The Chemical Measurement and Imaging program of the Division of Chemistry is supporting Dr. Nathan Lindquist and his undergraduate researchers at Bethel University to develop new methods for high-resolution imaging and spectroscopy using metallic nano-surfaces. Diffraction-limited light microscopy cannot achieve the control of optical fields necessary for many demanding applications in nano-scale imaging, sensing, and spectroscopy. To address this issue, the field of plasmonics aims to manipulate light within dimensions much smaller than the optical wavelength called "hotspots" by exploiting plasmons in metallic nanostructures. The hotspots are then able to provide chemical information via plasmon-enhanced spectroscopy. Using these properties, Dr. Lindquist and his students are developing sub-diffraction-limited chemical imaging substrates. To address challenges associated with the precise positioning of focused hotspots for scanning and imaging purposes, Dr. Lindquist's team is using a spatial light modulator and computer-controlled holographic laser illumination.
The resolution of conventional microscopic methods is on the order of 200 nm, which is too large to observe many cellular components and the structural details of many materials. This project uses a very different strategy to generate microscope images: very small metal structures that can restrict the light collected to very small dimensions and improve image quality. The precise nano-fabrication and nano-characterization techniques explored in this research also will have broad scientific impact because nano-scale metals have many unique properties that macro-scale metals do not. Beyond this, the research is being performed at a primarily undergraduate institution, training motivated students for future careers in science and engineering. The student's work will incorporate cross-disciplinary research activities into their undergraduate education, give them experience with state-of-the-art equipment and experimental techniques, and inspire course projects, research activities, and summer research opportunities.
