Characterization of Hydrogel and Protein Nanoparticles with Single-Nanoparticle Surface Plasmon Resonance Imaging

The work presented in this dissertation describes the application of near-infrared surface plasmon resonance imaging (SPRI) microscopy to detect and characterize the adsorption of single polymer, hydrogel, and protein nanoparticles onto chemically modified gold thin films in real time. The single-nanoparticle SPRI responses, ∆%RNP, from several hundred adsorbed nanoparticles are collected in a single SPRI adsorption measurement. Analysis of ∆%RNP frequency distribution histograms are used to provide information on the size, material content, and interparticle interactions of the polymer, hydrogel, and protein nanoparticles. These analyses include the measurement of lognormal ∆%RNP distributions for mixtures of polystyrene nanoparticles, the quantitation of bioaffinity uptake into and aggregation of three types of porous poly(N-isopropylacrylamide) hydrogel nanoparticles (including carbohydrate-incorporated and DNA-incorporated hydrogels) specifically engineered to bind peptides and proteins, and the characterization of the negative single-nanoparticle SPRI response and lognormal ∆%RNP distributions obtained for three different types of genetically encoded gas-filled protein nanostructures derived from bacteria