LASER SPECTROSCOPY OF BIOLOGICAL MACROMOLECULES. I. DYNAMIC LIGHT SCATTERING OF POLY-L-GLUTAMIC ACID. II. OPTOACOUSTIC SPECTROSCOPY OF AQUEOUS HEMOGLOBIN

Two areas of laser spectroscopy, dynamic light scattering and optoacoustic spectroscopy, have been investigated. Dynamic light scattering was used to investigate the pH-induced (alpha)-helix-random coil transition in poly-L-glutamic acid. By measuring the translational-diffusion coefficient the transition was monitored as a function of pH. A theoretical investigation was made of the possibility of using DLS to determine the kinetics of the transition. It was determined that this is not possible.; Optoacoustic Spectroscopy was used as an analytical technique to detect human hemoglobin in aqueous solution in nonomolar concentrations. A pulsed laser system was used to excite the solute, and a piezoelectric transducer was used to detect the acoustic waves.