Particle-Based Platforms for Analytical Applications

Different biomolecules play distinct and crucial roles in biological systems. The capability to quantify and analyze these biologically important species is essential to the fundamental understanding of biochemical pathways, processes, and interactions. This requirement has stimulated the development of sensitive and selective probes, sensors, and assays for the detection and measurement of biologically relevant molecules. Many biologically inspired sensors and delivery platforms are designed utilizing phospholipid nanoshells due to their special architecture and biocompatibility. For molecules that lack fluorescent or electrochemical activity, the use of radiolabeling can be applied to maintain the chemical structure, physical properties, and biological activity of labeled molecules while providing a unique signal for detection. Among different radioassays, scintillation proximity assay (SPA), utilizing stable, functionizable particle-based scintillant platforms with efficient scintillant responses, has proven to be a sensitive, selective, separation-free technique that capitalizes on the advantages of radiolabeling. The work in this dissertation describes efforts in fabrication of polymeric scintillant particle platforms for application in low-energy radioisotope detection and stabilization of phospholipid nanoshells and their long-term behavior studies. Facile and direct polymerization methods were used to fabricate nanometer- to micron-sized polymeric particles that possessed stable scintillant matrices. Vinyl-functionalized primary scintillant fluorophores were polymerized within a copolymerized matrix to form scintillant microparticles. Subsequently, copolymer core-silica shell scintillant microparticles were prepared and functionalized with various recognition moieties, demonstrating their applicability for SPA development. The inclusion of polymerizable secondary scintillant fluorophores in terpolymer scintillant microparticles further improved scintillation