Design and characterization of surface-enhanced Raman scattering nanoparticles as spectroscopic probes for biological imaging

Surface-enhanced Raman spectroscopy;Gold nanoparticles;Light scattering;Surface modification

Devetter, Brent M.

关键词: Surface-enhanced Raman spectroscopy;    Gold nanoparticles;    Light scattering;    Surface modification;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/90718/DEVETTER-DISSERTATION-2016.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The development of highly sensitive and chemically specific optical probes has only been marginally realized to date. Surface-enhanced Raman spectroscopy (SERS) is an emerging technique that offers both chemical sensitivity and specificity. This dissertation examines the rational design, synthesis, characterization, and application of SERS-based optical probes designed for biological imaging and chemical sensing experiments. Special attention is paid to both the probe stability and the stability of its chemical signature. Our results indicate that significant care is required to successfully manufacture and use probes that are intended for biological investigation. An inner-filter effect between the extinction of light propagating through a matrix of probes, modeled as a colloidal solution, and surface-enhancement requires precise selection of the laser excitation wavelength and the optical properties of the probe. Metallic nanostructures consisting of noble metals such as gold and silver were investigated as probes because they provide intense surface-enhancement effects and the ability to tune their optical properties as desired. In particular, gold nanostructures are highly desirable because of their biocompatibility and inertness. Surface chemistry modification and characterization of metallic nanostructures were investigated to further our understanding of the requirements needed for preparing highly stable probes. Light scattering simulations were performed to predict the influence of certain geometries, materials, and illumination modalities on the probe's optical properties. This dissertation discusses studies that have investigated the long-term stability nanoprobes, the kinetics of surface ligand exchange, nanoprobe imaging in cellular systems, the properties of reflective substrates, and electron microscopy characterization of metallic nanostructures.