Synthesis and study of fluorescent sensors for Fe(II)
Incardona, Kirsten J.
MetadataShow full item record
The human body has an essential need for metals to sustain function and health. In particular, iron is the most abundant transition metal in the body and the focus of this thesis. The average adult has a cellular concentration around 50-100 ?M of labile or mobile Fe(II). When there is a disruption of homeostatic levels of iron in the body, several diseases may result. An excess of Fe(II) may lead to diseases such as Alzheimer's, Parkinson's, Huntington's, and Multiple Sclerosis. Conversely, iron deficiency causes disorders such as anemia. In order to observe iron accumulations, research into the trafficking and distribution pathways of Fe(II) within the brain or possible labile pools is critical. Analysis of these pathways is made possible by the development of a fluorescent sensor for Fe(II). Three new ligands were synthesized towards the development of an Fe(II) turn- on sensor. These ligands are comprised of a dansyl fluorophore attached to a linear chelate with additional pendants consisting of methyl pyridine, pyridine and triazole moieties. The triazole pendants were chosen as donor groups that have been minimally studied, while the methyl pyridine and pyridine ligands were analyzed for comparison. The ligands were studied for metal ion binding selectivity of Fe(II) over Fe(III) and Zn(II) using fluorescence spectroscopy. Data show that the methyl pyridines are most promising for binding Fe(II) and the pyridine and triazole ligands are promising for binding Fe(III). All three ligands show favorable binding of Fe(II) over Zn(II) near physiological pH of 7.50 as well as pH 7.00 for all of the sensors. Fluorescent quenching was seen for Fe(II), Fe(III) and Zn(II) for the methyl pyridine and triazole pendants. The pyridine ligand also displayed fluorescent quenching for Fe(II) and Fe(III), however increased the fluorescence intensity for Zn(II). This indicates a possible turn-on sensor for Zn(II). With continued research these data indicate advancement towards an improved fluorescent sensor with selectivity for Fe(II).