| Description |
In recent years, plasmonic in the ultraviolet (UV) region has been promising due to numerous applications in bioscience and material science. Almost all biological molecules present some level of intrinsic fluorescence in the ultraviolet range of the spectrum. Enhancement of intrinsic emission of proteins and other biomolecules can be achieved through metal surface plasmon resonance (SPR) in the UV region, contributing to a labelfree detection. Despite its ability to achieve label-free molecularly recognition and quantification, the applications of UV plasmonic for biosensing have been limited due to challenges in engineering (nanostructure design, optimization, and fabrication) and materials science. The signal level of intrinsic fluorescence is still orders of magnitude less than that of organic dye molecules in a fluorescence-labeled assay. For UV plasmonic material, aluminum has a relatively large quality plasmonic factor. Such properties enable strong SPR across the UV and visible region. Therefore, this dissertation primarily discusses UV plasmonic sensors to detect native fluorescence of biomolecules, and photodecomposition properties and suggests a novel platform for monitoring neurotransmitters. The first part discussed the fabrication and optimization of plasmonic structures and the analysis enhancement factor. The optimized aluminum nanohole platform achieved approximately 50-fold net enhancement and observed photodecomposition by the light source. Plasmonic structure about 2 times reduces the photobleaching rate and the iv photobleaching rate depends on which molecule it is and from which substrate the molecules are excited. The second part focuses on neurotransmitter monitoring. Analyzed photobleaching rate of neurotransmitters and provide clues to distinguish similar molecules. Novel aptamer-based SPR experiments were performed and characterized the binds between aptamer and neurotransmitters. Aptamers through a DNA linker hybridized can capture the dopamine and the designed assay has a high binding affinity with dopamine compared to norepinephrine. The last part introduced the numerical design of an insulator-based dielectrophoresis microchannel that can capture exosomes, nanoscale biomolecules, and separate them according to size. In addition, demonstrated further plan for developing realtime sensing by combining microfluidic channel with UV plasmonic platform. |
