Increased blood plasma concentrations of the aminothiol homocysteine (Hcy) are associated with a variety of disease states including those which cause impaired renal function, many forms of cardiovascular disease, and neurodegenerative diseases such as Alzheimer's. Therefore, Hcy has the potential to be a significant diagnostic biomarker. Routine monitoring of Hcy plasma concentration is encumbered by the time and resources required to quantify Hcy using currently accepted instrumental analysis methods. As part of the continuing effort to develop a quick, reliable, inexpensive, and user-friendly test to quantify Hcy at the point of care, we have designed a series of novel colorimetric and fluorescent chemical probes based on bridged viologen structures. The absorbance at 540 nm for the para-bridged bis-nitrile viologen probe (pCN) was found to be proportional to the concentration of Hcy analyte, with LOD = 2.17 μM and LOQ = 6.10 μM where unhealthy Hcy plasma concentrations are > 15 μM. The mechanism of reactivity between pCN and Hcy encompasses a dynamic set of reactions which involve pimerization of radical probe species and thioether adduct formation of pCN with Hcy. Preliminary results with fluorometric analogs of the bridged viologen probes are also presented.
| Identifer | oai:union.ndltd.org:pdx.edu/oai:pdxscholar.library.pdx.edu:open_access_etds-2540 |
| Date | 10 January 2014 |
| Creators | Rautiola, Davin |
| Publisher | PDXScholar |
| Source Sets | Portland State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Dissertations and Theses |
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