale spatial resolution. The instrument simultaneously applies atomic force microscopy (AFM) and STM with near field optical examination, using electrochemically etched tips to amplify the Raman signal from the surface for SPM. The tips are probed across the fabricated surface, where powerful electromagnetic fields are created, ultimately allocating surface chemical imaging through near-field vibrational [Raman] spectroscopy. For the STM-Raman conjunction, glass slides are coated with gold and have thiol-linkers attached, where STM imaging using Au, W, and Ag tips allow for the surface imaging. The slides are then struck by laser light for molecular excitation, thus allowing detection of the linkers groups, allowing nanoscale detection and imaging via unique chemical signaling. In this work, techniques are currently being developed for higher image resolution and STM tip fabrication processes.