Download or read book Fabrication and Testing of Surface enhanced Raman Spectroscopy Substrates for the Detection of Biomolecules written by Robert F. Peters and published by . This book was released on 2014 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biosensing involves the detection of analytes using biological elements as receptor agents for the specific binding of molecules to a surface. Surface-enhanced Raman spectroscopy (SERS), a surface-sensitive vibrational spectroscopy technique used to amplify Raman signals, provides unique advantages for biosensing. Unique Raman fingerprint spectra of targeted molecules allows for accurate identification of unknown samples. Inconsistencies in Raman signal enhancements, however, due to the irregularities of metallic features at the nanoscale, is a significant challenge with SERS. Nanofabrication technologies, including electron beam lithography (EBL) and nanoimprint lithography (NIL), provide resolution capabilities at the nanoscale. In this work, nanofabrication methods were used to fabricate SERS substrates for the detection of analytes using various immobilization strategies. Control over signal intensity and detection of biological bonding, with analytes in aqueous solutions was demonstrated. Investigations and testing of various aspects in the fabrication processes allowed for significant control over features at nanoscale dimensions.

Download or read book Fabrication of Surface Enhanced Raman Scattering SERS Substrates Made from Nanoparticle Printing Inks for Detection of Biological Molecules written by Manuel Alejandro Figueroa and published by . This book was released on 2013 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface enhanced Raman scattering ΔΟΠ� ϝαπ ϛδλδοαϟδγ ϛοδαϟ ζλϟδοδπϟ απ α προεαϐδ αλαιυϟζϐαι ϟδϐϝλζξρδ βδϐαρπδ ζϟ ϐαλ νομγρϐδ ακνιζεζϐαϟζμλ εαϐϟμοπ βδϟςδδλ »«��»«»“� Πζισδο αλγ ϛμιγ αοδ ϟϝδ κμπϟ ςζγδιυ ρπδγ ϐμκνμλδλϟπ απ ϟϝδζο πζφδ αλγ πϟορϐϟροδ αιιμςπ εμο ιζϛϝϟ ϟμ ζλγρϐδ ϐμλγρϐϟζμλ διδϐϟομλπ ϟμ μπϐζιιαϟδ ιμϐαιιυ ςζϟϝζλ ϟϝδ λαλμναοϟζϐιδ πϟορϐϟροδ� �ϝδλ α κμιδϐριδ ιζδπ ζλ ϟϝδ ζλϟδοναοϟζϐιδ πναϐδ βδϟςδδλ ϟςμ λαλμναοϟζϐιδπ� ϝζϛϝιυ γδϟαζιδγ σζβοαϟζμλαι ζλεμοκαϟζμλ βδϐμκδπ γδϟδϐϟαβιδ� Ϟϝδ μβηδϐϟζσδ με ϟϝζπ πϟργυ ζπ ϟμ οδνομγρϐζβιυ εαβοζϐαϟδ πρϐϝ αλ αοοαλϛδκδλϟ ζλ α λαλμναοϟζϐιδ πρβπϟοαϟδ ςϝζιδ καζλϟαζλζλϛ πϟαβζιζϟυ� Ζλ ϟϝζπ ςμοθ� λαλμναοϟζϐιδ νοζλϟζλϛ ζλθπ �� ϐμιιμζγαι λαλμναοϟζϐιδπ δλϐανπριαϟδγ βυ α πϟαβζιζφζλϛ ιζϛαλγ �� αοδ ρπδγ απ ϟϝδ καζλ ϐμκνμλδλϟ με ΠΔΟΠ πρβπϟοαϟδπ� Ϟϝδ ιζϛαλγ πϝδιι ζπ ναοϟζαιιυ οδκμσδγ βυ ϐμλϟομιιδγ ϝδαϟζλϛ� ςϝζϐϝ οδγρϐδπ πναϐζλϛ βδϟςδδλ λαλμναοϟζϐιδπ ϐοδαϟζλϛ α βομαγ γζπϟοζβρϟζμλ με ζλϟδοναοϟζϐιδ γζπϟαλϐδπ� Πζκζιαο ϟμ εοαϐϟαι αϛϛοδϛαϟδπ ϟϝζπ αοοαλϛδκδλϟ αιιμςπ ιμϐαιζφδγ νιαπκμλπ ϟμ λαϟροαιιυ οδπμλαϟδ μσδο α βομαγ οαλϛδ με πνδϐϟοαι εοδξρδλϐζδπ� Κζϐομςασδ αβπμονϟζμλ ζπ αννιζδγ απ α λμλ�ζλσαπζσδ κδϟϝμγ ϟμ πδλπζϟζσδιυ κμλζϟμο λαλμναοϟζϐιδ πζλϟδοζλϛ ζλ μογδο ϟμ ϛαρϛδ ϟϝδ πρβπϟοαϟδπ ͅϟρλζλϛ εμο ιαοϛδ ακνιζεζϐαϟζμλ εαϐϟμοπ� Ϟϝδ ϛιμβαι αοοαλϛδκδλϟ με λαλμναοϟζϐιδπ ϝαπ αιςαυπ βδδλ γζεεζϐριϟ ϟμ κδαπροδ γροζλϛ ϝδαϟζλϛ ϟϝομρϛϝ Γ� οδπζπϟζσζϟυ κδαπροδκδλϟπ αλγ προεαϐδ ζκαϛζλϛ ϟδϐϝλζξρδπ� Κζϐομςασδ αβπμονϟζμλ μϐϐροπ ζλ ϟϝδ ςδαθ οδπζπϟζσδ ιζλθπ εμοκδγ βδϟςδδλ ναοϟζϐιδπ γροζλϛ πζλϟδοζλϛ γρδ ϟμ ϟϝδ κζϐομςασδ ιμππδπ ζλ ιμμπδιυ ϐμρνιδγ ναοϟζϐιδπ� Βυ νιαϐζλϛ ϟϝδ πρβπϟοαϟδ ζλ α κζϐομςασδ ϐασζϟυ� αβπμονϟζμλ ϐαλ βδ κμλζϟμοδγ ϛιμβαιιυ γροζλϛ ϝδαϟζλϛ� Ϟϝδ ιαοϛδπϟ ΠΔΟΠ ακνιζεζϐαϟζμλ εαϐϟμοπ μϐϐρο αϟ α πϟαϛδ ζκκδγζαϟδιυ νοδϐδγζλϛ ϟϝδ ιαοϛδπϟ κζϐομςασδ αβπμονϟζμλ ϛαζλπ� Ϟϝζπ νομσζγδπ α ρπδερι κδϟϝμγ εμο γδϟδοκζλζλϛ α ϟϝδοκαι ςζλγμς εμο ϝδαϟζλϛ ςϝδλ μνϟζκζφζλϛ ΠΔΟΠ πρβπϟοαϟδπ� Εζλαιιυ� ϟϝδπδ μνϟζκζφδγ ΠΔΟΠ πρβπϟοαϟδπ αοδ ρπδγ ϟμ γδϟδϐϟ ϝυαιρομλζϐ αϐζγ� Ϟϝζπ ϐμκνιδτ κμιδϐριδ ζπ α νμϟδλϟζαι βζμκαοθδο εμο ζλειακκαϟμου γζπδαπδπ βρϟ ζϟ ϝαπ μλιυ βδδλ γδϟδϐϟδγ αϟ α ϐμλϐδλϟοαϟζμλ με ͵ κϛ�κΙ μλ ϐμκκδοϐζαιιυ ασαζιαβιδ ΠΔΟΠ πρβπϟοαϟδπ� Ϝδοδ ζϟ ζπ πϝμςλ ϟϝαϟ ερλϐϟζμλαιζφζλϛ ϟϝδ ΠΔΟΠ πρβπϟοαϟδ ςζϟϝ α πδιε�αππδκβιδγ κμλμιαυδο ιμςδοπ ϟϝδ ιζκζϟ με γδϟδϐϟζμλ ϟμ ͵« �ơϛ�κΙ� ΠΔΟΠ αλαιυπζπ αιπμ νομσζγδπ πϟορϐϟροαι γδϟαζιπ αβμρϟ ϟϝδ ϐμλεμοκαϟζμλ με ϟϝδ κμιδϐριδ γροζλϛ αγπμονϟζμλ�

Download or read book Surface Enhanced Raman Spectroscopy Biosensing and Diagnostic Technique for Healthcare Applications written by Swati Jain and published by Bentham Science Publishers. This book was released on 2021-12-28 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface enhanced Raman spectroscopy (SERS) is a technique applied in multidisciplinary research. Its use has tremendously grown in the last 40 years owing to improved nanofabrication, biomolecules extraction and sensitive signal acquisition techniques. This book focuses on the underlying principles of SERS by emphasizing on basic concepts and background information about the subject. Chapters explain the physics of Raman spectroscopy while also indicating its relevance to designing protocols and methodologies for biosensing and imaging. The book gives updated and recent details on colloids and nanostructures, their fabrication, surface engineering and immobilization methods, all in context to SERS based biosensing. Key Features: - Covers basic knowledge and new research about surface enhanced Raman spectroscopy (SERS) - Provides a complete framework on SERS based biosensing with concise chapters - Focuses on different active molecules critical to SERS and associated developed nanoassemblies - Presents information about ongoing research on SERS imaging applications - Highlights bottlenecks of SERS technique in biosensing - Includes references for further reading This book serves as a reference book for researchers and academicians and will also provide a reasonable understanding on the topic of SERS to newcomers irrespective of their background in a simple manner. The book is of interest to all readers within the scientific community involved with Raman spectroscopy, including chemists, physicists, biologists, material scientists as well as biomedical engineers.

Download or read book Surface Enhanced Raman Spectroscopy written by Marek Prochazka and published by Springer. This book was released on 2015-12-12 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives an overview of recent developments in RS and SERS for sensing and biosensing considering also limitations, possibilities and prospects of this technique. Raman scattering (RS) is a widely used vibrational technique providing highly specific molecular spectral patterns. A severe limitation for the application of this spectroscopic technique lies in the low cross section of RS. Surface-enhanced Raman scattering (SERS) spectroscopy overcomes this problem by 6-11 orders of magnitude enhancement compared with the standard RS for molecules in the close vicinity of certain rough metal surfaces. Thus, SERS combines molecular fingerprint specificity with potential single-molecule sensitivity. Due to the recent development of new SERS-active substrates, labeling and derivatization chemistry as well as new instrumentations, SERS became a very promising tool for many varied applications, including bioanalytical studies and sensing. Both intrinsic and extrinsic SERS biosensing schemes have been employed to detect and identify small molecules, nucleic acids and proteins, and also for cellular and in vivo sensing.

Download or read book Frontiers of Surface Enhanced Raman Scattering written by Yukihiro Ozaki and published by John Wiley & Sons. This book was released on 2014-02-19 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive presentation of Surface-Enhanced Raman Scattering (SERS) theory, substrate fabrication, applications of SERS to biosystems, chemical analysis, sensing and fundamental innovation through experimentation. Written by internationally recognized editors and contributors. Relevant to all those within the scientific community dealing with Raman Spectroscopy, i.e. physicists, chemists, biologists, material scientists, physicians and biomedical scientists. SERS applications are widely expanding and the technology is now used in the field of nanotechnologies, applications to biosystems, nonosensors, nanoimaging and nanoscience.

Download or read book Advanced Substrate Design for Label free Detection of Trace Organic and Biological Molecules written by Zachary Allen Combs and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To truly realize and exploit the extremely powerful information given from surface-enhanced Raman scattering (SERS) spectroscopy, it is critical to develop an understanding of how to design highly sensitive and selective substrates, produce specific and label-free spectra of target analytes, and fabricate long-lasting and in-the-field ready platforms for trace detection applications. The study presented in this dissertation investigated the application of two- and three-dimensional substrates composed of highly-ordered metal nanostructures. These systems were designed to specifically detect target analytes that would enable the trace, label-free, and real-time detection of chemicals and biomolecules. Specifically, this work provides new insight into the required properties for maximizing electromagnetic and chemical Raman enhancement in three-dimensional porous alumina substrates by designing metal nanostructure shape, density, aggregated state, and most importantly aligning the substrate pore size with the excitation wavelength used for plasmonic enhancement leading to the ppb detection of vapor phase hazardous chemicals. A new micropatterned silver nanoparticle substrate fabricated via soft lithography with specific functionalization was developed, which allows the simultaneous analyte and background detection for trace concentrations of the target biomolecule, immunoglobulin G. Also, a novel functionalized SERS hot spot fabrication technique, which utilizes highly specific aptamers as both the mediator for electrostatic assembly of gold nanoframe dimers as well as the biorecognition element for the target, riboflavin, to properly locate the tethered biomolecule within the enhanced region for trace detection, was demonstrated. We suggest that the understanding of SERS phenomena that occur at the interface of nanostructures and target molecules combined with the active functionalization and organization of metal nanostructures and trace detection of analytes discussed in this study can provide important insight for addressing some of the challenges facing the field of SERS sensor design such as high sensitivity and selectivity, reliable and repeatable label-free identification of spectral peaks, and the well-controlled assembly of functional metal nanostructures. This research will have a direct impact on the future application of SERS sensors for the trace detection of target species in chemical, environmental, and biomedical fields through the development of specific design criteria and fabrication processes.

Download or read book Fabrication and Testing of Advanced Substrates for Surface Enhanced Raman Scattering SERS written by Angelia K. Moore and published by . This book was released on 1990 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dry and Wet Surface Enhanced Raman Scattering Substrates written by Ahmed Mahmoud and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past few decades, surface enhanced Raman scattering (SERS) has been evolving as a powerful analytical technique for the detection of a wide of chemical and biological molecules. The technique can reach a sensitivity of single molecule detection, which triggered plenty of ongoing research. In addition, technological advancements in photonics and nanoscience have resulted in the advent of portable and handheld Raman systems. These devices help SERS analysis move from expensive heavy-equipped research labs to low cost field deployable-research. The development of efficient SERS substrates that can provide signal enhancement by many orders of magnitude is a core component for SERS. The SERS substrates market and research are generally dominated by rigid solid substrates that are fabricated mostly by micro/nanofabrication techniques. Although these methods can provide reproducible substrates, they suffer from usability constraints because of their high cost of fabrication. The work presented in this thesis explored cost-effective approaches to develop and optimize SERS substrates. The substrates investigated are divided into two main categories, membrane-based SERS substrates and in-solution SERS substrates. The membrane-based SERS substrates were fabricated by equipment-free methods. In these deviceless methods, gold and silver nanostructures were incorporated in-situ within the micropores of polyvinylidene fluoride (PVDF) membranes by seed mediated and seedless protocols, respectively. The SERS performance of these substrates was investigated and optimized by controlling the loading of plasmonic nanostructures. These flexible inexpensive substrates have the advantages of being easy to fabricate and to use. In addition, the variation in the SERS performance of these substrate was less than 20% within the same substrate and from substrate-to-substrate, which reflects acceptable reproducibility. Analytical applications of these substrates were demonstrated using a Raman microscope as well as a handheld Raman spectrometer. The second category of the SERS substrates studied was based on the optimization of gold nanostars and graphene-silver nanocomposites for water dispersible SERS measurements. In-solution SERS platforms are not used as commonly as solid-based substrates; however, these wet platforms can provide some advantages over the dried-based ones in terms of cost, reproducibility, and analysis time. The SERS performance of gold nanostars with different branch lengths was optimized based on the type of Good's buffer, the ratio of buffer to gold concentration, and their aggregation. Our results were counterintuitive in that the gold nanostars with the shorter branches provided the largest in-solution SERS intensity. These findings can be attributed to higher surface coverage of the Raman probe rather than enhanced electromagnetic effects. Graphene-silver nanocomposites were investigated also as in-solution SERS substrates with a large 2D surface area. The SERS behavior of these nanocomposites were studied using graphene, a thiolated Raman probe, and a dye labelled ssDNA to simulate different possible interactions. The SERS and plasmonic performance of these nanocomposites can be tuned by the size of silver nanoparticles on these substrates. The nanocomposites were more stable and showed superior SERS performance when compared to commercial silver nanoparticles. The contributions of this work can pave the way for flexible membrane-based and in-solution SERS substrates to be accompanied with a handheld Raman device for field-deployable SERS measurements.

Download or read book SOLUTION PROCESSABLE SURFACE ENHANCED RAMAN SPECTROSCOPY SERS SUBSTRATE written by Narayan Sharma and published by . This book was released on 2015 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface Enhanced Raman Spectroscopy is a powerful analytical tool to obtain information on molecular composition. This technique has advanced greatly since its discovery, allowing Raman spectroscopic analysis down to the detection of single molecule. The heart of SERS performance lies on the choice and fabrication of SERS substrate. The most investigated metals for SERS substrates are Au and Ag. Unfortunately, the fabrication of such devises poses a significant challenge due to an expensive deposition technology including, vapor deposition, electron-beam lithography, focused ion-beam lithography, and nano-transfer printing. Herein, we report a simple and low-cost solution processing method to fabricate SERS substrates. Au nanoparticles and Au/CdS core/shell nanoparticles were synthesized and their solutions deposited on glass plates in the form of nanoparticle films. Although the enhancement of Raman signal due to Ag nanoparticle substrates is greater than that of Au, the high stability and a wide variety of fabrication methods makes Au nanoparticles more favorable candidates for SERS substrates. The performance of the SERS substrates fabricated using this method was found to be comparable with the commercially available substrates.

Download or read book Surface Enhanced Vibrational Spectroscopy written by Ricardo Aroca and published by John Wiley & Sons. This book was released on 2006-05-01 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface Enhanced Vibrational Spectroscopy (SEVS) has reached maturity as an analytical technique, but until now there has been no single work that describes the theory and experiments of SEVS. This book combines the two important techniques of surface-enhanced Raman scattering (SERS) and surface-enhanced infrared (SEIR) into one text that serves as the definitive resource on SEVS. Discusses both the theory and the applications of SEVS and provides an up-to-date study of the state of the art Offers interpretations of SEVS spectra for practicing analysts Discusses interpretation of SEVS spectra, which can often be very different to the non-enhanced spectrum - aids the practicing analyst

Download or read book Evaluation of Substrates for Surface enhanced Raman Scattering written by Muyang Zhong and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface-enhanced Raman scattering (SERS) has long been the interest of researchers in chemistry, physics and engineering, especially since the discovery that SERS can probe into the system down to the single molecule (SM) level. Despite the large number of publications regarding the fabrication of SERS substrates, it has been a challenge in the field to quantify the SERS signal and universally compare substrates. Traditionally, enhancement factor (EF) is used as an indicator of substrate quality, but the EF calculation is hugely dependent on the estimation of the surface coverage and other factors that are determined largely subjectively. Therefore, this thesis aims at discussing other parameters that can also be used to evaluate different substrates. Six different SERS substrates of Ag or Au nanoparticles of different sizes were fabricated by nanosphere lithography (NSL) and characterized by electron microscopy and UV-vis spectroscopy. SERS substrates were mapped for different concentrations of a probe molecule. Through subsequent baseline correction and principle component analysis (PCA), the "intensity" of individual spectrum was obtained and the shapes of intensity histograms of each substrate were acquired.Instead of calculating EF, five criteria (six quantification methods in total) were employed to comprehensively evaluate the six substrates. These were density of hot spots (characterized by the number of zero-intensity events), enhancement (represented by mean intensity), spatial variation (calculated by RSD of intensity), repeatability (realized by cross correlation) and histogram shape (quantified by skewness and kurtosis). These new methods provide insights to the understanding of the properties of SERS substrates in terms of hot spots. Different substrates may exhibit better performance in terms of one criterion but worse in terms of others. Those variations in performance can be explained by their surface morphology.These more elaborated methods are believed to provide a more comprehensive approach to evaluate and compare substrates than the traditional EF values. The thesis also paves the way for future study on SM-SERS and fabricating better SERS substrates.

Download or read book The Rational Design and Lithographic Fabrication of Surface Enchanced i e Enhanced Raman Spectroscopy Substrates written by and published by . This book was released on 2008 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The analytical capabilities of surface-enhanced Raman spectroscopy (SERS) reside in the performance characteristics of the SERS-active substrate. Signal enhancement observed in SERS is attributable to the presence of noble metal nanostructures on substrate surfaces. The rational design and control of variables such as shape and size, and distribution, density, and spacing of these nanostructures can lead to substrates that have greater analytical sensitivity and yield more reproducible enhancement. Through systematic control of the morphology of our SERS substrates, we have created ordered periodic arrays as well as random aggregates of nanoscale particles using electron beam lithography (EBL). A unique aspect of these EBL-created substrates is that the morphology is known with great precision. Once fabricated, the arrays and/or aggregates are coated with a SERS-active noble metal through physical vapor deposition (PVD). Both the uniform and random lithographically produced nanopatterns are studied by surface enhanced Raman spectroscopy to examine the Stokes responses of various analytes, while scanning electron microscopy (SEM) is used to examine pattern surfaces post lithographic development and post noble metal deposition. In the case of the ordered structures, raw and normalized SERS data is seen to correlate with data from simple electrostatic calculations as well as the broad background continuum underlying each spectrum collected. Borrowing from the biological concepts of cloning and combinatorial chemistry, random morphology patterns are designed and spectrally mapped to locate "hot spots" within aggregates. Regardless of the type of substrate, ordered or random, by using EBL, the substrates can be reproducibly fabricated, yielding consistent analyte environments each time the substrate is created.

Download or read book Design and Fabrication of Integrated Plasmonic Platforms for Ultra sensitive Molecular and Biomolecular Detections written by Mohammadali Tabatabaei and published by . This book was released on 2015 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the major challenges in analytical and biological sciences is to develop a device to obtain unambiguous chemical and structural properties of a material or a probe biomolecule with high reproducibility and ultra-high sensitivity. Moreover, in addition to such a high sensitivity, other cases such as minimum intrusiveness, small amounts of analyte, and short acquisition time and high reproducibility are key parameters that can be valued in any analytical measurements. Among the promising methods to achieve such endeavor plasmon-mediated surface-enhanced spectroscopic techniques, such as surface-enhanced Raman spectroscopy (SERS), are considered as suitable options. Such techniques take advantage of the interaction between an optical field and a metallic nanostructure to magnify the electromagnetic (EM) field in the proximity of the nanostructure. This results in an amplified signal of the vibrational fingerprints of the adsorbed probe molecules onto the metallic surface. Keys to obtaining ultra-sensitive SERS measurements are the development of rationally-designed plasmonic nanostructures. Besides, a major challenge for controlled and reliable sensitive measurements of probe biomolecules on biological cells gives rise due to the intrinsic random positioning and proliferation of these cells over a substrate such as a glass coverslip. In this thesis, the rational design and development of a fluorocarbon thin film micropatterned platform is introduced for controlled programming of conventional and transfected cells proliferation over the substrate. They also provided high throughput capability of controlled neuronal network connections towards advanced imaging and sensitive detection of biomolecules of interest at nanoscale resolution. This micropatterned platform was also integrated with optimized plasmonic nanostructures fabricated by nanosphere lithography (NSL) for SERS biosensing of glycans using a Raman reporter over the positionally-controlled single cells surfaces. In addition to providing controlled plasmon-mediated measurements, the fabrications of two newly-developed 3D plasmonic nanostructures have been introduced in this thesis. These are nanopyramids arrays fabricated by NSL and arrays of nanoholes with co-registered nanocones fabricated by electron-beam lithography (EBL). These approaches have been used not only for ultra-sensitive molecular detection at the monolayer level in a variety of configurations, but also towards label-free single molecule detection at sub-femtomolar concentrations.

Download or read book Fabrication and Characterization of Substrate Materials for Trace Analytical Measurements by Surface Enhanced Raman Scattering SERS Spectroscopy Technique written by Pratima Vabbilisetty and published by . This book was released on 2008 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: The detection of various compounds using Surface enhanced Raman Scattering (SERS) from colloidal suspensions of silver and gold colloids has been attempted. Different substrates have been utilized and SERS spectra for R6G, creatinine, imidazole and benzoic acid have been evaluated as a function of time. SERS investigations have been performed using model compounds to allow comparison between the substrates. Different concentrations of R6G have been used for the valuation of the analytical capabilities. Silver and gold colloids have been prepared and used for SERS measurements and for the fabrication of substrates having a layer of immobilized metal nanoparticles.

Download or read book Fabrication of Surface Enhanced Raman Scattering Substrates by Controlled Assembly and Morphology Tuning of Gold Nanoparticles written by Agampodi Swarnapali De Silva Indrasekara and published by . This book was released on 2014 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design and fabrication of nanoparticles (NPs) and NP assemblies to sustain intense electromagnetic field enhancement for surface enhanced Raman scattering (SERS)-based imaging and sensing have recently gained significant attention. In SERS, the intrinsic optical properties of plasmonic NPs are used to overcome the relatively low Raman cross-sections and thereby increase sensitivity. Sharp features in anisotropic NPs and interparticle gaps within NP assemblies have been identified as the locations where the highest SERS enhancements can be achieved, also known as "hot spots". Many attempts have been reported that deal with the bottom-up assembly of NPs to achieve highly reproducible, sensitive, and well characterized SERS substrates, but it still remains a challenge to attain monodisperse, highly reproducible "hot spots" and directional assembly. The focus of this dissertation is to develop synthetic protocols for controlled engineering of NPs with SERS "hot spots", and thereby to contribute to the advancement of SERS-based sensing and imaging applications. In this dissertation, the development of SERS substrates has evolved from dimers of spherical gold NPs (SP), to star-shaped gold NPs (ST), and finally to assembled superstructures of ST and SPs. The kinetically controlled assembly of SPs into dimers was achieved by using Raman active dithiolated linker molecules, with the highest yield reported for this method to the best of our knowledge, leading to SERS tags with a reproducible SERS enhancement on the order of 105. NP dimers, surface-functionalized to target U87 glioblastoma cancer cells, demonstrated a fast, reliable, and selective SERS-based detection of the diseased cells that outperforms fluorescence. The morphology of the STs was modified to possess longer and sharper spikes with a narrower tip curvature thereby increasing the electromagnetic field localization at the tips. SERS substrates were designed by periodically and reproducibly immobilizing STs on a planar substrate with high surface coverage and limited to no clustering, thus enabling femtomolar detection of organic analytes with an outstanding 109 SERS enhancement. Finally, the core-satellite assemblies of ST with SPs were achieved through conjugation linker chemistry. These assemblies demonstrated SERS enhancement of two orders of magnitudes greater than isolated STs thereby improving the sensitivity of potential SERS-based imaging and sensing applications.

Download or read book Principles of Surface Enhanced Raman Spectroscopy written by Eric Le Ru and published by Elsevier. This book was released on 2008-11-17 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: SERS was discovered in the 1970s and has since grown enormously in breadth, depth, and understanding. One of the major characteristics of SERS is its interdisciplinary nature: it lies at the boundary between physics, chemistry, colloid science, plasmonics, nanotechnology, and biology. By their very nature, it is impossible to find a textbook that will summarize the principles needed for SERS of these rather dissimilar and disconnected topics. Although a basic understanding of these topics is necessary for research projects in SERS with all its many aspects and applications, they are seldom touched upon as a coherent unit during most undergraduate studies in physics or chemistry. This book intends to fill this existing gap in the literature. It provides an overview of the underlying principles of SERS, from the fundamental understanding of the effect to its potential applications. It is aimed primarily at newcomers to the field, graduate students, researchers or scientists, attracted by the many applications of SERS and plasmonics or its basic science. The emphasis is on concepts and background material for SERS, such as Raman spectroscopy, the physics of plasmons, or colloid science, all of them introduced within the context of SERS, and from where the more specialized literature can be followed. Represents one of very few books fully dedicated to the topic of surface-enhanced Raman spectroscopy (SERS) Gives a comprehensive summary of the underlying physical concepts around SERS Provides a detailed analysis of plasmons and plasmonics

Download or read book Chemical and Biochemical Applications written by Pierre Laszlo and published by Elsevier. This book was released on 2012-12-02 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: NMR of Newly Accessible Nuclei, Volume 1: Chemical and Biochemical Applications is a 10-chapter text that explores the properties, advantages, developments, and chemical and biochemical applications of NMR technique. This book describes first the operation of an NMR spectrometer under its two aspects, namely, the instrumental and the computational aspects. The next chapters are devoted to some of the most important pulse sequences. The discussion then shifts to the various factors determining the position of the observed absorption and those responsible for the various relaxation processes. The last chapters deal with the specific applications of NMR, including in cation salvation, calcium-binding proteins, polyelectrolyte systems, halogens, and antibiotic ionophores. This book is of value to inorganic and analytical chemists, and biophysicists.