Physical Sciences and Mathematics Commons^™

Progress Toward Synthesis Of Molecular Beacons Incorporating Dabcyl Analog Quenchers, Christie M. Ettles

Electronic Thesis and Dissertation Repository

Progress toward the synthesis of molecular beacons containing analogs of the universal quencher 4-(4'-dimethylaminophenylazo)benzoic acid (DABCYL) has been made. A synthetic methodology has been developed for the differential labeling of a PNA molecular beacon with quencher and fluorophore moieties. A DABCYL analog diarylazo compound and three small fluorescent molecules have been derivatized with terminal alkyne groups for incorporation into azide-decorated PNA oligomers by on-resin “click” chemistry. An optimized on-resin procedure was used to determine the viability of the fluorophores and quencher for incorporation into PNA.

The synthesis of a pyrrolocytidine phosphoramidite containing a diarylazo DABCYL analog moiety was undertaken with …

Zinc Chemical Biology: The Pursuit Of The Intracellular Targets Of Zinquin, Andrew Nowakowski

Theses and Dissertations

Fluorescent sensors have been a main microscopic tools used to understand Zn2+ physiology on a cellular level. The use of the fluorescent Zn2+ sensor Zinquin (ZQ) and its analogues have revealed that transient Zn2+ is a chief component in a variety of biochemical pathways. Yet, little work has been performed to validate the exact targets of Zinquin in a cellular environment. The goals of this investigation are to determine the types of Zinquin reactions that take place in the cell as well as the identities of its cellular targets.

It has been hypothesized that Zinquin reacts with free Zn2+ within …

Fluorescence Spectroscopy With Correlated Atomic Force Microscopy Of Gold Nanoparticles And Meso-Scale Ribbons, Meredith Marie Therrien

Doctoral Dissertations

Studies on the optical properties of gold nanoparticles are of great interest due to the size and shape control and easy adaptability through functionalization to most any application, everything from nanomedicine to nanosensing. Gold nanoparticle optical properties change with size, morphology, and environment. Gold nanospheres were explored to determine the effect of environmental change, from many particles in solution to a single particle immobilized and in air, on fluorescence peak position. A statistical distribution of single gold nanorod fluorescence spectra demonstrate the spectral changes associated with slight variations in size. In solution, gold nanorods self-absorb and only exhibit bulk gold …

An Optical-Fiber Based Sensor Array For The Simultaneous Analysis Of Zinc And Copper In Aqueous Environments, Steven Kopitzke

Theses and Dissertations

Copper and zinc are elements commonly used in industrial applications, with many of these processes using these elements in aqueous environments. Before the solutions can be discharged into civil or native waterways, waste treatment processes must be undertaken to ensure compliance with federal, state and local guidelines restricting the concentration of ions discharged in solution. While there are methods of analysis currently available to monitor these solutions, each method has disadvantages, be it that they are cost prohibitive, inaccurate, and/or time-consuming. In this work, a new optical fiber-based platform capable of providing fast and accurate results when performing solution analysis …

Investigation Of The Orientation Dependence On Chiroptical Properties Of Single Molecules, Austin Joseph Cyphersmith

Open Access Dissertations

Optical activity is the defining property of chiral materials that is essential for characterization in biology, chemistry, and physics. While a substantial body of research has provided a strong theoretical framework of the origin of optical activity, we still know very little by way of experiment about an individual molecule’s contribution to the bulk optical activity. The chiroptical response of a single molecule can depend on molecular orientation and local molecular environment, information which is lost in ensemble averaging.

This thesis focuses on establishing methods for a priori determination of chiral molecule orientations and refining measurements to probe the chiroptical …

Synthesis And Characterization Of New Light Emitting Probes For Sensitive Detection Of Bio-Molecules And Live Cells, Shyamala Pravin Pillai

Dissertations

A variety of contemporary analytical platforms in technical and biological applications take advantage of labeling the objects of interest with fluorescent or luminescent tracers. Luminescent tracers take advantage of the unique property of some lanthanide metals to absorb and emit light. Long lifetime of lanthanide emission allows temporal gating of the signal, which avoids the short-lived background of interfering sample components. This property in combination with large Stokes shift contributes to extreme sensitivity of detection (ca. 10^-13-10^-14 M), which makes lanthanide-based probes suitable for large variety of challenging tasks ( e.g., intracellular detection of single DNA/RNA, or …

Development And Characterization Of Fluorescent Ph Sensors Based On Porous Silica And Hydrogel Support Matrices, Qili Hu

Dissertations, Master's Theses and Master's Reports - Open

The hydrogen ion activity (pH) is a very important parameter in environment monitoring, biomedical research and other applications. Optical pH sensors have several advantages over traditional potentiometric pH measurement, such as high sensitivity, no need of constant calibration, easy for miniaturization and possibility for remote sensing. Several pH indicators has been successfully immobilized in three different solid porous materials to use as pH sensing probes.

The fluorescent pH indicator fluorescein-5-isothiocyanate (FITC) was covalently bound onto the internal surface of porous silica (pore size ~10 nm) and retained its pH sensitivity. The excited state pK* _a of FITC in porous silica …

Synthesis Of 1-Pyrenyldiazomethane For Derivatization Of Short-Chain Fatty Acids, Mary E. Kalvaitis

Senior Honors Theses and Projects

Use of I-pyrenyldiazomethane (PDAM) for derivatizing short-chain fatty acids (SCFA) is a successful way to analyze complex SCF A samples quickly and with minimal sample preparation. The costs associated with ordering PDAM from a commercial source can be high, typically more than $300 not including shipping costs. This project developed a simple two-step synthesis procedure that can be used in undergraduate chemistry laboratories. We found that the PDAM produced by this procedure is pure enough to use for our derivatization needs without further purification. This synthesis can be used to further explore the use of PDAM for fast and simple …

Gumbos And Nanogumbos: Applications As Photosensitizers In Dye-Sensitized Solar Cells, Atiya Nicole Jordan

LSU Doctoral Dissertations

Renewable energy is a major concern due to increased world energy consumption. In particular, solar energy is a type of renewable energy source that uses devices known as solar cells to convert sunlight to electricity. Specifically, devices referred to as dye-sensitized solar cells (DSSCs) employ dyes to absorb solar energy. Dyes derived from ruthenium complexes have been typically used in DSSCs. Unfortunately, several disadvantages are associated with current ruthenium complex photosensitizers, which can be attributed to limited supply and expense of metals, as well as reduced absorption in the near-infrared region of the electromagnetic spectrum. Accordingly, this dissertation is a …