Date of Award
Doctor of Philosophy (PhD)
Chieu D. Tran
Jeanne M. Hossenlopp
In this work, we explore novel analytical applications of Ionic Liquids and Near-infrared multispectral imaging microscopy.
Ionic liquids (ILs) belong to a group of organic salts that are liquid at room temperature and can be, due to their unique chemical and physical properties, successfully used for a variety of applications. The main goal of this study was to explore the synergistic use of ILs in chemical separations. Specifically, chiral ILs were used as novel chiral selectors for Capillary Electrophoresis and as solvents for stationary phase in Gas Chromatography. As chiral selectors IL provides baseline-separation as well as enantiomeric separation of pharmaceutical compounds, including (R)- and (S)-ibuprofen and flurbiprofen. ILs facilitated preparation of novel cavitand-impregnated ionic liquid stationary phase that can effectively separate different types of analytes, including a mixture of xylene isomers and isotopic isomers of methanol, chlorobenzene, dichlorobenzene, pyridine and 1,4-dioxane.
Near-infrared multispectral imaging (NIR-MSI) microscope was used to visualize and characterize individual gold nanoshells and nanocages as well as individual poly(N-isopropylacrylamide-co-acrylic acid) (NIPAM-co-AAc) hydrogel particles (with and without gold nanocages). Localized Surface Plasmon Resonance (LSPR), and its dependence on the dielectric constant of the medium, of individual gold nanoshells were successfully determined for the first time using the NIR-MSI microscope. The NIR-MSI microscope was also successfully used to determine Lower Critical Solution Temperature (LCST) phase transition of individual poly(NIPAM-co-AAc) hydrogels.
In addition to the applications of the NIR-MSI instrument described in the preceding paragraph, the NIR-MSI microscope was also used for classification of non-melanoma skin cancers. Specifically, both NIR and visible images as well as absorption spectra of Basal Cell Carcinoma, Squamous Cell Carcinoma and Seborrheic Keratosis (benign tumor) can be obtained by use of the microscope. Subsequent treatment of multispectral images obtained with statistical processing tools such as Linear Discriminant Analysis (LDA) made it possible to accurately diagnose different types of skin cancers.