Author: Joshua Stephen OstranderPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Two-dimensional infrared spectroscopy (2D IR) is a nonlinear spectroscopic technique with applications in fields ranging from biophysics to materials science. In this dissertation, I report several new technical advances in 2D IR spectroscopy and provide examples of some applications in biophysics and materials science. The advances presented will lead to wider adoption in both the complexity of scientific questions that 2D IR can address and reduce the barrier for non-experts to enter the field. In the first study, I report the development of pulse shaping based Fourier transform infrared (FTIR) spectroscopic imaging. We show that the microscope can distinguish between chemical species with diffraction limited resolution. Second, I present the design and construction of the first wide-field microscope to spatially resolve 2D IR spectra. The differences in image formation between FTIR and 2D IR images are also presented. Next, I present an application of 2D IR spectroscopy to the study of energy transfer in the secondary explosive pentaerythritol tetranitrate (PETN). The FTIR and time-dependent 2D IR spectra are presented and energy transfer is identified. Additionally, we use transition dipole strength measurements to conclude that the excitations are delocalized over 15-30 nitrate ester groups. I also present methods for measuring the 2D IR spectra of monolayers by capitalizing on the signal enhancement from plasmonic gold films. Additionally, we show that a reflection geometry can further enhance signal strengths. We study the structure of cysteine terminated ovispirin on a gold surface in [D2O] and [H2O]. In the seventh chapter, I present a 2D IR immuno-sensor to measure the structure of proteins extracted from solution. The experiment utilizes surface-enhanced 2D IR spectroscopy to measure a monolayer of sequence specific antibodies chemically linked to a thin film of gold. We also show that that we can resolve single isotope labels on the antibody. Finally, I present the design and construction of a 50 kHz 2D IR spectrometer with a KGW doped Ytterbium amplifier. I present the design of our home-built optical parametric amplifier and evaluate the performance of the system in high repetition rate 2D IR measurements.
