Analytical Chemistry Commons^™

One-Step Synthesis Of Pani/Nihcf Hybrid Film Using Unipolar Pulse Electrodeposition And Its Electrocatalytic Reduction Performance For H2O2 Detection, Sen-Liang Liao, Xiu-Min Li, Xiao-Gang Hao, Yan-Hong Wang, Chun-Feng Xue, Yong-Hong Wang

Journal of Electrochemistry

Organic–inorganic hybrid films composed of polyaniline/nickel hexacyanoferrate (PANI/NiHCF) were fabricated on platinum substrates using unipolar pulse one-step electrodeposition. The deposition mechanism of hybrid film was proposed: Due to high potential of unipolar pulse electrodeposition, which avoided the reduction of Fe(CN)₆^3-, the films with high electrocatalytic property and “insoluble” form of NiHCF were achieved. The morphology and composition of PANI/NiHCF hybrid film were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FT-IR). The effect of pulse potential on the electrochemical performance of hybrid film was investigated in detail. Results showed that …

Electrochemiluminescence Imaging Focusing: Array Analysis And Visualization Of Latent Fingerprints, Zhen-Yu Zhou, Lin-Ru Xu, Bin Su

Journal of Electrochemistry

Electrochemiluminescence (ECL) imaging, as a novel and powerful analytical method, possesses many distinct advantages, including simplicity, high controllability, high-throughput and visualization. In recent years, it has been used in developing portable and miniaturized ECL sensor, and made remarkable achievements. In this review, the progress of ECL imaging, focusing on array analysis and visualization of latent fingerprints, has been introduced briefly based on our recent investigations and an attempt has been made to propose the future research trend.

Direct Electrochemistry And Glucose Biosensing Of Glucose Oxidase-Gold Nanoparticles Composite Synthesized By Enzyme Method, Fang He, Xiao-Li Qin, Ying-Chun Fu, Chao Chen, Qing-Ji Xie, Shou-Zhuo Yao

Journal of Electrochemistry

Glucose oxidase (GOx)-gold nanoparticles (AuNPs) composite was synthesized by the one-pot enzyme reaction in the mixture solution of NaAuCl₄, GOx and glucose, and a Nafion/GOx-AuNPs/glassy carbon electrode was fabricated by the cast-coating method to examine the direct electrochemistry of GOx and the biosensing performance on this electrode. Such a GOx-AuNPs composite showed good direct-electrochemistry activity and bioactivity of GOx, probably because the enzyme-mediated AuNPs are close to the redox active centers of GOx. This enzyme electrode exhibited a linear amperometric response to glucose concentration (0.54 mmol·L^-1) at -0.4 V (vs. SCE), and a detection limit of …

Preparation Of Surface Molecularly Imprinted Magnetic Nanoparticles For Hemoglobin Sensing, Chun-Fang Huang, Gui-Hong Yao, Jian-Ding Qiu

Journal of Electrochemistry

Surface molecularly imprinted magnetic nanoparticles (NPs) were prepared by employing dopamine (DA) as a functional monomer, hemoglobin (Hb) as a template, H₂PtCl₆ as an oxidant triggered DA polymerization on the surface of the Fe₃O₄ NPs. The Hb and the formed platinum nanoparticles (PtNPs) were embedded into the polydopamine (PDA). After removal of the Hb, the surface molecularly imprinted magnetic nanoparticles (imprinted Fe₃O₄/PDA-PtNPs) were formed, and then simply immobilized on the magnetic glassy carbon electrode (imprinted Fe₃O₄/PDA-PtNPs/MGCE) for Hb sensing. The imprinted Fe₃O₄/PDA-PtNPs …

Enzyme-Based Dna Electrochemical Biosensors: Recent Trends, Chun-Shui Lin, Yi-Ru Wang, Xi Chen

Journal of Electrochemistry

DNA electrochemical sensors have greatly promoted the development of biosensors for their high sensitivity, good selectivity, short analysis time and low cost. To further improve the detection sensitivity and selectivity, protein enzymes, functional nucleic acid enzymes etc. are often used due to the advantages of high catalytic efficiency and specificity. This review demonstrates the research progress of electrochemical sensors based on enzymatic amplification and analyses some existing problems of electrochemical sensors.

Resolve Mono-Electronic Process In The Voltammetric Behaviors Of Multi-Redox Bis-Coenzyme Q0, Hao Zhou, Yi-Tao Long

Journal of Electrochemistry

A widely held concept in electrochemistry is that truly elementary electron-transfer reactions always involve the exchange of one electron, therefore, an overall process involving a change of n electrons must involve n distinct electron-transfer steps. It is highly desirable to resolve multiple-step electron transfer reactions into each electron transfer step. The electrochemical behaviors of coenzyme Q₀ and methylene-bridged Bis-coenzyme Q₀ were investigated by cyclic voltammetry and square wave voltammetry in nonaqueous dichloromethane containing 0.15 mol·L^-1 Bu₄NClO₄ as the supporting electrolyte. The redox reaction of coenzyme Q₀ is well described as two chemically reversible …

Analysis Of Drug Interactions With Lipoproteins By High Performance Affinity Chromatography, Matthew R. Sobansky

Department of Chemistry: Dissertations, Theses, and Student Research

High density lipoprotein (HDL), low density lipoprotein (LDL), and very low density lipoprotein (VLDL) are lipoproteins previously shown to bind many basic and neutral hydrophobic drugs in serum. These interactions impact the distribution, delivery, metabolism, and excretion of drugs and are important in determining drug activity, pharmacokinetics, and toxicity in the human body. Information about drug-lipoprotein interactions and the strength of these interactions can be useful in determining the distribution of drugs following administration.

The research presented in this dissertation uses high performance affinity chromatography (HPAC) and packed columns to study binding of the drug propranolol to immobilized lipoproteins such …

Identification And The Significance Of Selective Proteins In Bile And Plasma Of Normal And Health-Compromised Chickens, Balamurugan Packialakshmi

Graduate Theses and Dissertations

During the last 50 years, animal breeding programs in commercial poultry have made significant progress in the bodyweight gain of broilers but led to several metabolic and skeletal disorders. Lameness associated with proximal femur known as femoral head separation (FHS) or femoral head necrosis (FHN) is one of the major metabolic disorders in poultry industry. In order to select for healthy chickens, markers that can distinguish between healthy and affected birds are required. Biomarkers from blood represent an ideal and rich source of markers which can be obtained using minimally invasive methods. The biomarkers were explored in an experimental model …

Probing The Unfolding And The Stability Of The Last Four Metal Binding Domains Of Wilson Disease Protein Using Circular Dichroism And Novel Spectroscopic Techniques, Ibtesam Yaseen Alja’Afreh

Dissertations

Wilson disease protein is a copper-transporting P_1B type ATPase. It has large N-terminal copper binding domain which is composed of six homologous sub-domains. Each of these six domains is ~72 residues and connected to one another by linking regions of various lengths. They all possess similar ferrodoxin fold, and metal-binding motif, MXCXXC.

The need of having six metal binding domains and the manner in which they are communicating with each other is not well understood. To better understand how the last four metal binding domains function, I pursued a detailed biophysical characterization of these domains. Using molecular biology I …

Simultaneous Determination Of Multiple Actinide Elements In A Variety Of Soils Utilizing A Standardized Sequential Extraction Protocol, Sherry Alina Faye

UNLV Theses, Dissertations, Professional Papers, and Capstones

To obtain a better understanding of the mobility of actinide element contaminants in the environment, the association of the contaminants with specific host phases of soils and sediments must be investigated. This investigation is most commonly conducted using sequential extraction techniques that employ the selective dissolution of soil phases with increasingly aggressive chemical treatment. Though several sequential extraction studies exist in literature, conclusions cannot be made by direct comparison of data due to the lack of uniformity in the protocols used. This work aims to continue development of a standard sequential extraction protocol and expanding its capabilities to include the …

Catechol Oxidation By Ozone And Hydroxyl Radicals At The Air-Water Interface, Elizabeth A. Pillar, Robert C. Camm, Marcelo I. Guzman

Chemistry Faculty Publications

Anthropogenic emissions of aromatic hydrocarbons promptly react with hydroxyl radicals undergoing oxidation to form phenols and polyphenols (e.g., catechol) typically identified in the complex mixture of humic-like substances (HULIS). Because further processing of polyphenols in secondary organic aerosols (SOA) can continue mediated by a mechanism of ozonolysis at interfaces, a better understanding about how these reactions proceed at the air–water interface is needed. This work shows how catechol, a molecular probe of the oxygenated aromatic hydrocarbons present in SOA, can contribute interfacial reactive species that enhance the production of HULIS under atmospheric conditions. Reactive semiquinone radicals are quickly produced upon …

Molecular Approaches To Chromatography Using Single Molecule Spectroscopy, Lydia Kisley

Faculty Scholarship

No abstract provided.

Electrochemical And Spectroscopic Studies Of Ethanol Oxidation On Nano-Cubic Pt Modified By Tin Adatoms, Lu Rao, Bin-Wei Zhang, Yan-Yan Li, Yan-Xia Jiang, Shi-Gang Sun

Journal of Electrochemistry

The nano-cubic Pt modified by tin (Sn) was synthesized and used to investigate the role of this adatom played in the ethanol oxidation. The onset potential of ethanol oxidation was significantly shifted negatively which can be forward about 300 mV when the coverage of Sn (θSn)was 0.9. The electrtochemical in situ FTIR result demonstrated that the amount of CO₂ increased first, and then decreased with θSn increased, and reached the maximun when θSn was 0.38. Furthermore, the formation of acetic acid could be observed at very low potential (-0.05 V) after modifying Sn adatom, and the amount of acetic …

Analysis Of Tyrosine And Its Halogenated Forms And Tripeptide –Metal Ion Clusters Using Mass Spectrometry, Bharathi Gannamani

All Capstone Projects

Chapter 1:

The aim of this research project was to measure the differences in proton affinities of tyrosine and its halogenated forms, 3-chlorotyrosine and 3-iodotyrosine. Tandem mass spectrometry was used here to measure the proton affinities. These amino acids were formed as protonated dimers with amino acids of known proton affinity and were introduced into the instrument through electrospray ionization (ESI). Based on the intensities of the protonated amino acids appeared in the mass spectrum when the dimer was isolated and fragmented, the proton affinities of the sample amino acids were calculated.

Chapter 2:

The research project was on mass …

The Kinetic Method: Determination Of Proton Affinity Of Proline By Cis And Trans Hydroxylation, Vinod Kanchi

All Capstone Projects

Unknown Proton affinity (PA) of the amino acids were determined by comparing them with known PA of the reference standards. Initially we mixed 2 amino acids together [unknown (PA) and known (PA)] and introduce into mass spectrometer using direct infusion. After injecting we observe the peaks. The protonated dimer peak of known PA and unknown PA samples were isolated and fragmented. Once they were fragmented protonated dimer will produce two peaks corresponding to amino acid with unknown PA and amino acids with known PA. Based on the ratio of these amino acids we determine the unknown PA of an amino …

Green Chemistry, Mary Lynn Koster

All Capstone Projects

In the academic year of 2014-2015, Governors State University will be accepting and enrolling freshman into the university. Therefore, the chemistry department will be offering general chemistry for the first time in its history. Now is the time to introduce the concept of Green Chemistry. Green Chemistry is not a new class but a philosophy that the department or at least the individual experiments within a lab course needs to looks at. There are 12 Principles of Green Chemistry:

1. Prevention
2. Atom Economy
3. Less Hazardous Chemical Syntheses
4. Designing Safer Chemicals
5. Safer Solvents and Auxiliaries
6. Design for Energy Efficiency
7. Use of Renewable …

Folate Targeted Agents For Diagnostic And Therapeutic Uses, Mekeda Carr

All Capstone Projects

Folic acid has been frequently exploited for target therapies geared toward overexpressed folate receptors on malignant cells. The folic acid/folate-receptor high affinity interaction can be used to not only target but image cancer cells. Folate-linked nanoparticles represent a potential new drug carrier for tumor cell-selective therapeutics. Folate targeting, nanoparticles in therapeutics, and cancer cell imaging will be outlined in this literature report.

New Strategies To Reveal Protein Candidates In Protein-Protein Interactome Study, Meng-Chieh Chen

Open Access Theses

Comprehensive protein-protein interaction network analysis can help reveal protein functions in a system-wide manner. A reliable knowledgebase of interaction networks is not only important for selecting the candidates for drug therapies, but also for evaluating the disease risk. In current interaction databases, 322579 interactions comprised of 56460 proteins have been reported (statistical analysis from APID: Agile Protein Interaction DataAnalyzer; http://bioinfow.dep.usal.es/apid/index.htm). The huge datasets are contributed mainly by yeast -two -hybrid (Y2H) screening and affinity-purification followed by mass spectrometry (AP-MS). High false positive rates and failing to cover certain interaction categories are the limitations of these two methods. Here, we developed …

Reverse-Phase Liquid Chromatography Of Small Molecules Using Silica Colloidal Crystals, Natalya Khanina

Open Access Theses

Capillaries packed with a silica colloidal crystal (SCC) of 470 nm nonporous particles have recently been shown to offer significant improvements in the peak width, resolution, and speed of protein analysis due to the reduction of the A and C term broadening contributions of the Van Deemter equation. While protein separations using this technology have shown vast improvements, small molecules remain largely unexplored. As the SCC allows for an approximately diffusion limited system, extremely high plate numbers are expected for small molecule separations. The research presented herein studies the feasibility of pressure-driven small molecule separation using SCCs and commercial instrumentation. …

Aircraft-Based Measurements For The Identification And Quantification Of Sources And Sinks In The Carbon Cycle, Dana R Caulton

Open Access Dissertations

Improved quantification of carbon-cycle sources and sinks is an important requirement for determining mitigation strategies and modeling future climate interactions. Analytically robust measurements require high-precision instrumentation and thoughtful experimental design to produce rigorous and reproducible results despite complex and quickly changing meteorological and environmental conditions. Here, an aircraft platform equipped with a high-precision cavity ring-down spectrometer for CO₂, CH₄ and H₂O quantification was used to acquire data from previously un-sampled sources. The aircraft mass-balance technique was used to quantify CH4 emissions from natural gas well pads in the drilling stage, which were 2-3 orders of …

Syntheses Of Aminyl Diradicals And Nitroxide Tetra- And Octaradicals, Arnon Olankitwanit

Department of Chemistry: Dissertations, Theses, and Student Research

This dissertation comprises of two main research projects: aminyl diradicals and calix[4]arene nitroxide tetra- and octaradicals. The design, multi-step synthesis and characterization, including NMR, EPR spectroscopy, magnetic measurements and X-ray crystallography of precursors and target compounds will be discussed.

Aminyl radicals, nitrogen-centered radicals, are typically short-lived and considered as reactive intermediates. Because of their unique magnetic properties, aminyls are attractive building blocks for high-spin di-and polyradicals. The challenge is in the design and synthesis of aminyls with increased stability. In this chapter, we have prepared triplet (S = 1) ground state aminyl diradicals, which are derivatives of aza-m …

Resonant Two-Photon Ionization Studies Of Non Covalent Interactions In Halo Aromatic Clusters And Spin-Orbit Coupling Modeling In Mono-Halocarbenes, Silver Nyambo

Dissertations (1934 -)

Non-covalent interactions in halobenzenes (PhX) (X=F, Cl, Br) and phenylamine (C₆ H₅ NH₂ ) have been studied here using resonance two-photon ionization (R2PI) spectroscopy combined with a linear TOF-mass spectrometer. Their interaction with polar molecules in form of ammonia (NH ₃ ) and trifluorohalomethanes (CF₃ X) has also been studied. DFT and TD-DFT calculations using M06-2X functionals were carried out on different cluster conformations to compliment experimental results. A general trend of broadness in homogenous dimers (PhX)₂ , has been attributed to mainly the presence of multiple cluster isomers and Frank-Condon activity in the low …

Electrochemical And Surface Enhanced Raman Spectroscopic Studies Of Benzimidazole On Nickel Electrode, Ping-Jie Wei, Ya-Xian Yuan, Min-Min Xu, Jian-Lin Yao, Ren-Ao Gu

Journal of Electrochemistry

By measuring cyclic voltammograms and polarization curves, the inhibition effects of benzimidazole (BMIH) concentration in acetonitrile system on a nickel electrode were investigated. It was found that the oxidation and the corrosion potentials shifted positively, and the oxidation current decreased with the increase in the concentration of BIMH. Potential dependent adsorption and film formation behavior of BMIH on the nickel electrode were investigated by in situ SERS spectroscopy. With the potential moving from negative direction to positive direction, the complexes made of BIMH and nickel were formed, preventing the nickel electrode from corrosion. In addition, the 0.001 mol·L^-1 of …

In-Situ Afm Force Curve Investigations On Layered Structures Of Au(111)-Ionic Liquid Interfaces And Temperature Dependence, Xiao Zhang, Yun-Xin Zhong, Jia-Wei Yan, Bing-Wei Mao

Journal of Electrochemistry

By utilizing in-situ AFM force curve measurements systematic investigations have been carried out on Au(111)-ionic liquid interface in BMIPF₆ and OMIPF₆ of imidazolium-based ionic liquids with different lengths of alkyl side chains. The temperature dependence of the number, thickness and stability of the layered structures of each system are studied by performing AFM force curve measurements at potentials far negative of the PZC. The layered structures at Au (111)/BMIPF₆ interface are composed of two charged interior layers and two neutral exterior layers at -1.0 V, while those at Au (111)/OMIPF₆ interface only one charged interior layer …

Investigation Of The Dynamics Of Photocarriers During Photoelectrochemical Water Splitting By Combination Of Photoelectrochemistry And Transient Absorption Spectroscopy, Wen-Hua Leng

Journal of Electrochemistry

Semiconductor photoelectrochemical hydrogen production is an important and promising technology for utilizing solar energy. The efficiency of hydrogen production depends on the efficiencies of separation and transport of photo-generated carriers. A deep understanding of the behavior of these processes has guiding significance for designing efficient solar hydrogen device. photoelectrochemical and transient absorption spectroscopy methods are powerful tool for studying the microscopic dynamics and mechanism of photocatalytic reaction. This review describes the part of the latest results of the author regarding the semiconductor photoelectrochemical hydrogen production obtained by these methods,and the problems and future research priorities in this field are proposed.

High Sensitive Detection Of Cd(Ii) And Pb(Ii) Based On Antimony-Film Covered Pencil Core Electrodes, Shan Chen, Zhao-Yan Zheng, Yi-Min Fang, Li-Qing Zheng, Jian-Jun Sun

Journal of Electrochemistry

In this paper, a pencil core was used as the substrate for an antimony-film electrode for simultaneous detection of Cd(II) and Pb(II) by square-wave anodic stripping voltammetry (SWASV). With the deposition time of 180 s, the low limit of detection (LOD) for the electrode was determined to be 0.075·g?L-1 for Cd(II), while 0.13·g·L-1 for Pb(II) with good reproducibility in low pH solutions (pH = 2). The results show a much lower LOD than that of bismuth-film pencil core electrode. Finally, this antimony-film electrode was successfully applied to determine Cd(II) and Pb(II) in tap water.

A Sensitive And Label-Free Electrochemical Aptasensor Based On Signal Amplification Of Carbon Nanotubes, Chun-Yan Deng, Hui-Min Fan, Juan Xiang, Yuan-Jian Li

Journal of Electrochemistry

A label-free electrochemical sensing electrode for highly sensitive detection of adenosine was constructed based on the signal amplification of carbon nanotubes (CNTs). The change in the interfacial feature of the modified electrode was characterized by electrochemical impedance spectroscopy. Using [Ru(NH₃)₆]³⁺ as the signaling moiety, adenosine with concentrations as low as 0.027 nmol·L^-1 can be selectively detected. Additionally, the fabrication of this present aptasensor was simple, time-saving and cost-effective. Compared with other reported aptasensors, the proposed aptasensor had advantages of excellent sensitivity, selectivity and simplicity, which plays a potential role in development of aptasensor.

Determining Kinetics For Simulated Sunlight-Exposed Oil Compounds, Dustin D. Kountz

LSU New Orleans Theses and Dissertations

Understanding of the fate of oil in the environment is of utmost importance; however, accurate, predictive models are still in very early stages. To aid in the development of these models, photodegradation of selected polycyclic aromatic hydrocarbons (PAHs) in an n-alkane hydrocarbon matrix was followed for individual PAHs and mixtures of PAHs similar to that found in the Deepwater Horizon spill. Tetracene in tetradecane photodegraded quickest of all observed PAHs, with a loss of 99% after only one hour of irradiation. Binary mixtures of PAHs showed different degradation amounts, including changes in PAH kinetics. These results suggest that the …

Synthesis And Applications Of Mutimodal Hybrid Albumin Nanoparticles For Chemotherapeutic Drug Delivery And Phototherml Therapy Platforms, Donna V. Peralta

LSU New Orleans Theses and Dissertations

Progress has been made in using human serum albumin nanoparticles (HSAPs) as carrier systems for targeted treatment of cancer. Human serum albumin (HSA), the most abundant human blood protein, can form HSAPs via a desolvation and crosslinking method, with the size of the HSAPs having crucial importance for drug loading and in vivo performance. Gold nanoparticles have also gained medicinal attention due to their ability to absorb near-infrared (NIR) light. These relatively non-toxic particles offer combinational therapy via imaging and photothermal therapy (PPTT) capabilities.

A desolvation and crosslinking approach was employed to encapsulate gold nanoparticles (AuNPs), hollow gold nanoshells (AuNSs), …

Mechanisms And Transients Involved In The Solar Conversion Of Petroleum Films In Aquatic Systems, Phoebe Z. Ray

LSU New Orleans Theses and Dissertations

The behavior of Deepwater Horizon crude oil and other sources of oil were investigated when exposed to sunlight in aquatic systems under environmentally relevant conditions. This research decoupled the abiotic and biotic weathering modifications of oil by focusing solely on the photochemical transformations of oil in aquatic systems. Photochemical rates and mechanisms were measured through the determination of reactive transients. Total hydroxyl radical formation was studied using high benzoic acid concentrations and varying exposure time. Titanium dioxide (TiO₂) nanomaterials were added to the system in an effort to determine if the photocatalyst would enhance oil photodegradation. Photochemical production …