Chemistry Commons^™

Single Fluorogens And Orientation-Localization Microscopy For Quantifying Chemical And Biomolecular Dynamics At The Nanoscale, Yiyang Chen, Yuanxin Qiu, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Many chemical systems look uniform only because ensemble measurements average over their most interesting molecules. Electron-transfer rates vary across electrode surfaces; lipid membranes contain nanodomains with distinct packing and fluidity; peptide aggregates exhibit local polymorphism; and biomolecular condensates contain transient networks of interactions that are blurred in ensemble images. A central challenge in chemical imaging is not simply to see smaller structures, but to measure chemical variables such as polarity, redox potential, and molecular confinement at the single-molecule level. In this Account, we describe how fluorogens, molecules whose brightness, blinking, spectral shifts, orientation, rotational mobility, and motion are directly shaped …

Research Instrumentation Center (Ric), Ryan Hilger, Purdue University Office Of Research

University Research Core Facility Boilerplate Descriptions

No abstract provided.

Chemometric Analysis Of Dissolved Organic Matter Using Fluorescence, Dani Fellner, Ken Overway

Honors Projects

Univariate spectroscopic techniques have been utilized to measure dissolved organic matter (DOM), but challenges arise in the separation and characterization due to similarities in chemical structures and spectral overlap. Multivariate techniques utilize a combination of known analytes with their unique excitation and emission spectra from fluorescence measurements to quantify amount of each analyte present in the mixture using parallel factor analysis. Tryptophan, tyrosine, and phenylalanine are common amino acids found in environmental samples and can be quantified due to their intrinsic fluorescence qualities. These amino acids can be utilized to estimate the amount of DOM in a sample since proteins …

Limit Of Detection Variations In Polyphenol Mixtures Using Parafac-Feem Spectroscopy, Ken Overway, Brockton Zorn

Honors Projects

Polyphenols are chemical compounds commonly found in food products like olive oil and red wine. Research suggests that their presence in such foods conveys positive cardiovascular and cognitive health benefits. This group of compounds is often difficult to quantify in such samples due to an overlap in the chemical signals and the presence of interferences, such as coloring, found naturally in the food. Use of 3D Fluorescence Excitation Emission Matrix (EEM) measurements combined with pH sensitivity could establish a method in which polyphenols are identified more easily in mixtures. Binary and ternary mixtures of polyphenols were analyzed without the additional …

Synthesis And Photophysical Studies Of Coumarin-Quinoline Derivatives, Nishrenika Pokhrel

Honors Theses

A new family of oxime-functionalized coumarin-quinoline derivatives, 5a and 5b, has been synthesized through a five-step procedure in high yields (45-98%). Compound 5a is designed as the sensing probe, while 5b serves as a model system to support mechanistic understanding. The sensing approach is based on the reactivity of the oxime group, which can undergo phosphorylation in the presence of organophosphate nerve agents. Based on this behavior, it is hypothesized that 5a can react irreversibly with a nerve agent mimic. The structures were fully characterized by NMR, FTIR, and HRMS. Photophysical properties of 5a were studied in various solvents, …

Selective Reversal Of Cu-Amyloid Aggregation Monitored In Real Time By Fluorescence Anisotropy: Ni-Bme-Dach Vs Edta Benchmarks, Alyssa N. Schroeder, Eleanor K. Adams, Dane C. Frost, Erica Lopez, Jennie R. Giacomini, Marilyn R. Mackiewicz

Chemistry Faculty Publications and Presentations

Metal dyshomeostasis, particularly involving Cu2+, is increasingly recognized as a key contributor to amyloid-β (Aβ) aggregation and neurotoxicity in Alzheimer’s disease, motivating the development of chelators capable of selectively disrupting pathogenic metal-Aβ interactions without perturbing essential biological metals. Here, we employ steady-state fluorescence anisotropy as a real-time probe of TAMRA-Aβ1–42 rotational mobility to quantify metal-induced aggregation and its reversibility by two chelators with distinct selectivities: EDTA, a broad-spectrum benchmark, and Ni-bme-dach, a sulfur-rich metallodithiolate with high Cu affinity. Cu2+ induces the most significant increases in anisotropy, consistent with rapid formation of large nanoscale aggregates, while Fe3+ produces moderate aggregation and …

Surface Chemistry-Dependent Binding Interactions Between Kraft Lignin And Polyelectrolyte-Encapsulated Gold Nanoparticles, Oluwaseun Ayodeji Akinsola, Samuel Lohse

All Faculty Scholarship for the College of the Sciences

This study investigated the relationship between gold nanoparticle (AuNP) surface chemistry and the binding affinity of unfractionated kraft lignin to polyelectrolyte-coated AuNPs. Specifically, fluorescence quenching titrations were employed to determine lignin’s binding affinity (K_a) to different charged polymer surfaces displayed on 90 nm citrate-stabilized AuNPs, (poly(allylamine hydrochloride)) (PAH), polyacrylate (PAA), and poly(diallyldimethylammonium chloride) (PDADMAC). AuNP–lignin conjugates were characterized by UV–vis absorbance spectroscopy, ζ-potential analysis, and dynamic light scattering (DLS) measurements. The characterization data showed that the size, surface charge and aggregation state of the lignin–AuNP conjugates depended on the original surface chemistry of the AuNP, in conjunction …

Pentanary And Hexanary Alkali Lanthanide Germanates Grown From Lanthanide Rich Flux Growth Reactions, Gregory Morrison, K. Pilar Zamorano, Virginia G. Jones, Ethan N. Adams, Hans Conrad Zur Loye

Faculty Publications

Single crystals of five compounds of a new structure type, the K3Nd52Ge12O100F7 type, were grown from lanthanide rich reactions using a KF/KCl flux: K3Ln52Ge12O100F7 (Ln = Nd, Eu), K3Ln52Ge12O100+δF7-δ (Ln = Pr, Tb), and K3Ca0.872Nd51.128Ge12O99.128F7.872. The five compounds crystallize in the cubic space group I-43d with lattice parameter 22.0350(2) Å for K3Nd52Ge12O100F7. The structure consists of a 3D checkerboard of LnX8, LnX7, LnX6, and GeO4 polyhedra, where X = O/F, and can be conceptually derived from the fluorite structure. K3Eu52Ge12O100F7 exhibits the fluorescence typical of Eu³⁺.

Low-Cost Cutaneous Protoporphyrin Ix (Ppix) Detection (Cpd) Device For Follow-Up Monitoring Of Patients After Photodynamic Therapy, Md Asaduzzaman Rasel

Graduate Masters Theses

Background: Photodynamic Therapy (PDT) utilizes specific wavelengths of light to activate photosensitizing chemical compounds, known as photosensitizers, which induce the generation of cytotoxic reactive oxygen species (ROS) for the targeted destruction of cancer cells. Among various photosensitizers for PDT, Protoporphyrin IX (PpIX) is widely employed in oncology and dermatology due to its natural in situ generation via the metabolic conversion of 5- aminolevulinic acid (ALA), a non-phototoxic prodrug. Systemic administration of ALA after 3-6 hr drug delay leads to peak PpIX accumulation in tissues, facilitating therapeutic and diagnostic applications. However, PpIX can persist in the skin for 24–48 hours post-treatment, …

Development, Optimization, And Validation Of A High-Sensitivity Capillary Zone Electrophoresis System For Bioanalytical Applications, Aaron I. Mena

Electronic Theses and Dissertations

Capillary zone electrophoresis (CZE) is a powerful analytical technique widely used for biomolecular separation due to its high resolution, efficiency, and sensitivity. This report presents the development and validation of a novel CZE system designed to improve modularity, reproducibility, and operational efficiency. The system integrates a laser-induced fluorescence (LIF) detection method with a 488 nm laser, enhanced fluid control through a negative pressure system, and a user-friendly GUI for automated operation and data acquisition. Performance verification included pressure stability tests, fluorescence accuracy assessments, and electrophoretic reproducibility studies. Comparative analysis with a previous CZE iteration confirmed improved baseline stability, peak resolution, …

Studies On The Synthesis, Function, And Properties Of Troponoids, John-Charles A. Baucom

Dissertations, Theses, and Capstone Projects

Troponoids are a unique class of non-benzenoid aromatic compounds with a wide range of demonstrated applications in pharmaceuticals and molecular sensing. The cycloheptatrienone scaffold possesses a noteworthy degree of tunability as a function of ring oxygenation. This manuscript describes our efforts toward a better understanding of the physical consequences of the scaffold to better utilize the motif. Chapter the first discusses our efforts at elucidating the mechanism of troponoid inhibition of the Hepatitis B virus reverse transcriptase RNAse H enzymatic domain. Using homology modeling in conjunction with traditional in vitro assays we were able to establish the likely mechanism of …

Developing Phenanthroimidazole-Based Fluorescent Sensors For Efficient Analyte Detection, Brian Kellogg

Masters Theses & Specialist Projects

The highly efficient design and synthesis of organic fluorophores with an excellent quantum yield have received extensive attention. Compared with instrumental techniques, fluorescent sensors derived from organic small molecules offer many impressive benefits, such as selective detection, lower cost, and higher efficiency. Various detection mechanisms such as colorimetric, ratiometric, and fluorescence turn on/off have been reported for single analyte detection. Developing molecular probes that are capable of detecting two (or more than two) different analytes (cations, anions, and/or biomolecules) had emerged as a new research area and attracted considerable attention in the field of chemo- and biosensors.

Phenanthroimidazole represents a …

Synthesis Of Noval Hydroxy Chalcone And Study Of Fluorescent Properties, Margaret Hilliker

Williams Honors College, Honors Research Projects

Chalcones are a class of naturally occurring compounds found in plants, which have a general structure of Ar–CO–CH=CH–Ar’. They have shown significant potential as tunable organic fluorophores due to their extended π-conjugation and structural simplicity. In this study, a 2-hydroxy-substituted chalcone featuring a terminal dimethylamino group was synthesized via a pyrrolidine-catalyzed aldol condensation and characterized for its photophysical properties. The electron-donating and -accepting ends of the molecule establish an intramolecular charge transfer (ICT) pathway, while the hydroxyl group enables excited state intramolecular proton transfer (ESIPT), leading to complex emission behavior. Room temperature fluorescence analysis revealed broad, featureless emission, while low-temperature …

Microwave Assisted Syntheses And Characterizations Of Near-Infrared Ratiometric Probes For Mitochondrial Ph Detection And Monitoring, Ronald J. Schwandt

Dissertations, Master's Theses and Master's Reports

Within the field of biochemistry, there has been a significant development of ratiometric fluorescent probes designed for mitochondrial pH detection; however, many of these probes have emissions within the visible spectrum and require long synthesis times with low-yield reactions. However, in recent years, microwave-assisted syntheses of organic molecules have led to significant increases in reaction yields and quicker reaction times. In this work, two common reactions in probe synthesis, Heck coupling, and Knoevenagel condensations are investigated using microwave-assisted synthesis. It was found the low-concentration Heck coupling reactions using palladium (II) acetate led to extremely efficient Heck coupling. Also, a novel …

Near-Infrared Ratiometric Hemicyanine Fluorescent Probes For Monitoring Mitochondrial Ph Dynamics In Live Cells During Oxidative Stress And Hypoxia, Sushil K. Dwivedi, Dilka Liyana Arachchige, Adenike Olowolagba, Mohamed Mahmoud, Subash Pandey, Tara Vohs, Haiying Liu, Rudy Luck

Michigan Tech Publications

Novel near-infrared ratiometric molecules (probes A and B) produced by linking formyl-functionalized xanthene and methoxybenzene moieties, respectively, onto a xanthene-hemicyanine framework are detailed. Probe A exhibited a primary absorption peak at 780 nm and a shoulder peak at 730 nm and exhibited fluorescence at 740 nm↓ (signifies a downward shift in intensity upon acidification) in a pH 9.3 buffer and 780 nm↑ at pH 2.8 under excitation at 700 nm. Probe B featured absorptions at 618 and 668 nm at pH 3.2 and at 717 nm at pH 8.6, and fluorescence at 693 nm↑ at pH 3.2 and at 739 …

Enhancing Cardiomyocyte Resilience To Ischemia-Reperfusion Injury: The Therapeutic Potential Of An Indole-Peptide-Tempo Conjugate (Iptc), Shanshan Hou, Xin Yan, Xiang Gao, Steffen Jockusch, K. Michael Gibson, Zhiying Shan, Lanrong Bi

Michigan Tech Publications

Ischemia/reperfusion (I/R) injury leads to apoptosis and extensive cellular and mitochondrial damage, triggered by the early generation and subsequent accumulation of mitochondrial reactive oxygen species (mtROS). This condition not only contributes to the pathology of I/R injury itself but is also implicated in a variety of other diseases, especially within the cardiovascular domain. Addressing mitochondrial oxidative stress thus emerges as a critical therapeutic target. In this context, our study introduces an indole-peptide-tempo conjugate (IPTC), a compound designed with dual functionalities: antioxidative properties and the ability to modulate autophagy. Our findings reveal that IPTC effectively shields H9C2 cardiomyocytes against hypoxia/reoxygenation (H/R) …

Fundamental Limits In Measuring The Anisotropic Rotational Diffusion Of Single Molecules, Weiyan Zhou, Tingting Wu, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Many biophysical techniques, such as single-molecule fluorescence correlation spectroscopy, Förster resonance energy transfer, and fluorescence anisotropy, measure the translation and rotation of biomolecules to quantify molecular processes at the nanoscale. These methods often simplify data analysis by assuming isotropic rotational diffusion, e.g., that molecules wobble within a circular cone. This simplification ignores the anisotropy present in many biological contexts that may cause molecules to exhibit different degrees of diffusion in different directions. Here, we loosen this assumption and establish a theoretical framework for describing and measuring anisotropic rotational diffusion using fluorescence imaging. We show that anisotropic wobble is directly quantified …

Design, Synthesis And Characterization Of Zinc And Gold-Based Metal-Organic Frameworks And Complexes For The Detection And Treatment Of Cancer, May Reda Mohamed

Thesis/ Dissertation Defenses

The early detection of cancer plays a pivotal role in improving patient outcomes, emphasizing the urgent need for highly sensitive and selective biosensing platforms. Metal-Organic Frameworks (MOFs) have emerged as promising candidates in this domain due to their tunable properties, large surface area, and high porosity. Herein, the utilization of zinc-based MOF as a sophisticated biosensing platform tailored for the precise detection of the HER2 cancer biomarker is presented. HER2, a critical protein marker in breast cancer diagnostics and treatment, demands highly selective and accurate detection methods for effective patient management. Simple hydrothermal synthesis methodology has been adopted to synthetize …

Design, Synthesis And Characterization Of Zinc And Gold-Based Metal Organic Frameworks And Complexes For The Detection And Treatment Of Cancer, May Reda Mohamed

Dissertations

The early detection of cancer plays a pivotal role in improving patient outcomes, emphasizing the urgent need for highly sensitive and selective biosensing platforms. Metal-Organic Frameworks (MOFs) have emerged as promising candidates in this domain due to their tunable properties, large surface area, and high porosity. Herein, the utilization of zinc-based MOF as a sophisticated biosensing platform tailored for the precise detection of the HER2 cancer biomarker is presented. HER2, a critical protein marker in breast cancer diagnostics and treatment, demands highly selective and accurate detection methods for effective patient management. Simple hydrothermal synthesis methodology has been adopted to synthetize …

Modification, Transport, And Sources Of Hydrocarbon Oxidation Products From Groundwater At Crude Oil And Diesel Spill Sites In Minnesota: Unveiling Common “Theems” Via Spectroscopy & Chromatography, Eduardo E. Turcios Valle

LSU New Orleans Theses and Dissertations

In this thesis, petroleum-contaminated groundwater from three spill-affected Minnesota sites—two contaminated with crude oil; one with diesel—is investigated to elucidate whether differences in degradation products from different parent oils exist. After spill events, parent molecules from the leaked oil seep underground and undergo microbial degradation over time, transforming into hydrocarbon oxidation products (HOPs), water-soluble contaminants that infiltrate groundwater aquifers, flowing into nearby environments and towns while exhibiting environmental persistence, toxicity to aquatic biota, and potential risks to humans that become exposed. Spectroscopic and chromatographic study of the structural themes and spatial distributions of HOPs reveals preferential degradation of aliphatic (biolabile) …

Chemical Composition, Fate, And Toxicity Of Dissolved Hydrocarbon Oxidation Products In High Latitude Aquatic Environments, Maxwell Louis Harsha

LSU New Orleans Theses and Dissertations

Oil spilled in aquatic environments undergoes abiotic and biotic oxidation processes that produce hydrocarbon oxidation products (HOPs). HOPs rapidly diffuse in the water column, persisting and readily bioavailable to aquatic organisms. Characterizing HOPs is challenging because most of the mixture resides in the unresolved complex mixture (UCM). Understanding of the formation, fate, and toxicity of HOPs in high latitude environments remains limited. This research addresses these gaps through a comprehensive experimental approach, utilizing various analytical techniques including nonvolatile dissolved organic carbon (NVDOC) analysis, ultrahigh-resolution mass spectrometry, tandem mass spectrometry, inductively coupled plasma mass spectrometry, and fluorescence excitation-emission matrix spectroscopy. Additionally, …

Use Of Dft Calculations As A Tool For Designing New Solvatochromic Probes For Biological Applications, Cynthia M. Dupureur

Educator Preparation & Leadership Faculty Works

The intramolecular charge transfer behavior of push–pull dyes is the origin of their sensitivity to environment. Such compounds are of interest as probes for bioimaging and as biosensors to monitor cellular dynamics and molecular interactions. Those that are solvatochromic are of particular interest in studies of lipid dynamics and heterogeneity. The development of new solvatochromic probes has been driven largely by the need to tune desirable properties such as solubility, emission wavelength, or the targeting of a particular cellular structure. DFT calculations are often used to characterize these dyes. However, if a correlation between computed (dipole moment) and experimentally measured …

Examining The Effectiveness Of Oiled Ballast Water Treatment Processes: Insights Into Hydrocarbon Oxidation Product Formation And Environmental Implications, Maxwell L. Harsha, Danielle E. Verna, Yanila Salas-Ortiz, Eduardo Osborn, Eduardo Turcios Valle, Aleksandar I. Goranov, Patrick G. Hatcher, Ana M. Aguilar-Islas, Patrick L. Tomco, David C. Podgorski

Chemistry & Biochemistry Faculty Publications

Ballast water released from ships into coastal environments has been identified as a mechanism that introduces contaminants of concern into coastal ecosystems. This study investigates the treatment processes employed at a ballast water treatment facility in Valdez, Alaska, that remove hydrocarbons from unsegregated ballast water. Specifically, the aim is to quantify and characterize hydrocarbons of emerging concern, known as dissolved hydrocarbon oxidation products (HOPs) and heavy metals (HMs), throughout the treatment process. Specialized analytical techniques were employed, such as non-volatile dissolved organic carbon analysis, fluorescence spectroscopy, Fourier transform-ion cyclotron resonance-mass spectrometry, and inductively coupled plasma triple quadrupole mass spectrometry. Results …

Unexpected Ring Opening Reactions, Solid-State Structures, And A Chemiluminescent Reaction, L Hiscock

Theses and Dissertations (Comprehensive)

Functional π-materials involve the use of an aromatic π-system to carry out a function such as electron transport (organic electronics), absorbing and emitting photons (dyes, fluorescent materials), self-assembly (discotic liquid crystals), or sensors for various analytes. Our lab has recently published the syntheses of heteroaromatic derivatives of tetrafluoroterephthalonitrile (TFTP, 2.24) synthesised via nucleophilic aromatic substitution chemistry. The prepared derivatives have displayed fluorescent (e.g. 2.2)1 and liquid crystalline (1.0)2 properties, as well as displaying close π-π interactions in the solid state (2.8).3 As the materials we are synthesising all belong to the class of aromatic compounds, an introduction to aromaticity and …

Coordination Chemistry Using Strategic Design Of Ligands For Switchable Properties, Delara Joekar

Theses and Dissertations (Comprehensive)

Coordination-driven self-assemblies are multifunctional molecular systems that provide an efficient method for miniaturization towards functional devices with diverse applications. Herein, the synthesis of novel pyrazole-based ligands suitable for construction of coordination assemblies is reported. These were designed using a strategy that incorporates the presence of both cationic and anionic coordination sites, and a third site for further functionalization. This design strategy has been used because there is still a knowledge gap for controlling the directionality of weak molecular forces in the presence of stronger competing forces. The structural characterization of these ligands, their Hirshfeld surface analysis, and select coordination complexes …

Engineering Exosomes To Specifically Target The Mitochondria Of Brain Cells, Xin Yan, Xinqian Chen, Zhiying Shan, Lanrong Bi

Michigan Tech Publications

Mitochondrial dysfunction is associated with various health conditions, including cardiovascular and neurodegenerative diseases. Mitochondrial-targeting therapy aims to restore or enhance mitochondrial function to treat or alleviate these conditions. Exosomes, small vesicles that cells secrete, containing a variety of biomolecules, are critical in cell-to-cell communication and have been studied as potential therapeutic agents. Exosome-based therapy has the potential to treat both cardiovascular and neurodegenerative diseases. Combining these two approaches involves using exosomes as carriers to transport mitochondrial-targeting agents to dysfunctional or damaged mitochondria within target cells. This article presents a new technique for engineering brain-derived exosomes that target mitochondria and has …

Engineering Exosomes To Specifically Target The Mitochondria Of Brain Cells, Xin Yan, Xinqian Chen, Zhiying Shan, Lanrong Bi

Michigan Tech Publications

Mitochondrial dysfunction is associated with various health conditions, including cardiovascular and neurodegenerative diseases. Mitochondrial-targeting therapy aims to restore or enhance mitochondrial function to treat or alleviate these conditions. Exosomes, small vesicles that cells secrete, containing a variety of biomolecules, are critical in cell-to-cell communication and have been studied as potential therapeutic agents. Exosome-based therapy has the potential to treat both cardiovascular and neurodegenerative diseases. Combining these two approaches involves using exosomes as carriers to transport mitochondrial-targeting agents to dysfunctional or damaged mitochondria within target cells. This article presents a new technique for engineering brain-derived exosomes that target mitochondria and has …

Fluorescent Molecular Rotors As Versatile In Situ Sensors For Protein Quantitation, Kevin Daus, Sorachat Tharamak, Wanchai Pluempanupat, Peter Galie, Maria A Theodoraki, Emmanuel A Theodorakis, Mary Alpaugh

College of Science & Mathematics Departmental Research

Accurate protein quantitation is essential for many cellular mechanistic studies. Existing technology relies on extrinsic sample evaluation that requires significant volumes of sample as well as addition of assay-specific reagents and importantly, is a terminal analysis. This study exploits the unique chemical features of a fluorescent molecular rotor that fluctuates between twisted-to-untwisted states, with a subsequent intensity increase in fluorescence depending on environmental conditions (e.g., viscosity). Here we report the development of a rapid, sensitive in situ protein quantitation method using ARCAM-1, a representative fluorescent molecular rotor that can be employed in both non-terminal and terminal assays.

Binding Interactions Of Biologically Relevant Molecules Studied Using Surface-Modified And Nanostructured Surfaces, Palak Sondhi

Dissertations

This research focuses on the field of surface nanobioscience, wherein different nanosurfaces that will be used as working electrodes in the electrochemical cell are manufactured and surface modified to understand the critical binding interactions between biologically significant molecules like proteins, carbohydrates, small drug molecules, and glycoproteins. This research is essential if we are to determine whether a synthetic molecule can serve as a therapeutic candidate or diagnose a disease in its early stages. In order to fully understand the binding interactions, the study begins with defining some of the fundamental concepts, principles, and analytical tools for biosensing.

Afterwards, we addressed …

Synthesis, Characterization, And Photophysical And Fluorescence Sensor Behaviors Of A New Water-Soluble Double-Bridged Naphthalene Diimide Appended Cyclotriphosphazene, Süreyya Oğuz Tümay, Serkan Yeşi̇lot

Turkish Journal of Chemistry

A new water-soluble template of double-bridged naphthalene diimide appended cyclotriphosphazene was prepared, and its photophysical and sensor behaviors were evaluated. The characterization of novel double-bridged naphthalene diimide appended cyclotriphosphazene (6) was carried out by NMR (1 H, 13C, 31P) and mass spectroscopies. The photophysical behaviors of compound 6 were evaluated by UV-Vis absorption and fluorescence spectroscopies in various solvent systems and different concentrations. As an application for usability of the obtained water-soluble template in different applications, the fluorescence sensor property of compound 6 was investigated in the presence of many different competing species (organic acids, saccharides, nitroaromatic compounds, anions, and …