Nanoscience and Nanotechnology Commons^™

The Application Of Graphene Films In Biosensing And Electrowetting, Xuebin Tan

Wayne State University Dissertations

In recent years, graphene has been found to possess extraordinary electronic, optical, mechanical and electrochemical properties. Graphene is optically transparent and mechanically flexible, and has high electron mobility and conductivity. In this thesis, we propose to investigate graphene's properties in the detection of biomolecules as well as the manipulation of biological samples. Graphene without defects has high charge carrier mobility and surface areas, which is ideal for biosensors. However, literature shows a lot of variations in the measurements using graphene biosensors. In addition, the surface functionalization of graphene in order to enhance the specificity has not been fully investigated yet. …

Near-Infrared Surface-Enhanced Fluorescence Using Silver Nanoparticles In Solution, Michael D. Furtaw

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Fluorescence spectroscopy is a widely used detection technology in many research and clinical assays. Further improvement to assay sensitivity may enable earlier diagnosis of disease, novel biomarker discovery, and ultimately, improved outcomes of clinical care along with reduction in costs. Near-infrared, surface-enhanced fluorescence (NIR-SEF) is a promising approach to improve assay sensitivity via simultaneous increase in signal with a reduction in background. This dissertation describes research conducted with the overall goal to determine the extent to which fluorescence in solution may be enhanced by altering specific variables involved in the formation of plasmonactive nanostructures of dye-labeled protein and silver nanoparticles …

Synthesis And Characterization Of Nucleic Acid-Functionalized Nanomaterials, Brianna S. Carroll, Jong Hyun Choi

The Summer Undergraduate Research Fellowship (SURF) Symposium

Motor proteins such as kinesin move along microtubules in order to transport cellular cargos throughout the cell by obtaining energy from RNA hydrolysis which allows the cell to complete the tasks needed to stay alive. In this work, we developed synthetic molecular motors using DNA enzymes (DNAzyme) and fluorescent nanomaterials which mimic the functions and structures of motor proteins. A DNAzyme-capped CdS nanoparticle and a RNA-functionalized single-walled carbon nanotube (SWCNT) were used as a walker and a track in the motor platform, respectively. As a walking mechanism, the DNAzyme cleaved the RNA substrates in the presence of metal cations. The …

Fluorescence Characterization Of Quantum Dots For Use As Biomarkers, Logan M. Grimes

Materials Engineering

Fluorescence profiles of quantum dots (QDs) were characterized to select the ideal QDs for encapsulation in phospholipids for use as biomarkers to selectively adhere to cancer cells. QDs were synthesized and extracted 0, 30, 60, and 90 seconds after precursor compounds were mixed. These extractions were isolated by extraction time. Portions from each vial were coated in a zinc sulfide shelling procedure, leaving at least half of the QD solution unshelled. These samples were characterized over four days to monitor fluctuations in fluorescence. This was done utilizing an Ocean Optics spectrometer in conjunction with Spectra Suite software. The central wavelength, …

Study Of Immobilizing Cadmium Selenide Quantum Dots In Selected Polymers For Application In Peroxyoxalate Chemiluminescence Flow Injection Analysis, Christopher S. Moore

Electronic Theses and Dissertations

Two batches of CdSe QDs with different sizes were synthesized for immobilizing in polyisoprene (PI), polymethylmethacrylate (PMMA), and low-density polyethylene (LDPE). The combinations of QDs and polymer substrates were evaluated for their analytical fit-for-use in applicable immunoassays. Hydrogen peroxide standards were injected into the flow injection analyzer (FIA) constructed to simulate enzyme-generated hydrogen peroxide reacting with bis-(2,4,6-trichlorophenyl) oxalate.

Linear correlations between hydrogen peroxide and chemilumenscent intensities yielded regression values greater than 0.9750 for hydrogen peroxide concentrations between 1.0 x 10^-4 M and 1.0 x 10^-1 M. The developed technique’s LOD was approximately 10 ppm. Variability of the prepared …

The Effect Of Network Transitions On Spontaneous Activity And Sycnhrony In Devloping Neural Networks, Jude P. J. Savarraj

Doctoral Dissertations

Connectivity patterns of developing neural circuits and the effects of its dynamics on network behavior, particularly the emergence of spontaneous activity and synchrony, are not clear. We attempt to quantify anatomical connectivity patterns of rat cortical cultures during different stages of development. By culturing the networks on dishes embedded with micro electrode arrays, we simultaneously record electrical activity from multiple regions of the developing network and monitor its electrical behavior, particularly its tendency to fire spontaneously and to synchronize under certain conditions. We investigate possible correlations between changes in the network connectivity patterns and spontaneous electrical activity and synchrony. Cocultures …

Intrinsic Mode Function Synchronization Measures For The Anticipation Of Seizures In Epilpsy, Daniel William Moller

Doctoral Dissertations

Epileptic seizures affect as many as 50 million people and often occur without warning or apparent provocation. We explore the applicability of noise-assisted Ensemble Empirical Mode Decomposition (EEMD) for patient-specific seizure anticipation synchronization measures as applied to the EEMD intrinsic mode function (IMF) output. Intracranial EEG data were obtained from pre-surgical monitoring at the Epilepsy Center of the University Hospital of Freiburg. Data from twenty patients were analyzed. For each recorded channel, non-overlapping time windows were submitted to the EEMD algorithm, producing twelve levels of IMFs. IMF synchronization measures (mean and maximum coherence, mean and maximum cross-correlation, correlation coefficient and …

Ultrasonication Assisted Layer-By-Layer Technology For The Preparation Of Multi-Functional Anticancer Drugs Paclitaxel And Lapatinib, Xingcai Zhang

Doctoral Dissertations

In this dissertation, ultrasonication assisted Layer-by-Layer (LbL) technology for the preparation of multifunctional poorly water-soluble anticancer drug nanoparticles, paclitaxel and lapatinib, has been developed. Many FDA approved drugs are very low soluble in water; therefore, it is very difficult to load and control their release and targeting efficiently, which greatly confines their application. The development of this method will pave the way for the development and application of those low soluble anticancer drugs.

In the first part of this dissertation, the first approach for powerful ultrasonication, the top-down approach (sonicating bulk drug crystals in polyelectrolyte solution), was successfully applied for …

Primary Pathways Of Intracellular Ca2+ Mobilization By Nanosecond Pulsed Electric Field, Iurii Semenov, Shu Xiao, Andrei G. Pakhomov

Bioelectrics Publications

Permeabilization of cell membranous structures by nanosecond pulsed electric field (nsPEF) triggers transient rise of cytosolic Ca²⁺ concentration ([Ca²⁺]_i), which determines multifarious downstream effects. By using fast ratiometric Ca²⁺ imaging with Fura-2, we quantified the external Ca²⁺ uptake, compared it with Ca²⁺ release from the endoplasmic reticulum (ER), and analyzed the interplay of these processes. We utilized CHO cells which lack voltage-gated Ca²⁺ channels, so that the nsPEF-induced [Ca²⁺]_i changes could be attributed primarily to electroporation. We found that a single 60-ns pulse caused fast [Ca2+]_i increase …

Systems Biology Of The Functional And Dysfunctional Endothelium, Jennifer Frueh, Nataly Maimari, Takayuki Homma, Sandra M. Bovens, Ryan M. Pedrigi, Leila Towhidi, Rob Krams

Department of Mechanical and Materials Engineering: Faculty Publications

This review provides an overview of the effect of blood flow on endothelial cell (EC) signalling pathways, applying microarray technologies to cultured cells, and in vivo studies of normal and atherosclerotic animals. It is found that in cultured ECs, 5–10% of genes are up- or down-regulated in response to fluid flow, whereas only 3–6% of genes are regulated by varying levels of fluid flow. Of all genes, 90%are regulated by the steady part of fluid flow and 10% by pulsatile components. The associated gene profiles show high variability from experiment to experiment depending on experimental conditions, and importantly, the bioinformatical …

Probe Immobilization Strategies And Device Optimization For Novel Transistor-Based Dna Sensors, Nicholas Michael Fahrenkopf

Legacy Theses & Dissertations (2009 - 2024)

The research presented herein exploits the terminal phosphate group on single stranded DNA molecules for direct immobilization to surfaces utilized in semiconductor device fabrication with the end goal of transistor based DNA sensors. As a demonstration of the feasibility of this immobilization strategy DNA immobilization to a variety of surfaces was evaluated for usefulness in biosensor applications. It was determined that DNA can be directly immobilized to a variety of semiconductor surfaces through the terminal phosphate group. Further, this immobilization allows for the hybridization of the immobilized DNA to complementary target in solution. The immobilization of DNA to hafnium dioxide …

Studies Of Functionalized Nanoparticles For Smart Self-Assembly And As Controlled Drug Delivery, Xiaochu Ding

Dissertations, Master's Theses and Master's Reports - Open

This dissertation is related to the studies of functionalized nanoparticles for self-assembly and as controlled drug delivery system. The whole topic is composed of two parts. In the first part, the research was conducted to design and synthesize a new type of ionic peptide-functionalized copolymer conjugates for self-assembly into nanoparticle fibers and 3D scaffolds with the ability of multi-drug loading and governing the release rate of each drug for tissue engineering. The self-assembly study confirmed that such peptide-functionalized amphiphilic copolymers underwent different self-assembly behavior. The bigger nanoparticles were more easily assembled into nanoparticle fibers and 3D scaffolds with larger pore …

A Dna Computer For Glioblastoma Multiforme Diagnosis And Drug Delivery, Sumaiya F. Hashmi

CMC Senior Theses

Glioblastoma multiforme (GBM) is a debilitating malignant brain tumor with expected patient survival of less than a year and limited responsiveness to most treatments, often requiring biopsy for diagnosis and invasive surgery for treatment. We propose a DNA computer system, consisting of input, computation, and output components, for diagnosis and treatment. The input component will detect the presence of three GBM biomarkers: vascular endothelial growth factor (VEGF), caveolin-1α (CAV), and B2 receptors. The computation component will include indicator segments for each of these genes, and ensure that output is only released if all the biomarkers are present. The output component …

Oscillator-Based Neuronal Modeling For Seizure Progression Investigation And Seizure Control Strategy, Wu Chen

Doctoral Dissertations

The coupled oscillator model has previously been used for the simulation of neuronal activities in in vitro rat hippocampal slice seizure data and the evaluation of seizure suppression algorithms. Each model unit can be described as either an oscillator which can generate action potential spike trains without inputs, or a threshold-based unit. With the change of only one parameter, each unit can either be an oscillator or a threshold-based spiking unit. This would eliminate the need for a new set of equations for each type of unit. Previous analysis has suggested that long kernel duration and imbalance of inhibitory feedback …

Ultrastable Synergistic Tetravalent Rna Nanoparticles For Targeting To Cancers, Farzin Haque, Dan Shu, Yi Shu, Luda S. Shlyakhtenko, Piotr G. Rychahou, B. Mark Evers, Peixuan Guo

Pharmaceutical Sciences Faculty Publications

One of the advantages of nanotechnology is the feasibility to construct therapeutic particles carrying multiple therapeutics with defined structure and stoichiometry. The field of RNA nanotechnology is emerging. However, controlled assembly of stable RNA nanoparticles with multiple functionalities which retain their original role is challenging due to refolding after fusion. Herein, we report the construction of thermodynamically stable X-shaped RNA nanoparticles to carry four therapeutic RNA motifs by self-assembly of reengineered small RNA fragments. We proved that each arm of the four helices in the X-motif can harbor one siRNA, ribozyme, or aptamer without affecting the folding of the central …

Cell Permeabilization And Inhibition Of Voltage-Gated Ca²+ And Na+ Channel Currents By Nanosecond Pulsed Electric Fields, Vasyl Nesin, Angela M. Bowman, Shu Xiao, Andrei G. Pakhomov

Bioelectrics Publications

Previous studies have found that nanosecond pulsed electric field (nsPEF) exposure causes long-term permeabilization of the cell plasma membrane. In this study, we utilized the whole-cell patch-clamp method to study the nsPEF effect on currents of voltage-gated (VG) Ca²⁺ and Na⁺ channels (I_Ca and I_Na) in cultured GH3 and NG108 cells. We found that a single 300 or 600 ns pulse at or above 1.5-2 kV/cm caused prolonged inhibition of I_Ca and I_Na. Concurrently, nsPEF increased a non-inactivating leak current (I_leak), presumably due to the formation of nanoelectropores or larger …

Virus Capsids As Nanoscale Delivery Vessels Of Photoactive Compounds For Site-Specific Photodynamic Therapy, Brian Alexander Cohen

Legacy Theses & Dissertations (2009 - 2024)

The research presented in this work details the use of a viral capsid as an addressable delivery vessel of photoactive compounds for use in photodynamic therapy. Photodynamic therapy is a treatment that involves the interaction of light with a photosensitizing molecule to create singlet oxygen, a reactive oxygen species. Overproduction of singlet oxygen in cells can cause oxidative damage leading to cytotoxicity and eventually cell death. Challenges with the current generation of FDA-approved photosensitizers for photodynamic therapy primarily stem from their lack of tissue specificity. This work describes the packaging of photoactive cationic porphyrins inside the MS2 bacteriophage capsid, followed …

Micropatterned Electrospun Nanofibrous Substrates As Scaffolds For Engineered Salivary Glands, David Alexander Soscia

Legacy Theses & Dissertations (2009 - 2024)

The salivary gland is a complex organ exhibiting a branching, 3-dimensional structure made up of acinar (saliva-producing), and ductal (saliva transporting and modifying) epithelial cells. The high surface area of the gland allows it to efficiently provide the mouth with saliva, maintaining oral cleanliness and comfort. Salivary gland hypofunction, a significant clinical problem often caused by the autoimmune disease Sjögren's syndrome or head and neck radiation for cancer patients, affects millions of Americans and is characterized by a loss of function of salivary gland acinar cells. Chronic xerostomia, or dry mouth, arises as a result of salivary gland hypofunction and …

Effect Of Extracellular Matrix (Ecm) Protein Micropatterns On The Behavior Of Human Neuroblastoma Cells, Ishwari Poudel

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Recent advances in patterning techniques and emerging surface microtechnologies have allowed cell micropatterning to control spatial location of the cells on a surface as well as cell shape, attachment area, and number of contacting neighbor cells. These parameters play important roles in cell cellular behaviors. Cell micropatterning has thus become one of the most important strategies for biomedical applications, such as, tissue engineering, diagnostic immunoassays, lab-on-chip devices, bio-sensing, etc., and cell biology studies as well. For neuronal cells, there have been attempts to distribute neuronal cells on specific patterns to control cell-to-cell interaction. However, there have been very limited understanding …

A Novel Telecommunications-Based Approach To Mathematical Modeling Of Hiv Infection, Aaron T. Sharp

Department of Computer Electronics and Engineering: Dissertations, Theses, and Student Research

It is well known that biological systems utilize communication in some form, one prolific example of this is the propagation of HIV (Human Immunodeficiency Virus) in the human body. By modeling HIV infection as a communication system, we hope to gain a unique insight into HIV and biological communication systems in general. Such a model would provide researchers a platform for experimenting and simulating various biological communication systems. We have previously developed a layered communication protocol for interpreting biological communication systems using telecommunications paradigms and will apply said model to HIV proliferation. We will also demonstrate the effectiveness of the …

Role Of Ammonia In The Activiation Of Methanol Dehydrogenase/Cytochrome C(L) Enzyme, Ancy Kunjumon

Doctoral Dissertations

Recent advancement in enzyme catalysis has opened ways to design efficient biocatalysts, bio-sensors and bio-fuel cells. An in-depth knowledge about the mechanism of the reaction taking place within the enzymes is of great importance to achieve these goals. In this dissertation, various computation methods are applied to investigate the mechanism behind enzyme catalysis in the presence of compounds called activators.

Methanol dehydrogenase (MDH) is a well-known bio-catalyst that can oxidize excess of methanol from the environment to formaldehyde. The enzyme works well within the bacterial environment, but under in vitro, it loses activity. Ammonia is used as an activator …

Passive Micromixers And Organic Electrochemical Transistors For Biosensor Applications, Senaka Krishna Kanakamedala

Doctoral Dissertations

Fluid handling at the microscale has greatly affected different fields such as biomedical, pharmaceutical, biochemical engineering and environmental monitoring due to its reduced reagent consumption, portability, high throughput, lower hardware cost and shorter analysis time compared to large devices. The challenges associated with mixing of fluids in microscale enabled us in designing, simulating, fabricating and characterizing various micromixers on silicon and flexible polyester substrates. The mixing efficiency was evaluated by injecting the fluids through the two inlets and collecting the sample at outlet. The images collected from the microscope were analyzed, and the absorbance of the color product at the …

Nanofabrication Of Halloysite-Pcl Composite Scaffolds And Functionalization Of Titanium For Tissue Regeneration, Shraddha Parshottambhai Patel

Doctoral Dissertations

Major medical needs may be achieved through regenerative medicine. Nanotechnology has triggered a research revolution in many important areas such as the biomedical sciences and bioengineering at the molecular level which has grown significantly due to the availability of new analytical applications and tools based on nanotechnology. Clinical conditions and diseases being targeted by nanotechnology research include burns, Alzheimer's and Parkinson's disease, implant failure, improved wound healing, birth defects, osteoporosis and congestive heart defects. Therapeutic use of growth factors and drugs to stimulate the production and/or function of endogenous cells represents a key area of regenerative medicine. The development of …

Structure And Optical Properties Of Self-Assembled Multicomponent Plasmonic Nanogels, Tao Cong, Satvik N. Wani, Peter Anthony Paynter, Radhakrishna Sureshkumar

Biomedical and Chemical Engineering - All Scholarship

Multicomponent plasmonic nanogels (PNGs) capable of broadband absorption of light in the 400-700 nm wavelength range were synthesized by the self-assembly of metal nanoparticles with wormlike surfactant micelles. Small angle x-ray scattering and rheological experiments suggest that the nanoparticles bridge micelle fragments to aid the formation a stable gel phase with exceptional color uniformity. Their optical absorbance could be robustly tuned by changing the nanoparticle type (Au/Ag), size, shape, and/or concentration. The PNGs have relatively low viscosity and are thermoreversible. Potential applications to the manufacturing of coatings and interfaces for solar energy harvesting and reconfigurable optical devices can be envisioned.

Surface Morphology Of Platelet Adhesion Influenced By Activators, Inhibitors And Shear Stress, Melanie Groan Watson

Doctoral Dissertations

Platelet activation involves multiple events, one of which is the generation and release of nitric oxide (NO), a platelet aggregation inhibitor. Platelets simultaneously send and receive various agents that promote a positive and negative feedback control system during hemostasis. Although the purpose of platelet-derived NO is not fully understood, NO is known to inhibit platelet recruitment. NO's relatively large diffusion coefficient allows it to diffuse more rapidly than platelet agonists. It may thus be able to inhibit recruitment of platelets near the periphery of a growing thrombus before agonists have substantially accumulated in those regions.

Results from two studies in …

Theory Of ‘Selectivity’ Of Label-Free Nanobiosensors – A Geometro-Physical Perspective, Pradeep R. Nair, Muhammad A. Alam

Birck and NCN Publications

Modern label-free biosensors are generally far more sensitive and require orders of magnitude less incubation time compared to their classical counterparts. However, a more important characteristic regarding the viability of this technology for applications in Genomics/Proteomics is defined by the ‘Selectivity’, i.e., the ability to concurrently and uniquely detect multiple target biomolecules in the presence of interfering species. Currently, there is no theory of Selectivity that allows optimization of competing factors and there are few experiments to probe this problem systematically. In this article, we use the elementary considerations of surface exclusion, diffusion limited transport, and void distribution function to …

Nanivid : A New Research Tool For Tissue Microenvironment Studies, Waseem Khan Raja

Legacy Theses & Dissertations (2009 - 2024)

Metastatic tumors are heterogeneous in nature and composed of subpopulations of cells having various metastatic potentials. The time progression of a tumor creates a unique microenvironment to improve the invasion capabilities and survivability of cancer cells in different microenvironments. In the early stages of intravasation, cancer cells establish communication with other cell types through a paracrine loop and covers long distances by sensing growth factor gradients through extracellular matrices. Cellular migration both in vitro and in vivo is a complex process and to understand their motility in depth, sophisticated techniques are required to document and record events in real time. …

Magnetic Sensors For Biodetection, Pranjali Vineet Sneha Deshpande

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of thesis is to design magnetic sensor for detection of nanoparticles. Recently integrating the standard laboratory techniques into integrated system on chip is growing attention. Recent development is to combine magnetic markers and magnetoresistive sensors together in magnetic chip. In this thesis two magnetoresistive sensors were studied and designed.

By applying magnetic fields, magnetic nanoparticles can be manipulated on-chip, which can be utilized to pull the molecules to specific binding sites or to test the binding strength and distinguish between specifically and non-specifically bound molecules

Magnetoresistive sensors are compatible with the semiconductor industry which provides electronic signal directly …

Gold Nanorod-Mediated Photothermolysis Induces Apoptosis Of Macrophages Via Damage Of Mitochondria, Ling Tong, Ji-Xin Cheng

Other Nanotechnology Publications

Aims: Induction of apoptosis or necrosis in activated macrophages by gold nanorod-mediated photothermolysis is demonstrated and the mechanisms underlying the processes are investigated. Materials & methods: Gold nanorods were functionalized with cysteine-octaarginine peptides (R8-NRs). Uptake of R8-NRs by activated macrophages was monitored by two-photon luminescence imaging. The laser irradiation conditions were controlled to induce apoptosis or necrosis to R8-NR-internalized macrophages. Mitochondrial damage and reactive oxygen species overproduction during photothermolysis was investigated by confocal fluorescence microscopy and transmission-electron microscopy. Results: Activated macrophages efficiently uptake R8-NRs both in vitro and in live animals. Laser irradiation of internalized nanorods with controlled power density …

Gold Nanorods As Contrast Agents For Biological Imaging: Optical Properties, Surface Conjugation And Photothermal Effects, Ling Tong, Qingshan Wei, Alexander Wei, Ji-Xin Cheng

Other Nanotechnology Publications

Gold nanorods (NRs) have plasmon-resonant absorption and scattering in the near-infrared (NIR) region, making them attractive probes for in vitro and in vivo imaging. In the cellular environment, NRs can provide scattering contrast for darkfield microscopy, or emit a strong two-photon luminescence due to plasmon-enhanced two-photon absorption. NRs have also been employed in biomedical imaging modalities such as optical coherence tomography or photoacoustic tomography. Careful control over surface chemistry enhances the capacity of NRs as biological imaging agents by enabling cell-specific targeting, and by increasing their dispersion stability and circulation lifetimes. NRs can also efficiently convert optical energy into heat, …