MRI: Track 1 Development of a Dual-Comb Fluorescence-Detected Photothermal Mid-Infrared (DC-FPTIR) Microscope

This award is jointly supported by the Major Research Instrumentation (MRI), the Chemistry Research Instrumentation, and Chemical Measurement and Imaging (CMI) programs. Purdue University is developing a novel fluorescence-detected photothermal microscope using a dual-comb laser source to support the research of Professor Garth Simpson along with colleagues Yoon Yeo, Lynn Tayler, Arezoo Ardekani, and Paul Schmitt. This instrument facilitates research in the areas of nanoparticle and advanced materials analysis, fundamental studies of biological systems, and measurement of molecular composition in plants and animals. The instrument enables high-resolution optical microscopy with contrast arising from specific molecular bonds. In general, dual-comb spectroscopy uses high frequency optical signals to produce radio-frequency beat patterns that can be detected by high-speed digitization. These beat patterns modulate the local temperature and the corresponding fluorescence intensity. Infrared spectroscopy is then performed with a spatial resolution set by fluorescence microscopy and IR-fluorescence colocalization dependent on the local thermal conductivity. In addition to supporting fundamental science directly, this award targets the enhancement of educational, research, and research training at all levels in multiple departments. This developed instrument is also used to benefit activities within the NSF-supported Center for Bioanalytic Metrology, an NSF Research Experience for Undergraduates (REU) program, and major outreach and educational activities of the newly established Young Institute for Advanced Manufacturing of Pharmaceuticals. This award is aimed at enhancing research and education at all levels. Specifically, the development of this instrument offers the unique ability to perform the spectroscopy characterization of therapeutic nanoparticle transformations. The instrumentation enables chemical mapping within phase separated domains affecting dissolution in therapeutic materials. By using the dual-comb laser source, this instrument also aids in the structural elucidation and compositional changes during virus maturation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.