Download or read book Optical Studies of Oligonucleotide Interactions and Gold Nanoparticles Toward Improved DNA Detection at Surfaces written by Yang Gao and published by . This book was released on 2008 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: DNA-based optical biosensors are based on employing tailored surface-bound oligonucleotides probes to detect complementary target strands via hybridization. As interest grows in the application of these biosensors, there is a need for a better understanding of how the surface environment and the oligonucleotide structures affect biosensor performance. The fundamental studies presented in this thesis are a step towards understanding the above effects. By studying the kinetics of oligonucleotide hybridization in solution and on surface, we were able to evaluate of surface effects on DNA duplex formation (hybridization). We found that surface suppresses the rates of duplex formation by 20-40 fold compared to bulk solution, which we attributed to entropic effects. Additionally, we investigated the effect of single-stranded DNA secondary structure on hybridization. For the first time we established a linear trend for a decrease in the association rate constants with an increase in the free energies of the folded single strands for 25-mer oligonucleotides. All of the surface work presented in this study was performed using surface plasmon resonance (SPR) spectroscopy, a label-free technique. The solution measurements were also obtained using unlabeled oligonucleotides by UV spectroscopy with a home-built syringe injection setup. Label-free optical techniques are relatively insensitive. One approach to enhance signals in DNA biosensors is to use gold (Au) nanoparticles (AuNP) as labels at the planar substrates. However, knowledge of the optical properties of the nanoparticles is required to quantify the kinetic and thermodynamic binding of the target molecules. We investigated the dielectric constants for AuNP as a function of wavelength, inter-particle and particle-substrate distance using surface plasmon resonance imaging (SPRI). Preliminary results showed that for 10-run AuNP the dielectric constants agree with the theoretical prediction at the wavelengths studied. We estimate that, by employing AuNP, our SPR detection sensitivity is increased by 300 fold compared to a label free measurement. As expected, the dielectric constants of the nanoparticles are independent of the particle-substrate distance when the distance is greater than the diameter of the nanoparticles. Feasibility to investigate the distance effects at shorter (

Download or read book Nanoparticle Probes for the Study of Biomolecular Interactions written by Fiona McKenzie and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a growing requirement to be able to detect interactions between biological molecules to develop our understanding of disease expression and progression and for improvement of patient diagnosis in medical applications. One of the most effective ways this can be achieved is to label biomolecules with optically active reporters. To date this has been performed using fluorescent dyes; however there has been recent interest in the use of noble metal nanoparticles due to their large extinction coefficients and near-field properties. This research details the preparation of oligonucleotide functionalised gold and silver nanoparticles for the detection of single and double stranded DNA sequences. The oligonucleotides are modified to incorporate locked nucleic acid (LNA) ribose sugars, affording highly advantageous affinity and selectivity properties. Hybridisation of the probes with the target sequence was monitored colorimetrically and by extinction spectroscopy. Double stranded DNA was targeted through formation of a triple-stranded DNA structure via Hoogsteen hydrogen bonding. The nanoparticle probes were further utilised for detection by surface enhanced resonance Raman scattering (SERRS). This method of detection enables multiple DNA sequences to be detected simultaneously due to the molecularly specific and narrow emission spectral profiles obtained. As such, the multiplexing capabilities of this detection method were investigated, indicating that as many as five dye-labelled oligonucleotides could be identified within one spectrum without application of chemometric techniques. A novel method for the incorporation of a SERRS label into oligonucleotide nanoparticle probes was developed which was found to be compatible with a number of commercially available dyes, increasing their potential in multiplexed analysis. Biomolecular SERRS detection was also extended towards cellular analysis using antibody functionalised gold nanoparticles for targeting cell surface receptors. Conjugation was achieved using a novel linker incorporating a chromophore excitable by near-infrared radiation. Using SERRS line mapping, numerous cells could be analysed and were shown to exhibit discrete areas of receptor expression which was quantified by inspection of SERRS intensity and the number of active pixels in the SERRS map.

Download or read book Understanding Tuberculosis written by Pere-Joan Cardona and published by BoD – Books on Demand. This book was released on 2012-02-15 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mycobacterium tuberculosis is a disease that is transmitted through aerosol. This is the reason why it is estimated that a third of humankind is already infected by Mycobacterium tuberculosis. The vast majority of the infected do not know about their status. Mycobacterium tuberculosis is a silent pathogen, causing no symptomatology at all during the infection. In addition, infected people cannot cause further infections. Unfortunately, an estimated 10 per cent of the infected population has the probability to develop the disease, making it very difficult to eradicate. Once in this stage, the bacilli can be transmitted to other persons and the development of clinical symptoms is very progressive. Therefore the diagnosis, especially the discrimination between infection and disease, is a real challenge. In this book, we present the experience of worldwide specialists on the diagnosis, along with its lights and shadows.

Download or read book Optical Investigation of Oligonucleotide nanoparticle Conjugates with Applications to Genetic Analysis written by Deirdre Margaret Murphy and published by . This book was released on 2004 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates the optical properties and applications of oligonucleotide-nanoparticle conjugates. One of the major themes focused on in this work is in the use of conjugates to detect mutations in DNA sequences. To this end, and in order to gain an insight into the reactivity and stability of DNA sequences, a thermodynamic study of three-strand oligonucleotide complexes is first employed to assess the effect of base stacking and base pair mismatch on the relative thermodynamic stabilities of oligonucleotide duplexes. Methods for selective optical detection and discrimination of CF-related genetic mutations in model oligonucleotide systems using oligonucleotide-nanoparticle conjugates are then presented. Three strand oligonucleotide complexes are employed, wherein two probe oligonucleotide-gold nanoparticle conjugates are linked together by a third target oligonucleotide strand bearing the CF-related mutation(s). The temperature dependence of the optical absorption properties of the complexes is monitored, in solution and on TLC plates, and melting behaviours are compared. Using this approach, fully complementary sequences are successfully distinguished from mismatched sequences, with single base mismatch resolution, for F 508, M470V, R74W, R75Q and V232D mutations. For more sensitive monitoring of solution based oligonucleotide-nanoparticle conjugate melting a novel miniaturised optical monitoring system is then developed. This device is used to detect CF-related mutations and to achieve excellent single nucleotide polymorphism discrimination at sub-picomole level target detection. Gold nanoparticle labels are also employed to probe the temperature dependent optical properties of DNA triple helices. By using oligonucleotide-nanoparticle conjugates to characterize triplex denaturation, for the first time triplex-to-duplex melting transitions are sensitively monitored, with minimal signal interference from duplex-to-single strand melting, for both parallel and antiparallel triple helices. Finally, the conjugation of nanoparticles to peptide nucleic acid and PNA-DNA chimeras is also investigated. The hybridisation and melting properties of complexes formed from chimera-nanoparticle conjugates and oligonucleotide-nanoparticle conjugates are described for first time and mismatch discrimination is shown to be more pronounced than with unmodified oligonucleotides.

Download or read book Nanobiosensors written by Alexandru Grumezescu and published by Academic Press. This book was released on 2016-09-28 with total page 928 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanobiosensors: Nanotechnology in the Agri-Food Industry, Volume 8, provides the latest information on the increasing demand for robust, rapid, inexpensive, and safe alternative technologies that monitor, test, and detect harmful or potentially dangerous foods. Due to their high sensitivity and selectivity, nanobiosensors have attracted attention for their use in monitoring not only biological contaminants in food, but also potential chemical and physical hazards. This book offers a broad overview regarding the current progress made in the field of nanosensors, including cutting-edge technological progress and the impact of these devices on the food industry. Special attention is given to the detection of microbial contaminants and harmful metabolotes, such as toxins and hormones, which have a great impact on both humans and animal health and feed. Includes the most up-to-date information on nanoparticles based biosensors and quantum dots for biological detection Provides application methods and techniques for research analysis for bacteriological detection and food testing Presents studies using analytical tools to improve food safety and quality analysis

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 1006 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanoparticles in Biology and Medicine written by Mikhail Soloviev and published by Methods in Molecular Biology. This book was released on 2012-07-13 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt: The modern fascination with micro- and nano-sized materials can actually be traced back further to the 1960s and ‘70s when the first few reported attempts were made to use nanoparticles for controlled drug delivery. In Nanoparticles in Biology and Medicine: Methods and Protocols, experts in the field present a wide range of methods for synthesis, surface modification, characterization, and application of nano-sized materials (nanoparticles) in life science and medical fields, mostly for drug delivery. The methods presented cover all stages of nanoparticle manufacturing, modification, analysis, and applications. Written in the highly successful Methods in Molecular BiologyTM series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Comprehensive and cutting-edge, Nanoparticles in Biology and Medicine: Methods and Protocols will help the beginner become familiar with this fascinating field and will provide scientists at all levels of expertise with easy-to-follow practical advice needed to make, modify, and analyze nanoparticles of their choice and to use them in a wide range of biomedical and pharmaceutical applications, including functional protein studies, drug delivery, immunochemistry, imaging, and many others.

Download or read book Molecular Engineering of Gold Nanorod Surfaces Towards Improved Physical Properties and Understanding Nanoparticle cell Interactions written by Alaaldin M. Alkilany and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Gold nanorods have unique optical properties and various promising applications. Wet chemical synthesis of gold nanorods requires the use of cetyl trimethylammonium bromide (CTAB) as shape-directing surfactant, which form a bilayer on the surfaces of gold nanorods. CTAB bilayer stabilizes the nanorods against aggregation and has the ability to sequester organic molecules from aqueous bulk. CTAB molecules in the bilayer are held via weak hydrophobic forces and thus tend to desorb resulting in nanorods aggregation and toxicity to cultured cells. Herein, three surface-engineering approaches to enhance the colloidal physical stability and biocompatibility of gold nanorods have been examined: 1) electrostatic approach via overcoating with polyelectrolytes; 2) covalent approach via surfactant polymerization; 3) and hydrophobic approach via cholesterol insertion into the bilayer. Layer-by-layer coating has been used to overcoat CTAB-capped nanorods with both negatively and positively charged polyelectrolytes. Compared to CTAB-capped nanorods, polyelectrolyte-coated gold nanorods showed improved stability against aggregation in culture medium and enhanced biocompatibility to cultured cells. The toxicity of CTAB-capped gold nanorod solutions was assigned quantitatively to free CTAB molecules, where gold nanorods themselves were found not toxic. Similar biocompatibility profiles for both cationic and anionic coated-gold nanorods were observed due to spontaneous protein adsorption. In growth media, all examined nanorods were covered with protein corona and thus bear similar negative effective surface charge explaining their similar toxicity profiles. ! """! ! Our covalent approach to stabilize the surfactant bilayer on the surface of gold nanorods relies on synthesizing a polymerizable version of the CTAB, which we have used to prepare gold nanoparticles (both spheres and rods). Surfactant polymerization on the surface of gold nanoparticles was found to retard surfactant desorption and thus enhance both stability against aggregation and biocombatibility of these nanomaterials. The hydrophobic approach to stabilize the CTAB bilayer on gold nanorods relies on using a bilayer-condensing agent such as cholesterol to increase the total hydrophobic interactions. Cholesterol is known to consist of up to 50% of mammalian cell membrane0́9s total lipids, and thus have important effect on their stability and physical properties. Using cholesterol-rich growth medium, we have prepared gold nanorods with excellent size and shape distribution. The prepared gold nanorods in the presence of cholesterol have a significantly higher surface charge and exhibit superior stability against aggregation compared to the nanorods prepared without cholesterol. In addition to the enhanced aqueous stability and biocompatibility, stabilization the CTAB bilayer on the surface of gold nanorods have allowed for suspension gold nanorods in organic solvents without aggregation. Polyelectrolyte-coated gold nanorods showed remarkable stability in polar organic solvents against aggregation as compared to CTAB-capped nanorods. The suspendability of coated-gold nanorods in polar organic solvents facilitates the incorporation of these nanomaterials into hydrophobic polymers and thus fabrication of thin films that contain uniform gold nanorod dispersions (nanocomposites).

Download or read book Optical Antennas written by Mario Agio and published by Cambridge University Press. This book was released on 2013-01-03 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: This consistent and systematic review of recent advances in optical antenna theory and practice brings together leading experts in the fields of electrical engineering, nano-optics and nano-photonics, physical chemistry and nanofabrication. Fundamental concepts and functionalities relevant to optical antennas are explained, together with key principles for optical antenna modelling, design and characterisation. Recognising the tremendous potential of this technology, practical applications are also outlined. Presenting a clear translation of the concepts of radio antenna design, near-field optics and field-enhanced spectroscopy into optical antennas, this interdisciplinary book is an indispensable resource for researchers and graduate students in engineering, optics and photonics, physics and chemistry.

Download or read book Nanomaterials for Biosensors written by Bansi D. Malhotra and published by William Andrew. This book was released on 2017-10-26 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanomaterials for Biosensors: Fundamentals and Applications provides a detailed summary of the main nanomaterials used in biosensing and their application. It covers recent developments in nanomaterials for the fabrication of biosensor devices for healthcare diagnostics, food freshness and bioprocessing. The various processes used for synthesis and characterization of nanostructured materials are examined, along with the design and fabrication of bioelectronic devices using nanostructured materials as building blocks. Users will find the fundamentals of the main nanomaterials used in biosensing, helping them visualize a systematic and coherent picture of how nanomaterials are used in biosensors. The book also addresses the role of bio-conjugation of nanomaterials in the construction of nano-biointerfaces for application in biosensors. Such applications, including metal nanoparticles, metal oxide nanoparticles, nanocomposites, carbon nanotubes, conducting polymers and plasmonic nanostructures in biosensing are discussed relative to each nanomaterial concerned. Finally, recent advancements in protein functionalized nanomaterials for cancer diagnostics and bio-imaging are also included. Provides a detailed study on how nanomaterials are used to enhance sensing capabilities in biosensors Explains the properties, characterization methods and preparation techniques of the nanomaterials used in biosensing Arranged in a material-by-material way, making it clear how each nanomaterial should be used

Download or read book Bioconjugate Techniques written by Greg T. Hermanson and published by Academic Press. This book was released on 2010-07-26 with total page 1233 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioconjugate Techniques, 2nd Edition, is the essential guide to the modification and cross linking of biomolecules for use in research, diagnostics, and therapeutics. It provides highly detailed information on the chemistry, reagent systems, and practical applications for creating labeled or conjugate molecules. It also describes dozens of reactions with details on hundreds of commercially available reagents and the use of these reagents for modifying or cross linking peptides and proteins, sugars and polysaccharides, nucleic acids and oligonucleotides, lipids, and synthetic polymers. A one-stop source for proven methods and protocols for synthesizing bioconjugates in the lab Step-by-step presentation makes the book an ideal source for researchers who are less familiar with the synthesis of bioconjugates More than 600 figures that visually describe the complex reactions associated with the synthesis of bioconjugates Includes entirely new chapters on the latest areas in the field of bioconjugation as follows: Microparticles and nanoparticlesSilane coupling agentsDendrimers and dendronsChemoselective ligationQuantum dotsLanthanide chelatesCyanine dyesDiscrete PEG compoundsBuckyballs,fullerenes, and carbon nanotubesMass tags and isotope tagsBioconjugation in the study of protein interactions

Download or read book Spherical Nucleic Acids written by Chad A. Mirkin and published by CRC Press. This book was released on 2021-10-14 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spherical nucleic acids (SNAs) comprise a nanoparticle core, and a densely packed and highly oriented nucleic acid shell. They have novel structure-dependent properties that differ from those of linear nucleic acids and that makes them useful in chemistry, biology, the life sciences, medicine, materials science, and engineering. This book is a reprint volume that compiles 101 key papers that have been published by the Mirkin Group at Northwestern University, USA, and their collaborators over the past more than two decades. Volume 1 provides an overview and a historical framework of SNAs and discusses their enabling features, which set them apart from all other forms of matter. Volume 2 covers the general design rules for colloidal crystal engineering with DNA, spanning the building blocks and DNA- and RNA-based "programmable bonds" that can be utilized in preparing such structures. Volume 3 continues the discussion of colloidal crystallization processes and routes to hierarchical assembly, featuring dynamic nanoparticle superlattices and lattices prepared on surfaces or via templating strategies, and explores what one can uniquely learn from and do with colloidal crystals prepared from nucleic acid–functionalized nanomaterials in optics, plasmonics, and catalysis. Volume 4 covers the role of SNAs in biomedicine, especially as diagnostic probes both inside and outside of cells, and treatments based on gene regulation and immunotherapy.

Download or read book Nanotechnology Science and Computation written by Junghuei Chen and published by Springer Science & Business Media. This book was released on 2006-06-29 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoscale science and computing is becoming a major research area as today's scientists try to understand the processes of natural and biomolecular computing. The field is concerned with the architectures and design of molecular self-assembly, nanostructures and molecular devices, and with understanding and exploiting the computational processes of biomolecules in nature. This book offers a unique and authoritative perspective on current research in nanoscale science, engineering and computing. Leading researchers cover the topics of DNA self-assembly in two-dimensional arrays and three-dimensional structures, molecular motors, DNA word design, molecular electronics, gene assembly, surface layer protein assembly, and membrane computing. The book is suitable for academic and industrial scientists and engineers working in nanoscale science, in particular researchers engaged with the idea of computing at a molecular level.

Download or read book Electrochemical DNA Biosensors written by Mehmet Sengun Ozsoz and published by CRC Press. This book was released on 2012-04-23 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the basic electrochemical applications of DNA in various areas, from basic principles to the most recent discoveries. The book comprises theoretical and experimental analysis of various properties of nucleic acids, research methods, and some promising applications. The topics discussed in the book include electrochemical detection of DNA hybridization based on latex/gold nanoparticle and nanotubes; nanomaterial-based electrochemical DNA detection; electrochemical detection of microorganism-based DNA biosensors; gold nanoparticle-based electrochemical DNA biosensors; electrochemical detection of the aptamer-target interaction; nanoparticle-induced catalysis for DNA biosensing; basic terms regarding electrochemical DNA (nucleic acids) biosensors; screen-printed electrodes for electrochemical DNA detection; application of field-effect transistors to label free electrical DNA biosensor arrays; and electrochemical detection of nucleic acids using branched DNA amplifiers.

Download or read book General Methods in Biomarker Research and their Applications written by Victor R. Preedy and published by Springer. This book was released on 2015-08-14 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past decade there has been a major sea change in the way disease is diagnosed and investigated due to the advent of high throughput technologies, such as microarrays, lab on a chip, proteomics, genomics, lipomics, metabolomics etc. These advances have enabled the discovery of new and novel markers of disease relating to autoimmune disorders, cancers, endocrine diseases, genetic disorders, sensory damage, intestinal diseases etc. In many instances these developments have gone hand in hand with the discovery of biomarkers elucidated via traditional or conventional methods, such as histopathology or clinical biochemistry. Together with microprocessor-based data analysis, advanced statistics and bioinformatics these markers have been used to identify individuals with active disease or pathology as well as those who are refractory or have distinguishing pathologies. New analytical methods that have been used to identify markers of disease and is suggested that there may be as many as 40 different platforms. Unfortunately techniques and methods have not been readily transferable to other disease states and sometimes diagnosis still relies on single analytes rather than a cohort of markers. There is thus a demand for a comprehensive and focused evidenced-based text and scientific literature that addresses these issues. Hence the formulation of Biomarkers in Disease. The series covers a wide number of areas including for example, nutrition, cancer, endocrinology, cardiology, addictions, immunology, birth defects, genetics and so on. The chapters are written by national or international experts and specialists.

Download or read book Functionalized Nanomaterials written by Vineet Kumar and published by CRC Press. This book was released on 2021-07-28 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanomaterials contain some unique properties due to their nanometric size and surface functionalization. Nanomaterial functionalization also affects their compatibility to biocompatibility and toxicity behaviors. environment and living organism. This makes functionalized nanomaterials a material with huge scope and few challenges. This book provides detailed information about the nanomaterial functionalization and their application. Recent advancements, challenges and opportunities in the preparation and applications of functionalized nanomaterials are also highlighted. This book can serve as a reference book for scientific investigators, doctoral and post-doctoral scholars; undergrad and grad. This book is very useful for multidisciplinary researchers, industry personnel’s, journalists, and policy makers. Features: Covers all aspects of Nanomaterial functionalization and its applications Describes and methods of functionalized nanomaterials synthesis for different applications Discusses the challenges, recent findings, and cutting-edge global research trends on functionalization of nanomaterials and its applications It discusses the regulatory frameworks for the safe use of functionalized nanomaterials. It contains contributions from international experts from multiple disciplines.

Download or read book Nucleic Acids written by Victor A. Bloomfield and published by Sterling Publishing Company. This book was released on 2000-04-17 with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing a comprehensive account of the structures and physical chemistry properties of nucleic acids, with special emphasis on biological function, this text has been organized to meet the needs of those who have only a basic understanding of physical chemistry and molecular biology.