Fabrication and Characterization of a Plasmonic Biosensor Using Non-spherical Metal Nanoparticles PDF Download

Author: Bong-Su Jung
Publisher:
ISBN:
Category : Nanoparticles
Languages : en
Pages : 256

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Book Description
Label-free detection techniques have an important role in many applications, such as situations where few molecules -- rather than low molarity -- need to be detected, such as in single-cell screening. While surface plasmon resonance (SPR) scattering from metal nanoparticles has been shown to achieve significantly higher sensitivity in gene arrays, such an approach has not been demonstrated for protein arrays. SPR-based sensors could either use simple absorption measurement in a UV-Vis spectrometer or possibly surfaceenhanced Raman spectroscopy as the detection mechanism for molecules of interest. However, non-spherical particles are needed to achieve high sensitivity and field enhancement that is a requirement in both techniques, but these shapes are not easy toproduce reproducibly and preserve for extended periods of time. Here I present a carbonbased template-stripping method combined with nanosphere lithography (NSL). This fabrication allows to preserve the sharp features in atomically flat surfaces which are a composite of a non-spherical metal nano-particle (gold or silver) and a transparent embedding material such as glass. The stripping process is residue-free due to the introduction of a sacrificial carbon layer. The nanometer scale flat surface of our template stripping process is also precious for general protein absorption studies, because an inherent material contrast can resolve binding of layers on the 2 nm scale. These nanocomposite surfaces also allow us to tailor well-defined SPR extinction peaks with locations in the visible or infrared spectrum depending on the metal and the particle size and the degree of non-symmetry. As the particle thickness is reduced and the particle bisector length is increased, the peak position of the resonance shifts to the red. Not only the peak position shifts, but also the sensitivity to environmental changes increases. Therefore, the peak position of the resonance spectrum is dependent on the dielectric environmental changes of each particle, and the particle geometries. The resulting silver or gold nanoparticles in the surface of a glass slide are capable of detecting thiol surface modification, and biotin-streptavidin protein binding events. Since each gold or silver particle principally acts as an independent sensor, on the order of a few thousand molecules can be detected, and the sensor can be miniaturized without loss of sensitivity. UNSL-Au metal nanoparticle (MNP) sensors achieve the sensitivity of close to 300 nm/RIU which is higher than any other report of localized surface plasmon resonance (LSPR) sensors except gold nanocrescents. Finite-difference-time-domain (FDTD) and finite-element-method (FEM) numerical calculations display the influence of the sharp features on the resonance peak position. The maximum near-field intensity is dependent on the polarization direction, the sharpness of the feature, and the near-field confinement from the substrate. 3D FDTD simulation shows the local refractive index sensitivity of the gold truncated tetrahedron, which is in agreement with our experimental result. Both experimental and numerical calculations show that each particle can act as its own sensor.

Author: Kyunghee Cho
Publisher:
ISBN: 9781321646061
Category :
Languages : en
Pages : 120

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Book Description
The work presented in this dissertation covers two types of nanomaterials (nanostructured arrays on surfaces and nanoparticle suspensions) with a unified focus on biosensing applications utilizing surface plasmon resonance (SPR), a surface sensitive phenomenon that occurs at the nanoscale. The first part of the dissertation describes the fabrication of lithographically patterned and electrochemically deposited large-scale arrays of nanorings and split nanorings. The fabrication and characterization of nanoring arrays made from a host of materials such as Ni, Au, Co, and polydopamine are discussed. Additionally, the fabrication of split nanoring arrays with potential applications as a tunable dichroic is explained. The application of plasmonic gold nanoring arrays as a biosensor to detect DNA hybridization with detection capabilities down to 50 pM of DNA follows. The next part of this dissertation shifts focus from nanostructured surfaces to the detection of nanoparticles in suspension using surface plasmon resonance microscopy (SPRM). Specifically, polymeric hydrogel nanoparticles that have been engineered to bind the hexacosa peptide melittin is studied. Point diffraction patterns in sequential real-time SPRM differential reflectivity images are counted to create digital adsorption binding curves of single 220 nm diameter hydrogel nanoparticles from picomolar nanoparticle solutions onto alkanethiol-modified gold surfaces. The SPRM responses from the adsorption of hundreds of individual hydrogel nanoparticles are quantified to measure the loading of melittin, a potential therapeutic compound, into the nanoparticles. Additional bulk fluorescence measurements of melittin uptake into the hydrogel nanoparticles are used to correlate the maximum signal observed by SPRM to the incorporation of approximately 65,000 molecules into each 220 nm hydrogel nanoparticle, corresponding to roughly 4% of its volume.

Author: Peter Rodgers
Publisher: World Scientific
ISBN: 9814466867
Category : Technology & Engineering
Languages : en
Pages : 367

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Book Description
This book contains 35 review articles on nanoscience and nanotechnology that were first published in Nature Nanotechnology, Nature Materials and a number of other Nature journals. The articles are all written by leading authorities in their field and cover a wide range of areas in nanoscience and technology, from basic research (such as single-molecule devices and new materials) through to applications (in, for example, nanomedicine and data storage).

Author: Maryam Khodami
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
In this thesis by articles, I propose and demonstrate the full design, fabrication and characterization of optical biosensors based on (Bloch) Long Range Surface Plasmon Polaritons (LRSPPs). Gold waveguides embedded in CYTOP with an etched microfluidic channel supporting LRSPPs and gold waveguides on a one-dimensional photonic crystal (1DPC) supporting Bloch LRSPPs are exploited for biosensing applications. Straight gold waveguides embedded in CYTOP supporting LRSPPs as a biosensor, are initially used to measure the kinetics constants of protein-protein interactions. The kinetics constants are extracted from binding curves using the integrated rate equation. Linear and non-linear least squares analysis are employed to obtain the kinetics constants and the results are compared. The device is also used to demonstrate enhanced assay formats (sandwich and inhibition assays) and protein concentrations as low as 10 pg/ml in solution are detected with a signal-to-noise ratio of 20 using this new optical biosensor technology. CYTOP which has a refractive index close to water is the fluoropolymer of choice in current state of the art waveguide biosensors. CYTOP has a low glass transition temperature which introduces limitations in fabrication processes. A truncated 1D photonic crystal can replace a low-index polymer cladding such as CYTOP, to support Bloch LRSPPs within the bandgap of the 1DPC over a limited ranges of wavenumber and wavelength. Motivated by quality issues with end facets, we seek to use grating couplers in a broadside coupling scheme where a laser beam emerging from an optical fiber excites Bloch LRSPPs on a Au stripe on a truncated 1D photonic crystal. Adiabatic and non-adiabatic flared stripes accommodating wide gratings size-matched to an incident Gaussian beam are designed and compared to maximise the coupling efficiency to LRSPPs. The gratings are optimized, initially, through 2D modelling using the vectorial finite element method (FEM). Different 3D grating designs were then investigated via 3D modelling using the vectorial finite difference time domain (FDTD) method. Given their compatibility with planar technologies, gratings and waveguides can be integrated into arrays of biosensors enabling multi-channel biosensing. A multi-channel platform can provide, e.g., additional measurements to improve the reliability in a disease detection problem. Thus, a novel optical biosensor based on Bloch LRSPPs on waveguide arrays integrated with electrochemical biosensors is presented. The structures were fabricated on truncated 1D photonic crystals comprised of 15 period stack of alternating layers of SiO2/Ta2O5. The optical biosensors consist of Au stripes supporting Bloch LRSPPs and integrate grating couplers as input/output means. The Au stripes also operate as a working electrode in conjunction with a neighboring Pt counter electrode to form an electrochemical sensor. The structures were fabricated using bilayer lift-off photolithography and the gratings were fabricated using overlaid e-beam lithography. The planar waveguides are integrated into arrays capable of multichannel biosensing. The wafer is covered with CYTOP as the upper cladding with etched microfluidic channels, and wafer-bonded to a borofloat silica wafer to seal the fluidic channels and enable side fluidic interfaces. The proposed device is capable in principle of simultaneous optical and electrochemical sensing and could be used to address disease detection problems using a multimodal strategy.

Author: Nguyen Hoang Le
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Noble metal nanoparticles exhibit unique optical properties arising from the resonant oscillations of their conduction electrons with light. This phenomenon is called localized surface plasmon resonance (LSPR). The LSPR frequency is extremely sensitive to the size, shape, refractive index at the metal-dielectric interface, and other nearby metal nanoparticles. In an assembly of proximal nanoparticles, the LSPR of individual particles can couple to yield enhanced light scattering and large spectral shifts, which are useful for many applications including diagnostics and sensing. This dissertation presents a complex nanostructure comprising a core gold nanoparticle surrounded by multiple satellite gold nanoparticles for biosensing application. Chapter 2 introduces the fabrication and characterization of the core-satellite assemblies via a layer-by-layer process. Using ATP-aptamer as the linker, we demonstrated the detection of ATP based on the disassembly of the nanostructure, which can be readily captured by darkfield microscopy. The detection limit, dynamic range, and sensitivity can be tuned by controlling the size of the assembly. We found that the aptamer-linked nanoparticle assemblies were selective to only ATP, and not other adenine-containing compounds. Additionally, sensing of ATP in buffer and in bulk cell lysates was demonstrated. Chapter 3 presents the methodology for detecting ATP directly from lysed cells, down to the single-cell level without the need for purification or extraction. The intracellular ATP levels of two ovarian cancer cell lines were quantified to elucidate the differences and cellular distribution, and the potential of the stick-and-peel platform for mapping the microenvironment of 2D heterogeneous surfaces was demonstrated. In chapter 4, the optical properties of nanoparticle assemblies were tuned by changing the morphology of the nano building block, where the incorporation of gold nanoshells as satellites led to an extended redshift of LSPR to a much longer wavelength compared with using solid gold nanoparticles as satellites. This tunability in the LSPR of the assemblies allows for color-based analysis and color-coding of the plasmonic sensors. Lastly, Chapter 5 outlines the development of a multiplexed assay using the nanoparticle assemblies. Two types of assemblies, targeting either ATP or a nucleic acid (DNA-210), were fabricated with different DNA linkers in the same sensing area. The multiplexing was demonstrated by the selective disassembly process. Moreover, the ability to tune the optical properties of nanostructures using different morphologies was integrated; two different morphology of nanostructures, i.e. solid-solid and solid-shell nanostructures, for two targets, ATP and DNA-210, respectively, were fabricated. Based on a difference in scattered color, two types of biosensors among thousands of nanoparticle assemblies can be easily identified. Finally, we demonstrated duplex detection based on the change in the scattering intensity and the color read-out. Reflecting on the contributions of our work, this dissertation advances the fundamental knowledge and practical design of chip-based sensing platforms comprising complex plasmonic nanostructures. The work contributes to the sensing field by addressing some of the challenges in point-of-care or point-of-need measurement applications and provides an alternative bioanalytical tool for single-cell based analysis.

Author: G. Shvets
Publisher: World Scientific
ISBN: 9814355283
Category : Science
Languages : en
Pages : 469

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Book Description
Manipulation of plasmonics from nano to micro scale. 1. Introduction. 2. Form-Birefringent metal and its plasmonic anisotropy. 3. Plasmonic photonic crystal. 4. Fourier plasmonics. 5. Nanoscale optical field localization. 6. Conclusions and outlook -- 11. Dielectric-loaded plasmonic waveguide components. 1. Introduction. 2. Design of waveguide dimensions. 3. Sample preparation and near-field characterization. 4. Excitation and propagation of guided modes. 5. Waveguide bends and splitters. 6. Coupling between waveguides. 7. Waveguide-ring resonators. 8. Bragg gratings. 9. Discussion-- 12. Manipulating nanoparticles and enhancing spectroscopy with surface plasmons. 1. Introduction. 2. Propulsion of gold nanoparticles with surface plasmon polaritons. 3. Double resonance substrates for surface-enhanced raman spectroscopy. 4. Conclusions and outlook -- 13. Analysis of light scattering by nanoobjects on a plane surface via discrete sources method. 1. Introduction. 2. Light scattering by a nanorod. 3. Light scattering by a nanoshell. 4. Summary -- 14. Computational techniques for plasmonic antennas and waveguides. 1. Introduction. 2. Time domain solvers. 3. Frequency domain solvers. 4. Plasmonic antennas. 5. Plasmonic waveguides. 6. Advanced structures. 7. Conclusions

Author: Frances S. Ligler
Publisher: Elsevier
ISBN: 0080564941
Category : Science
Languages : en
Pages : 721

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Book Description
Optical Biosensors, Second Edition describes the principles of successful systems, examples of applications, and evaluates the advantages and deficiencies of each. It also addresses future developments on two levels: possible improvements in existing systems and emerging technologies that could provide new capabilities in the future. The book is formatted for ease of use and is therefore suitable for scientists and engineers, students and researcher at all levels in the field. - Comprehensive analysis and review of the underlying principles by optical biosensors - Updates and informs on all the latest developments and hot topic areas - Evaluates current methods showing the advantages and disadvantages of various systems involved

Author: Igor Linkov
Publisher: Springer Science & Business Media
ISBN: 1402094914
Category : Technology & Engineering
Languages : en
Pages : 459

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Book Description
Many potential questions regarding the risks associated with the development and use of wide-ranging technologies enabled through engineered nanomaterials. For example, with over 600 consumer products available globally, what information exists that describes their risk to human health and the environment? What en- neering or use controls can be deployed to minimize the potential environmental health and safety impacts of nanomaterials throughout the manufacturing and product lifecycles? How can the potential environmental and health benefits of nanotechnology be realized and maximized? The idea for this book was conceived at the NATO Advanced Research Workshop (ARW) on “Nanomaterials: Environmental Risks and Benefits and Emerging Consumer Products. ” This meeting – held in Algarve, Portugal, in April 2008 – started with building a foundation to harmonize risks and benefits associated with nanomaterials to develop risk management approaches and policies. More than 70 experts, from 19 countries, in the fields of risk assessment, decision-analysis, and security discussed the current state-of-knowledge with regard to nanomaterial risk and benefits. The discussion focused on the adequacy of available risk assessment tools to guide nanomaterial applications in industry and risk governance. The workshop had five primary purposes: Describe the potential benefits of nanotechnology enabled commercial products. Identify and describe what is known about environmental and human health risks of nanomaterials and approaches to assess their safety. Assess the suitability of multicriteria decision analysis for reconciling the benefits and risks of nanotechnology.

Author: Kuriyan, John
Publisher: W.W. Norton & Company
ISBN: 0815341881
Category : Science
Languages : en
Pages : 15

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Book Description
This textbook provides an integrated physical and biochemical foundation for undergraduate students majoring in biology or health sciences. It is particularly suitable for students planning to enter the pharmaceutical industry. This new generation of molecular biologists and biochemists will harness the tools and insights of physics and chemistry to exploit the emergence of genomics and systems-level information in biology, and will shape the future of medicine.

Author: Chris D. Geddes
Publisher: John Wiley & Sons
ISBN: 0470642785
Category : Science
Languages : en
Pages : 655

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Book Description
Discover how metal-enhanced fluorescence is changing traditional concepts of fluorescence This book collects and analyzes all the current trends, opinions, and emerging hot topics in the field of metal-enhanced fluorescence (MEF). Readers learn how this emerging technology enhances the utility of current fluorescence-based approaches. For example, MEF can be used to better detect and track specific molecules that may be present in very low quantities in either clinical samples or biological systems. Author Chris Geddes, a noted pioneer in the field, not only explains the fundamentals of metal-enhanced fluorescence, but also the significance of all the most recent findings and models in the field. Metal-enhanced fluorescence refers to the use of metal colloids and nanoscale metallic particles in fluorescence systems. It offers researchers the opportunity to modify the basic properties of fluorophores in both near- and far-field fluorescence formats. Benefits of metal-enhanced fluorescence compared to traditional fluorescence include: Increased efficiency of fluorescence emission Increased detection sensitivity Protect against fluorophore photobleaching Applicability to almost any molecule, including both intrinsic and extrinsic chromophores Following a discussion of the principles and fundamentals, the author examines the process and applications of metal-enhanced fluorescence. Throughout the book, references lead to the primary literature, facilitating in-depth investigations into particular topics. Guiding readers from the basics to state-of-the-technology applications, this book is recommended for all chemists, physicists, and biomedical engineers working in the field of fluorescence.