Chemistry Commons^™

Cucurbit[7]Uril-Tetramethylrhodamine Conjugate For Direct Sensing And Cellular Imaging, Andrew T. Bockus, Lauren C. Smith, Amy G. Grice, Omar A. Ali, Carolyn C. Young, William Mobley, Ashley Leek, James Lewis Roberts, Brittany Vinciguerra, Lyle D. Isaacs, Adam R. Urbach

Chemistry Faculty Research

This paper describes the design and synthesis of a conjugate (Q7R) comprising the synthetic host cucurbit[7]uril (Q7) linked to the fluorescent dye tetramethylrhodamine (TMR), and the characterization of its optical and guest-binding properties as well as its cellular uptake. Q7R was synthesized in two steps from monofunctionalized azidobutyl-Q7 and NHS-activated TMR. The fluorescence of Q7R is quenched upon guest binding, and this observable was used to determine equilibrium dissociation constant (K_d) values. Unexpectedly, the K_d values for guests binding to Q7R and to unmodified Q7 were essentially identical. Therefore, Q7R can directly report binding to Q7 without …

Encapsulation Of Cationic Fluorescent Dyes And Photosensitizers Into The Nanoscopic Domains Of Poly(Ethylene Glycol)-B-Poly(Ε-Caprolactone) Micelles, Zhe Cao

Theses and Dissertations

This study describes an initial systematic investigation on the molecular determinants associated with the effective encapsulation (or lack thereof) of small cationic molecules into the nanoscopic domains of Poly(ethylene glycol)-b-poly(ε-caprolactone) micelles. Out of the seven model dyes investigated here (methylene blue, crystal violet, rhodamine 123, styryl 9M, HITC, DIR and Cardiogreen) only DiR and Cardiogreen were found to partition into the core region of the respective polymeric micelles with a high degree of efficiency. Evidences of weak interactions between styryl 9M and HITC with the corona region of these micelles were also found. No experimental evidences indicating any significant interaction …

A Chemical Sensor For Cyanide, Rachel E. Lambert

Honors Theses

The cyanide ion and its gaseous form, hydrogen cyanide, are extremely toxic. Cyanide impairs cellular respiration by inhibiting cytochrome c oxidase, an enzyme in the electron transport chain, leading to cell death.

In a previous study, we synthesized an optical sensor that detects cyanide selectively. The aim of this project is to increase the sensitivity of this sensor. This can be achieved by utilizing the unique spectroscopic properties of lanthanide ions.

The lanthanide metal (europium or terbium) was added to a coumarin-glycine chemodosimeter in a DMSO solvent system. The sensor was titrated with several monodentate analytes including, nitrate, octylamine, 1-pentanethiol, …

Investigation Of The Interactions Between Pt(Ii) And Pd(Ii) Derivatives Of 5,10,15,20-Tetrakis (N-Methyl-4-Pyridyl) Porphyrin And G-Quadruplex Dna, Navin C. Sabharwal , '14, O. Mendoza, John Michael Nicoludis , '12, Thomas Ruan , '16, J.-L. Mergny, Liliya A. Yatsunyk

Chemistry & Biochemistry Faculty Works

G-quadruplexes are non-canonical DNA structures formed by guanine-rich DNA sequences that are implicated in cancer and aging. Understanding how small molecule ligands interact with quadruplexes is essential both to the development of novel anticancer therapeutics and to the design of new quadruplex-selective probes needed for elucidation of quadruplex biological functions. In this work, UV–visible, fluorescence, and circular dichroism spectroscopies, fluorescence resonance energy transfer (FRET) melting assays, and resonance light scattering were used to investigate how the Pt(II) and Pd(II) derivatives of the well-studied 5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrin (TMPyP4) interact with quadruplexes formed by the human telomeric DNA, Tel22, and by the G-rich sequences …

Fluorescence Of Supported Phospholipid Bilayers Recorded In A Conventional Horizontal-Beam Spectrofluorometer, Elizaveta A. Kovrigina, Evgeni L. Kovrigin

Chemistry Faculty Research and Publications

Supported phospholipid bilayers are a convenient model of cellular membranes in studies of membrane biophysics and protein-lipid interactions. Traditionally, supported lipid bilayers are formed on a flat surface of a glass slide to be observed through fluorescence microscopes. This paper describes a method to enable fluorescence detection from the supported lipid bilayers using standard horizontal-beam spectrofluorometers instead of the microscopes. In the proposed approach, the supported lipid bilayers are formed on the inner optical surfaces of the standard fluorescence microcell. To enable observation of the bilayer absorbed on the cell wall, the microcell is placed in a standard fluorometer cell …

Physical Property Control In Core/Shell Inorganic Nanostructures For Fluorescence And Magnetic Targeting Applications, Stephen K. Roberts

Theses and Dissertations

Nanomaterials show immense promise for the future in numerous areas of application. Properties that are unique from the bulk material and are tunable allow for innovation in material design. This thesis will focus on controlling the physical properties of core/shell nanostructures to enhance the utility of the materials.

The first focus is on the impact of different solvent mixtures during the shell growth phase of SILAR based core/shell quantum dot synthesis is studied. Gaining insight into the mechanism for SILAR growth of core/shell nanoparticles allows improved synthetic yields and precursor binding, providing enhanced control to synthesis of core/shell nanoparticles. The …

Synthesis And Photochromism Of New Asymmetrical Diarylethenes With A Variable Heteroaryl Ring And A Quinoline Unit, Hongyan Xu, Renjie Wang, Congbin Fan, Gang Liu, Shouzhi Pu

Turkish Journal of Chemistry

Three new asymmetrical photochromic diarylethenes containing a variable heteroaryl ring and a quinoline unit were synthesized and their structures were determined by single-crystal X-ray diffraction analysis. Their properties, including photochromism, acidichromism, and fluorescence, were investigated systematically. For these diarylethenes, the one with an indole moiety had the largest absorption maximum, cyclization quantum yield, photoconversion ratio, emission peak, and fluorescent modulation efficiency. In addition, these diarylethenes exhibited an evident dual switching behavior induced by the stimulation of acid/base and UV/Vis. Addition of trifluoroacetic acid to solution of the diarylethenes produced protonated derivatives with notable changes in their absorption spectra. These results …

Studies On Hydroxyl Radical Formation And Correlated Photoflocculation Process Using Degraded Wood Leachate As A Cdom Source, Luni Sun, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

In this study, we examined hydroxyl radical (•OH) formation with respect to photoreactivity of colored dissolved organic matter (CDOM), the Fenton reaction, and photoflocculation using leachate from decaying wood. The relationship between •OH photoproduction rate and leachate optical properties (UV-visible absorption and fluorescence excitation-emission matrices (EEMS)) was studied during irradiation using a UV solar simulator. The results showed that the •OH photochemical formation rate is strongly related to humic-like fluorescence as characterized by parallel factor analysis (PARAFAC), and that these fluorescence components are more photolabile than most of the other CDOM components. Fourier transform infrared spectroscopy (FT-IR) indicated the photodegradation …

Kinetic Decay Of A Polymer/Ink Complex As An O2 Indicator, Becca Hoene

All Master's Theses

Indicator inks are an important part of the continued consumption of packaged goods. This thesis is focused on understanding the kinetics and reaction mechanism for a unique indicator ink that is based upon the oxidation of indigotetrasulfonate (ITS) encapsulated in the polyelectrolyte poly(diallyldimethylammonium chloride) (polyDADMAC). Sodium bisulfite (NaHSO₃) was used as the initial oxygen scavenger and to drive the reduction of the ITS. Studies were predominantly done in solution phase through the dilution of the ink systems. Fluorescence spectroscopy was the primary method used to determine the kinetic decay rates and interaction between the ITS dye molecules and …