The “why” of any situation is one of the most important questions to ask. Inventors have ideas every day. Some ideas are the brilliant ideas that lead to a better tomorrow. To protect these ideas, inventors turn to patents, a governmental grant of the right to stop others, for a...
The development of simple, rapid, and sensitive methods for thiophenol detection is of great importance in various fields, including environmental monitoring and food quality. Here, we present a novel approach for the colorimetric detection of thiophenols using gold nanoparticles (AuNPs) as the sensing platform. AuNPs aggregate in the presence of...
American hop growers have historically dried hops in the range of 140-155°F/ 60-68°C using deep bed kilns (24 – 32 inches/ 60 – 81 cm), but over the last 10 years they have shifted to lower temperatures (125 -135 °F/ 52 – 57°C) for drying new American aroma cultivars. Reduced...
The concept of reducing laboratory operations into microfluidic devices has been an attractive area of research for several decades. Due to several advantages of porous-media microfluidic devices including low mass, portability, power-free fluid transport, and the ability to store dried reagents in the porous structures, these devices show great promise...
The detection of biomolecules is critical for clinical diagnostics but requires specialty labor and high cost. The use of microfluidic paper-based analytical devices (µPADs) for bioassays is simpler and cheaper but has low sensitivity. Improved immobilization of antibodies onto cellulose is demonstrated through surface functionalization with APTES and glutaraldehyde. The...
Radiation exposure to the brain can occur from a variety of events, including space missions, nuclear accidents, and clinical treatments. The effects of high dose radiation are well studied, but those of lower dosage are more elusive. Decline of memory and cognition is observed in patients exposed to low dose...
Electrodeposition is a versatile polymer deposition technique to create nano-microscale materials using an electrical field generated from a charged droplet of solution and a grounded collector. Electrospinning or electrospraying can occur during electrodeposition, leading to the creation of nanofibers or bead-like materials depending on the process parameters. Photopolymerization of the...
The general theme of this dissertation is the development of new analytical sensors to quantitatively study biological and environmental samples in aqueous and non-aqueous environments. A platinum ultramicroelectrode (UME) and a unique carbon-based pH microprobe were used to design a new SECM-based electrochemical bioassay. The Pt UME was used to...
Wine taste and mouthfeel are essential factors that determine consumer acceptance, consumer preference, and wine quality. The three taste descriptors, sweet, sour, and bitter, are well understood and routinely appearing in wine sensory. In contrast, information related to mouthfeel sensations is still relatively limited. Winemakers have worked hard to craft...
A simple Janus-type membrane-based wicking microfluidic device fabricated on a polycaprolactone-filled glass microfiber membrane enables separation and collection of blood plasma or serum from whole blood. This device bridges the wicking and cut-capillary-based solution transport mechanisms in a single membrane. The initial portion of the device is fabricated using selective...
High Performance Liquid Chromatography-Mass Spectrometry coupled with filtration, centrifugation, and other common sample preparation techniques offers a rapid and robust method for separating and quantifying propofol, a commonly used anesthetic, from human blood and its synthetic analogs. Method development is important for not only optimizing separation and quantification for a...
At This Point, an undergraduate-focused science podcast, works to expand the accessibility of science by exploring topics that, at this point, may seem too complex to understand. This thesis project describes the process of creating At This Point and demonstrates how the podcast fulfills the criteria of effective science communication....
The spalting fungus Scytalidium cuboideum secretes a red pigment that produces naphthoquinonic crystals that are a photonic material candidate. The molecule can pack together in different configurations resulting in amazingly different optical properties. I developed a procedure (slowly evaporating the solvent) to preferentially grow two of these configurations, which have...
Dental plaque is one of the well-characterized biofilms in the human body. Oral bacterial species play vital roles in maintaining healthy bacterial homeostasis as well as causing oral infections. Many of the oral diseases are caused by opportunistic pathogens, and therefore, the bacterial metabolic activities become important in dictating their...
There is significant interest in harnessing the biosynthetic capacities of photosynthetic diatom microalgae for the production of unique bioinspired nanomaterials. Specifically, this research focuses on understanding the photoluminescent properties of diatom biosilica and β-chitin nanofiber production in diatoms. Diatoms are single-celled microalgae that possess intricately patterned biosilica shells called, frustules....
Fungi from the genus Chlorociboria are known for their production of the blue-green quinonic pigment xylindein. Extracted xylindein has been the subject of investigations ranging from fabric dying to use a coloring agent in paint, and shows potential as an organic semiconductor in organic photovoltaics (OPVs) and other technologies. However,...
Electrospinning and electrospray are both nano-scale material fabrication techniques, based on related phenomena of electrically charged fluid spray from a droplet of liquid. Material is dissolved in liquid, then a spray is generated by applying a high voltage, creating an electric field, between the fluid dispensing capillary and a grounded...
Analytical techniques are utilized in a wide variety of applications. Traditionally, analytical measurements are achieved by trained personnel in a laboratory setting using expensive scientific instruments, which limits their applicability in resource-limited areas and point-of-care applications. Therefore, the concept of enabling these laboratory-based qualitative and quantitative assays in microfluidic device...
Historically, brewers have used dry-hopping (a cold extraction of nonvolatile and volatile chemicals from hops into fermenting or finished beer) to increase the microbial stability and shelf life of their beer. As hoppy beer styles have gained in popularity over the last decade (2007-2017), the objective of dry-hopping has turned...
The overall objective of this dissertation study was to develop and validate the performance of cellulose nanomaterials (CNs) incorporated fruit coatings for improving the storability of postharvest pears and bananas under various storage conditions. Four specific studies were conducted to fulfill the research objectives as stated below.
First, cellulose nanocrystal...
Protein adsorption on blood contacting medical devices usually causes fouling and failure, and may promote clotting and undesirable immune responses. Hydrophilic polymer coatings in a dense, pendent “brush” conformation can resist protein adsorption on the surface while increasing biocompatibility. Such coatings can also be used to immobilize a variety of...
The Micralyne microfluidic toolkit (μTK) was an instrument built by Micralyne in the early 2000’s. It was built for electrophoresis and has a sensitive laser-induced fluorescence detection system. The updates to the system were upgrading the control GUI from running in LabVIEW 5 (Windows XP, 2000) to LabVIEW 2012 (Windows...
The general theme of this dissertation is the application of novel carbon based micro sensors with the scanning electrochemical microscopy (SECM). SECM allows positioning of the probe without touching the substrate while mapping the chemical parameters in 3D space above the substrate. The main focus of the dissertation is the...
State-of-the-art, high-resolution mass spectrometry techniques for acquisition of metabolomic and lipidomic data coupled with advanced computational methods provide new opportunities for interpreting large and complex datasets and comprehending the underlying biological processes of diseases. Both metabolomics and lipidomics strive to obtain comprehensive analyses of small molecules, i.e., metabolites and lipids,...
Novel donor-typed ternary graphite intercalation compounds (GICs) are synthesized and characterized containing (1) pyrrolidinium cations with DMSO co-intercalates; (2) alkali metal cations with crown ether co-intercalates; and (3) alkali metal cations with polyethylene glycol co-intercalates. Structural and compositional data are obtained for the stable products. A new ether-amine co-intercalate exchange...
When hops are added to beer, varying degrees of hoppy aroma persist in the finished beer as a result of a number of factors. Dry-hopping is a technique whereby hops are added to beer post-fermentation to leverage the maximum aroma potential of the hop essential oils while minimizing bitterness contribution...
Three analytical methods for determination of aroma compounds in alcoholic beverages were developed and validated. These methods are sensitive and reliable that can be applied to analyze volatile phenols, stale aldehydes as well as some highly volatile aromas in alcoholic beverages. In the first study, an ethylene glycol (EG) polydimethylsiloxane...
Methane is a flammable gas that is the main component of natural gas. It is a highly potent greenhouse gas, and accounts for about 20% of greenhouse gas emissions. Methane is routinely flared in many industrial processes without harnessing any of its energy. The environmental impact and wasted energy potential...
Public attention and concern about per- and polyfluoroalkyl substances (PFASs) are increasing due to detection of PFASs in drinking water supplies, the environment, including remote locations, and wildlife and to the lowering of the federal health advisory levels of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in drinking water. Aqueous film-forming...
Commercial methodologies for producing fungal pigments are of worldwide interest due to the desire to move away from synthetic dyes. Chlorociboria species and Scytalidium species have been reported to produce sufficient yields of pigments for commercial production and have attracted special attention because of their use in spalted wood applications....
Chemical synthesis of oligonucleotides is a widely used tool in the field of biochemistry.
Several methods for gene synthesis have been introduced in the growing area of genomics.
In this paper, a novel method of constructing dsDNA is proposed. Short (28-mer) oligo fragments
from a library were assembled through successive...
Chemical synthesis of oligonucleotides is a widely used tool in the field of biochemistry.
Several methods for gene synthesis have been introduced in the growing area of genomics.
In this paper, a novel method of constructing dsDNA is proposed. Short (28-mer) oligo fragments
from a library were assembled through successive...
Full Text:
and an
Oligo Library
Sumate Pengpumkiat1, Myra Koesdjojo1, Erik R. Rowley2, Todd C. Mockler3, Vincent
This report details preliminary studies towards the development of a microfluidic
sensor that exploits ferromagnetic resonance, excited in magnetic bead labels, for signal
transduction. The device consists of a microwave circuit in which a slotline and a coplanar
waveguide are integrated with a biochemically activated sensor area. The magnetic beads...
Full Text:
.
Vincent T. Remcho received his BS in biochemistry in 1989 and his Ph.D. in chemistry
(with Prof. Harold
This report details preliminary studies towards the development of a microfluidic
sensor that exploits ferromagnetic resonance, excited in magnetic bead labels, for signal
transduction. The device consists of a microwave circuit in which a slotline and a coplanar
waveguide are integrated with a biochemically activated sensor area. The magnetic beads...
This report details preliminary studies towards the development of a microfluidic
sensor that exploits ferromagnetic resonance, excited in magnetic bead labels, for signal
transduction. The device consists of a microwave circuit in which a slotline and a coplanar
waveguide are integrated with a biochemically activated sensor area. The magnetic beads...
Full Text:
@eecs.oregonstate.edu,
Oregon State University
Remcho*, Vincent
Department of Chemistry, Vincent.Remcho
One post-transcriptional mechanism that regulates the progression of cancer and other diseases involves small 22-23 nucleotide sequences called microRNA (miR). Early detection of small changes in concentration of these biomarkers holds potential to diagnose diseases at their earliest stages. Use of current nucleic-acid based biosensors, like molecular beacons, for in...
Analytical chemistry is an area of chemistry primarily focused on the study and use of instruments for separation, identification, and quantification of an analyte of interest. Specifically, separation science within analytical chemistry often refers to the process of dividing mixtures into their small component parts based on differences in their...
Miniaturized and portable microfluidic analytical platforms have been widely explored in the broad field of chemical analysis. The concept of microfluidics offer a number of important advantages, including low reagent consumption, low-cost detection, high sample throughput, and shorter analysis time. Semiconductor nanocrystals or quantum dots have been extensively utilized in...
The development of nanomaterials and the potential enhancement of their chemical, mechanical, electrical, and optical properties have led to the investigation of methods for their synthesis at lower cost with enhanced performance for next generation devices. Along with the pursuit of new materials that exhibit properties of interest, industry requires...
A novel approach for the colorimetric detection of creatinine in a paper/polycaprolactone hybrid microfluidic device using alkaline3,5-dinitrobenzoate (DNB) is described. The reaction parameters of reagent concentration, alkalinity, and analysis time are optimized for fast reaction times and high color yield. Microfluidic devices incorporating this assay are designed and fabricated to...
The overall concept of reducing laboratory operations to a scale that fits on a single microfluidic chip has been an attractive area of research over the last several decades. Despite a surge in research, few commercial success stories have been written. Lab-on-a-chip technologies have the capability to be cost effective...
New graphite intercalation compounds (GICs) containing N,N-n-alkyl substituted pyrrolidinium cation intercalates (Py[subscript n.m], n, m = alkyl chain lengths) are obtained via cationic exchange from stage-1 donor-type GIC [Na(ethylenediamine)₁.₀]C₁₅. Powder X-ray diffraction and thermogravimetric analyses are used to determine the GIC structures and compositions. [Py₄.₈]C₄₇·0.71DMSO and [Py₈.₈]C₄₈ with intercalate monolayers...
European hazelnut (Corylus avellana L.) is an important crop Oregon's Willamette Valley, producing 99% of the hazelnuts grown in North America and brings over US $60 million dollars to the region annually. Hazelnuts are rich in fiber and vitamins, as well in demand by consumers due to their popularity as...
Chemical synthesis of oligonucleotides is a widely used tool in the field of biochemistry. Several methods for gene synthesis have been introduced in the growing area of genomics. In this paper, a novel method of constructing dsDNA is proposed. Short (28-mer) oligo fragments from a library were assembled through successive...
There has been a tremendous growth in interest in carbon nanodots (C-dots) in the past several years. As a nascent nanomaterial, C-dots have shown great promise in applications that benefit from their superior water dispersibility, low toxicity, non-blinking fluorescent output, chemical and biological compatibility, ease of functionalization and resistance to...
This dissertation describes the racemic and enantioselective synthesis cavicularin. Cavicularin is a macrocyclic bisbibenzyls family member natural product. It has been an attractive synthetic target due to its intriguing structure: the macrocyclic core imparts sufficient strain on the system to force one benzene rings to adopt a boat-shaped conformation, out...
Microalgae has been under careful consideration as a sustainable feedstock for renewable fuel recently due to its year round production with high energy yields per unit area, reduced need for arable land, water treatment benefits with nutrient cycling, and minimal competition with the food industry. Despite of all these advantages,...
Novel synthetic strategies are developed to prepare new intercalation compounds and nanocomposites with several layered hosts (NiPS₃, Na-montmorillonite, MoS₂ and MoO₃). In these products, alkali metals are ionic intercalates and linear polymers, dendrimers or amines act as co-intercalates. In addition to new synthetic approaches, new structures are identified and characterized....
The development and some applications of holographic optical tweezers (HOT) are presented. Our HOT system uses a spatial light modulator (SLM) to control the location and properties of the optical trap. We have developed a method for optimizing the diffraction efficiency of a SLM that can be applied in situ...
WLBU2 is an engineered cationic amphiphilic peptide that targets Gram-positive and Gram-negative bacteria, and envelopes endotoxin while avoiding other cell types. The exact mechanism of how WLBU2 targets, binds, and disrupts bacterial cell membranes is still not completely known. Thus, the overall goal of this investigation is to determine the...
Ethanol production from lignocellulosic feedstock has been under intense scrutiny as a transportation fuel due to its potential to address concerns of increasing energy consumption, limited fossil energy resources, climate changes due to greenhouse gas emissions from fossil fuels, and especially use of non-food biomaterials, which address the biggest limitation...
Low-dimensional electronic materials offer a platform to observe biological processes with unprecedented spatial and temporal resolution. Carbon nanotubes (CNTs) are the closest physical analog to an ideal 1D system and can be scaled and integrated into multiplexed electronic circuitry. The molecular structure of a CNT is also biocompatible, making them...
Advances in energy technologies and electronics have typically occurred through either heightened performance or cost reduction. This dissertation explores both routes through a series of fundamental material studies that may contribute to the enabling of next generation devices. Solution based syntheses and deposition of chemical products offer a low cost...
Novel donor-type graphite intercalation compounds (GICs) containing tetra-n-alkylammonium (TAA) cations have been synthesized by using both ion-exchange and electrochemical methods. Structural and compositional data of the resulting TAA-GICs are investigated by using powder X-ray diffraction (PXRD), one-dimensional electron density calculations, thermogravimetric and elemental analyses, and capillary zone electrophoresis (CZE). A...
Proteins are essential to all biological systems. Proteins participate in numerous cellular processes by interacting with other proteins, other metabolites and membranes in a dynamic environment. Studying the structural and conformational properties of proteins in the solution phase is necessary to understand their protein folding and interaction dynamics. This research...
Since their discovery in the 1990s, the great potential of carbon nanotubes (CNTs) has made them a focus of many research endeavors, including their application as components of biosensors. The inherent chemical "inertness" of CNTs makes their application to biosensing a challenge. It is necessary to "decorate" their surfaces to...
In this paper we present a novel fabrication technique that utilizes polycaprolactone (PCL) as bonding media due to its low melting temperature property. PCL is biodegradable polyester with a melting point of 60°C, and a glass transition temperature of -60°C [1-10]. It is employed as a rapid bonding technique in...
Cryopreservation of adherent cells may be advantageous for cell types that are difficult to
preserve in suspension or when it is necessary to preserve characteristics of the adherent cultured cells. Vitrification is a promising procedure for the preservation of adherent cells that prevents ice crystal formation and the resulting dissociation...
Carboxylic acids have played an important role in the field of actinide (An) and lanthanide (Ln) separations and the reprocessing of irradiated nuclear fuel. Recent bench-scale experiments have demonstrated that 3-carboxy-3-hydroxypentanedioic acid (citric acid) is a promising aqueous complexant that can effectively aid in the separation of transition metals from...
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants and are mostly products of the incomplete combustion of organic material. PAHs are often found in environmental samples as a complex mixture of isomers. In addition, the same sources that produce complex PAH mixtures also produce other poorly characterized mixtures of organic compounds,...
The challenges prompted by miniaturization of chromatographic systems have led scientists to explore new avenues in the synthesis of stationary phases. Packed capillary columns have found limited application in routine analysis due to a number of technical difficulties, most of which are attributable to the frits. New column designs insure...
For a number of reasons, miniaturization of chromatographic columns has been a general trend over the past three decades. Methods designed to enhance selectivity and efficiency can offer improved separation power and speed, expanding on the advantages of miniaturized columns. This dissertation describes novel approaches in this direction, focusing on...
It is the responsibility of humans, as environmental stewards, to monitor our impact on the environment so that efforts can be made to remediate the effects of our actions and change behaviors. To better understand our environmental footprint, sensitive and simple analytical methods are needed to quantify the contaminants that...
Fluorinated alkyl substances, which can be persistent, toxic, and
bioaccumulative, have been quantitated in many densely populated and
remote regions, including in air, surface waters, groundwater, and biota;
however, little is known about their transport or behavior in the environment.
Wastewater effluent is one of the principal routes for introducing...
The materials Fe₂(Si,Ge)(S,Se)₄, Cu₃PS[subscript 4-x]Se[subscript x] (0 ≤ x ≤ 4), and Cu₃PxAs[subscript 1-x]S₄ (0 ≤ x ≤ 1) have been synthesized and studied as new earth-abundant absorbers for single and multijunction photovoltaic cells as well as solar fuel generation. The synthesis, single-crystal growth, and optical and electrical properties of...
A system to reversibly extract Pb²⁺ ions from aqueous solutions using spiropyran functionalized nanofibers was proposed. Spiropyrans are photochromic compounds which undergo a conformational change that alters their physical properties and makes Pb²⁺ binding possible upon irradiation with UV light (365 nm). Irradiation with green light (525 nm) reverses this...
Due to a number of disadvantages associated with the use of antibodies as
affinity stationary phases, researchers have recently began to explore the use of RNA
and DNA aptamers for use as affinity stationary phases. These molecules have been
shown to be a viable choice for applications in many methods...
Over the last decade, the miniaturization of analytical systems has become an increasingly important and interesting research area. Miniaturized systems offer many advantages, including reduced reagent and sample consumption, shorter analysis times, portability and disposability. This dissertation describes novel approaches in this direction, focusing on two areas: the miniaturization of...
New methods, sensors, and devices based on redox indicators were developed to
monitor redox conditions in anoxic and anaerobic laboratory systems and the subsurface
environment. The primary application was monitoring redox conditions
during the dechlorination of tetrachioroethene (PCE) to ethene (ETH) in packed
columns and microcosm bottles containing an enriched...
Microchannel process technology (MPT) offers several advantages to the field of nanomanufacturing: 1) improved process control over very short time intervals owing to shorter diffusional distances; and 2) reduced reactor size due to high surface area to volume ratios and enhanced heat and mass transfer. The objective of this thesis...
Frozen Marion (Rubus sp. hyb) and Evergreen blackberries (Rubus laciniatus) (whole berries, berries without seeds, and seeds alone) were acetone/ chloroform extracted. Phenolics were isolated using C₁₈ cartridges and polyamide resins, then characterized and measured by reversed-phase HPLC/diode array spectral techniques. The Polyamide isolated fractions of Marion berries contained four...
The distribution of anthocyanin pigments and polyphenolics of sweet (Prunus avium) and sour cherries (Prunus cerasus) were determined by Ultraviolet- Visible (UV-Visible) spectrophotometry and High Performance Liquid Chromatography with photodiode array detector (HPLC-DAD). Their antioxidant properties were determined by Oxygen Radical Absorbance Capacity (ORAC) and Ferric Reducing Antioxidant Power (FRAP)....
The influence of cultivar and maturity on polyphenolic composition and
antioxidant activity was investigated by UV-Visible spectrophotometry and
analytical high performance liquid chromatography (HPLC) in commercially
important blackberry cultivars and selections. The anthocyanin pigments changed
tremendously with ripening. Total anthocyanins increased from 74.7-317 mg/100g
fw from underripe to over ripe...
The objective of this study was to identify aroma volatiles in sweet whey powder. Volatiles were isolated by solvent extraction and solvent assisted flavor evaporation. Fractionation was followed to separate acidic volatiles from nonacidic volatiles. Gas chromatography/olfactometry and gas chromatography-mass spectrometry were used for the identification ofaroma compounds. Osme methodology...
The intriguing size- and shape dependent properties of nanoparticles have garnered recent attention in many science and engineering areas. When the particle size is in the nanometer size range, the material exhibits very different properties such as surface plasmon resonance (of gold nanoparticles) and superparamagnetism (of iron oxide nanoparticles). The...