Analytical Chemistry Commons^™

Development Of Dehydrogenase-Based Bioanode Using Poly(Phenosafranin)-Functionalized Swcnt Nanocomposites And Its Application To Ethanol Biosensor, S. Saleh Farhana, Okajima Takeyoshi, Lanqun Mao, Takeo Ohsaka

Journal of Electrochemistry

A New type of dehydrogenase-based amperometric ethanol biosensor was constructed using alcohol dehydrogenase (ADH) which was immobilized on the edge-plane pyrolytic graphite (EPPG) electrode modified with poly(phenosafranin)-functionalized single-walled carbon nanotube (PPS-SWCNT). The PPS-SWCNT modified EPPG electrode was prepared by electropolymerization of phenosafranin on the EPPG electrode which was previously coated with SWCNT. The performance of the ADH/PPS-SWCNT/EPPG electrode was evaluated using cyclic voltammetry and amperometry in the presence of ethanol. The fabricated ethanol biosensor provided a reasonable sensitivity of 2.0 μA cm–2 mM–1 and a low detection limit (36 μM) for the electrocatalytic oxidation of ethanol with a linear concentration …

Fabrication Of Ito Micro-Pore Electrochemical Sensor And The Detection Of Exocytosis, Hui Zhao, Ling Li, Pin-Gang He, Yu-Zhi Fang

Journal of Electrochemistry

Exocytosis is one of the major means for cells to transmit messages. Amperometric detection of exocytosis is an important method in studying communication between cells. In this study a new type of ITO micro-pore electrochemical sensor was fabricated by means of ITO and UV light lithographic mask and was used in the detection of exocytosis with promising results. Compared with the conventional method, the ITO micro-pore sensor can not only replace the carbon fiber electrode, but be combined with fluorescent or chemiluminescent methods in detecting the physiological phenomena of cells.

Study On The Electrochemical Behaviors Of Gc Electrode Modified With Carbon Nanotube-Polyelectrolytes And Its Application For Rutin Detection, Liang Hua, Xia-Qin Wu, Rong Wang

Journal of Electrochemistry

The electrochemical behaviors of rutin and ascorbic acid at single-wall carbon nanotube and polyelectrolytes (dimethyl-diallylammonium chloride, PDDA) film modified glassy carbon electrode was investigated. The cyclic voltammetric results showed that electron transfer of rutin at PDDA/SWCNTs/GC modified electrode is an adsorption-controlled process. The separation of oxidation peak potentials of rutin and ascorbic acid was more than 200 mV. The rutin concentration in the presence of AA were detected by differential pulse voltammetry (DPV). The experimental results indicated that the PDDA/SWCNTs/GC modified electrode can be used for the detection of rutin in the presence of high concentration of AA. The DPV …

Preparations And Characters For Acetamiprid Of Molecular Imprinted Polymer Electrochemical Sensors, Bin Liu, Yong-Xing Huang, Hui-Ting Lian, Hong-Mei Wu

Journal of Electrochemistry

A novel molecularly imprinted membranes electrochemical sensor with good memory capacity to acetamiprid was developed. Based on electrodeposition technique, chitosan was deposited onto the surface of gold electrode as a functional polymer matrix along with aimed molecules acetamiprid and glutaraldehyde as a crosslinking agent. Cationic probe Ru(NH₃)₆Cl₃ was employed to indirectly investigate the electrochemical characteristics as well as the imprinted effect of the sensors. The results showed that the sensors had a specific recognition to acetamiprid compared to the structural similarity midacloprid and other pesticide. There is more sensitive response to acetamiprid at imprinted sensors …

Determination Of Hexamethylene Bisacetamide, An Antineoplastic Compound, In Mouse And Human Plasma By Lc–Ms/Ms, Kerri M. Smith, Wannarasmi Ketchart, Xiang Zhou, Monica M. Montano, Yan Xu

Chemistry Faculty Publications

Hexamethylene bisacetamide (HMBA) is a polar compound which has recently been discovered to have antineoplastic activity by up-regulating the expression of an endogenous antiproliferative breast cancer protein, HEXIM1 (hexamethylene bisacetamide inducible protein 1) in vivo. HMBA has been shown in the past to induce terminal differentiation in multiple leukemia types at a concentration of 2–5 mM, but its phase I and II clinical trials were largely unsuccessful due to serious side effects (notably, thrombocytopenia) with dose escalation. In this work, a sensitive and simple LC–MS/MS method for direct determination of HMBA in mouse and human plasma is described. Plasma samples …

Single-Step Biofriendly Synthesis Of Surface Modifiable, Near-Spherical Gold Nanoparticles For Applications In Biological Detection And Catalysis, Vivek D. Badwaik

Masters Theses & Specialist Projects

There is an increased interest in understanding the toxicity and rational design of gold nanoparticles (GNPs) for biomedical applications in recent years. Such efforts warrant reliable, viable, and biofriendly synthetic methodology for GNPs with homogeneous sizes and shapes, particularly sizes above 30 nm, which is currently challenging. In the present study, an environmentally benign, biofriendly, singlestep/ single-phase synthetic method using dextrose as a reducing and capping agent in a buffered aqueous solution at moderate temperature is introduced. The resulting GNPs are near-spherical, stable, catalytically active, place exchangeable, and water-soluble within the size range of 10-120 nm. The added advantage of …

Synthesis, Extraction, Dissolution, And Voltammetry Of F-Species In A Room Temperature Ionic Liquid Solvent, Wendy Jacqueline Pemberton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Room temperature ionic liquids (RTILs) are salts that are liquids from as low as -96 °C to up to 100 °C. RTILs are of high interest in many fields of study because of their negligible vapor pressure, high electrochemical stability, high conductivity, and wide electrochemical windows. These diverse solvents have recently been used in organic synthesis, as extraction solvents, and as electrochemical solvents. It is as a direct result of the multifunctional capabilities of these RTIL solvents that they are examined in this work. The ability to probe the chemistry of lanthanides and actinides is based on the unique properties …

Equilibrium Speciation Of Select Lanthanides In The Presence Of Acidic Ligands In Homo- And Heterogeneous Solutions, Troy Robinson

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation explores lanthanide speciation in liquid solution systems related to separation schemes involving the acidic ligands: bis(2-ethylhexyl) phosphoric acid (HDEHP), lactate, and 8-hydroxyquinoline. Equilibrium speciation of neodymium (Nd³⁺ ), sodium (Na⁺ ), HDEHP, water, and lactate in the TALSPEAK liquid-liquid extraction system was explored under varied Nd³⁺ loading of HDEHP in the organic phase and through extraction from aqueous HCl and lactate media. System speciation was probed through vapor pressure osmometry, visible and Fourier Transform Infrared (FTIR) spectroscopy, ²² Na and ¹³ C labeled lactate radiotracer distribution measurements, Karl Fischer titrations, and equilibrium pH measurements. Distribution …

Miniature Mass Spectrometry: Rf Amplitude Control System Design, Matthew Allen Kirleis

Purdue Polytechnic Masters Theses

This thesis covers the methods used to construct and characterize a custom digital RF amplitude control system. Many types of mass spectrometers exist, but few have been miniaturized as much as the Mini instruments developed at Purdue University. The goal of this research was to improve upon an earlier amplitude control system consisting of analog circuits first implemented in the Mini 11.5 mass spectrometer developed at Purdue University.

A custom set of control and data acquisition electronics were developed for testing the digital and analog control systems in a Mini 11.5 mass spectrometer chassis. A MATLAB Simulink simulation was done …

Octaethyl-Nickel-Porphyrin Functionalized Silica For Fullerene Separation, Adriana Rodríguez^, Danisha M. Rivera, Luis Echegoyen*

COURI Symposium Abstracts, Summer 2011

No abstract provided.

Development And Applications Of Ionic Liquids And Near-Infrared Multispectral Imaging Techniques, Irena Mejac

Dissertations (1934 -)

In this work, we explore novel analytical applications of Ionic Liquids and Near-infrared multispectral imaging microscopy.

Ionic liquids (ILs) belong to a group of organic salts that are liquid at room temperature and can be, due to their unique chemical and physical properties, successfully used for a variety of applications. The main goal of this study was to explore the synergistic use of ILs in chemical separations. Specifically, chiral ILs were used as novel chiral selectors for Capillary Electrophoresis and as solvents for stationary phase in Gas Chromatography. As chiral selectors IL provides baseline-separation as well as enantiomeric separation of …

Comparative Analysis Of Peak-Detection Techniques For Comprehensive Two-Dimensional Chromatography, Indu Latha, Stephen E. Reichenbach, Qingping Tao

School of Computing: Faculty Publications

Comprehensive two-dimensional gas chromatography (GC×GC) is a powerful technology for separating complex samples. The typical goal of GC×GC peak detection is to aggregate data points of analyte peaks based on their retention times and intensities. Two techniques commonly used for two-dimensional peak detection are the two-step algorithm and the watershed algorithm. A recent study [4] compared the performance of the two-step and watershed algorithms for GC×GC data with retention-time shifts in the second-column separations.In that analysis,the peak retention-time shifts were corrected while applying the two-step algorithm but the watershed algorithm was applied without shift correction. The results indicated that the …

Nanoencapsulated Drug-Carrying System For Photodynamic Antimicrobial Chemotherapy (Pact), Gopala Krishna Murthy Kalapala

All Capstone Projects

The purpose of this study is to develop nanoparticulate drug-carrying systems that are capable of directly delivering photodynamic antimicrobial agents to treat patients with chronic wounds. Chronic wounds are considered as a pandemic health problem. Approximately 1% to 2% of the population in developing countries has experienced a chronic wound during their lifetime. In the United State States, according to the American Academy of Dermatology, the expense of treating chronic wounds constitutes over half of the total cost for all skin diseases, which exceeds $10 billion annually. For the last decade extensive basic science and clinical research in chronic wounds …

Micro Bca Analysis Of Proteins, Anusha Chennupati

All Capstone Projects

The main objective of this project was to develop and validate methods for detection and analysis of proteins using a newly introduced microdrop plate reader equipped with a 16 well microdrop reader (2 uL sample volume). We used commercially available BSA, egg albumin, trypsinogen, Pepsin, β-lactoblobulin and lysozyme as out test moieties. Protein drop size, time, BCA reagent quantity, was assessed at various levels using a microdrop micro-BCA protocol (Pierce Chemical Company) with the appropriate controls (PBS blank) the method validated using the appropriate statistical and method parameters (i.e %RSD, and regression analysis of the standard curves). The micro method …

Novel Ruthenium Complexes As Photodynamic Therapeutic Agents, Sareen Kumar Kushangari

All Capstone Projects

This project reviews the literature of novel ruthenium c complexes in photodynamic drug therapy. (Abstract by OPUS staff)

Analysis Of Anions In Water Samples From The Holy Land (Israel And Jordan) By Using Ion Chromatography, Ahalya Yalamanchili

All Capstone Projects

Ion chromatography is a form of liquid chromatography, which measures concentration of ionic species by separating them based on their interaction with resins. Ion chromatography is mainly useful for the separation and analysis of ions (cations or anions) in water. Analysis of anions in water is of greater importance because water is very important in daily life, especially in the Holy Land, where water is the very essence of life. If variety of chemicals, such as organic and inorganic salts enter into the water system, they make water toxic and poisonous to drink. In this project water samples from different …

Synthesis Of A Folate Receptor Mass Spectrometry Probe, Audrea Rhymes

All Capstone Projects

Drug delivery is one of the most important concepts for cancer patients because it is oftentimes very difficult or nearly impossible to exclusively target cancerous cells. In this study, the aim was to target receptors on cancerous cells, specifically the Folate Receptor (FR). This specific receptor was targeted because it has been proven to enhance intracellular delivery being that folic acid is an integral species in normal cell function and also that cancerous cells tend to exhibit an abnormally high concentration of Folic Acid on cell surfaces.

The application of dyes is a very common practice used to link folic …

Encapsulated Antibiotic Nanoparticles For Cranial Transplantation, Adusumilli Naga Anusha

All Capstone Projects

The purpose of this research is to develop a unique nanoparticulate system that is capable of delivering antibiotics in a locally applied and extended-release manner for patients receiving cranial replacement implants and bone grafting. This study involves three major components: first, encapsulate both hydrophobic antibiotics (chloramphenicol and rifampicine) and hydrophilic antibiotics (vancomycine and acyclovir) into nanoparticles. Second, incorporate antibiotic nanoparticles in a polymeric coating material (nitrocellulose plus 7.0% (w/v) polyvinylpyrrolidone) with a volatile carrier solvent (ethyl acetate or ethanol). Third, directly apply the resulting product from component 1 and 2 to polymethyl methacrylate (PMMA) cranial implants and hydroxylapatite (HA) bone …

Application Of Raman Spectroscopy To Lubricants, Lubricated Surfaces And Lubrication Phenomena, David W. Johnson

Chemistry Faculty Publications

Recent advances in lasers and detector technologies and the development of low-cost instruments and fiber-optic probes have brought about an explosion in the lubrication systems being studied by Raman spectroscopy. This article provides examples of the use of Raman spectroscopy in the study of lubrication phenomena, including the characterization of liquid lubricants, lubricant additives, and solid lubricants; the study of vapor-phase lubrication; and the use of coated nanoparticles as lubricants.

The Nature, Origin And Preservation Of Amide Organic Nitrogen In Organic Matter, Georgina Anne Mckee

Chemistry & Biochemistry Theses & Dissertations

Past studies have found much of nonliving sedimentary/aqueous nitrogen-containing organic matter (NCOM) is composed of amides, assumed to be peptides/proteins. Their lability calls into question their survival, and several hypotheses have been suggested to explain this. Using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and nuclear magnetic resonance (NMR) spectroscopy I investigated the molecular amide composition in sedimentary/aqueous systems while reassessing their preservation and formation routes.

Development of a suitable methodology is essential for successful NCOM study due to electrospray ionisation source requirements: sediment samples need to be rendered into solution. Based on NMR and FT-ICR-MS analysis, I determined …