Doctor of Philosophy (PhD)
The work presented in this dissertation employs task-specific materials for sensing and protein separation applications. These materials were derived from a group of uniform materials based on organic salts (GUMBOS). GUMBOS are organic salts similar to ionic liquids, but have melting points ranging from 25 to 250 °C. As with ionic liquids, the properties of GUMBOS can be easily tuned by changing the counter-ion. Thus, task-specific GUMBOS can be designed and prepared with properties that are beneficial for applications in sensing or protein separation. In this dissertation, the selective responsive behavior of a series of GUMBOS and nanomaterials derived from GUMBOS (nanoGUMBOS) were evaluated. Firstly, binary nanoGUMBOS, containing two cyanine cations, were synthesized and characterized. Based on significant spectral overlap and differences in reactivity towards hydroxyl radicals, the two cyanine cations in the binary nanoGUMBOS were able to generate a ratiometric fluorescence response. These results suggest a promising ratiometric probe for detection and quantification of hydroxyl radicals. This approach of investigating binary nanoprobes will serve as the basis for designing other cyanine-based fluorescent probes for biosensing and imaging. Secondly, a series of cyanine-based GUMBOS were combined to serve as a sensor array for detection of proteins. The cyanine-based sensor elements utilized in this sensor array, exhibit different aggregation behaviors when mixed with the seven proteins, giving various fluorescence responses. The resulting responses exhibited cross-reactive patterns, which can be analyzed to discriminate proteins at a low concentration. Finally, nanoGUMBOS derived from imidazolium ionic liquids and magnetic dysprosium-based anions were designed as magnetic, nanoadsorbent materials for selective hemoglobin isolation. These nanoGUMBOS were successfully applied in selective hemoglobin (Hb) isolation from human whole blood. All studies presented in this dissertation demonstrate promising advantages of GUMBOS-based materials in the field of sensing and protein separation.
Cong, Mingyan, "Design and Application of Task-Specific GUMBOS and NanoGUMBOS for Sensing and Separation" (2018). LSU Doctoral Dissertations. 4719.
Available for download on Thursday, October 31, 2019