Download or read book Development of Novel Substrates and Sampling Techniques for the Analysis of Drugs and Model Environmental Pollutants Via Surface Enhanced Raman Spectroscopy SERS written by Marco Antonio de Jesús and published by . This book was released on 2004 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Dissertation Abstracts International written by and published by . This book was released on 2004 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Novel Approaches to Prepare and Utilize Surface enhanced Raman Spectroscopy SERS Substrates written by and published by . This book was released on 2008 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past few decades, surface enhanced Raman spectroscopy (SERS) has garnered respect as an analytical technique with significant chemical and biological applications. SERS is important for the life sciences because it can provide trace level detection and a high level of molecular structure information. The development of quantitative, highly sensitive substrates requires control over size, shape, and position of metal nanoparticles which function as the SERS active medium. Thus, creating and successfully implementing a sensitive, reproducible, and robust SERS active substrate continues to be a challenging task. Its future development depends critically on techniques for lithography and nanofabrication. Herein, we report a novel method for SERS that is based upon using colloidal silver nanoparticles in a multiplexed microfluidics (MMFs) platform. The MMF is created in polydimethylsiloxane (PDMS) polymer material and used to perform parallel, high throughput, and sensitive detection/identification of single or various analytes under easily manipulated conditions. A facile passive pumping method is used to deliver samples into the channels under flowing conditions that are highly conducive for SERS measurments. Also an unconventional nanofabrication approach is modified to produce efficient SERS substrates. Metallic nanopatterns of silver discs are transferred from a stamp onto PDMS to create nanocomposite substrates with regular periodic morphologies. The stamp with periodic arrays of square, triangular, and elliptical pillars is created via Electron Beam Lithography of ma-N 2403 resist. A modified cyclodextrin is thermally evaporated on the stamp to overcome the adhesive nature of the ebeam resist and to function as a releasing layer. Subsequently, the stamp is over coated with Ag by physical vapor deposition at a controlled rate and thickness and used directly for nanotransfer printing (nTP). Stamps, substrates, and the efficiency of the nTP process were explored by SEM. Ag nano-disc-PDMS substrates are studied by SERS using Rhodamine 6G as the probe analyte. The SERS response of metallic nano-discs of various shapes/sizes on the original stamp is compared to the corresponding nTP substrates. We demonstrate that physical manipulation of the PDMS post nTP can be used to alter morphology. Additionally, stamps are shown to be reusable after the nTP process.
Download or read book Surface Enhanced Raman Spectroscopy for Biophysical Applications written by Claudia Fasolato and published by Springer. This book was released on 2018-12-05 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book explores the phenomenon of surface-enhanced Raman scattering (SERS), the huge amplification of Raman signal from molecules in the proximity of a metallic nanostructured surface, allowing readers to gain an in-depth understanding of the mechanisms affecting the spectroscopic response of SERS-active systems for effective applications. SERS spectroscopy is an ultrasensitive analytical technique with great potential for applications in the field of biophysics and nanomedicine. As examples, the author presents the design of nanocolloid-based SERS-active substrates for molecular sensing and of a folate-based SERS-active nanosensor capable of selectively interacting with cancer cells, enabling cancer diagnostics and therapy at the single-cell level. The author also suggests novel paths for the systematization of the SERS nanosystem design and experimental protocols to maximize sensitivity and reproducibility, which is essential when real-world biomedical applications are the goal of the study. With a combined approach, both fundamental and applied, and a detailed analysis of the state of the art, this book provides a valuable overview both for students new to SERS spectroscopy and for experts in the field.
Download or read book Raman and SERS Investigations of Pharmaceuticals written by Monica Baia and published by Springer Science & Business Media. This book was released on 2008-06-11 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last several years it has become apparent to most researchers that interdisciplinary research is the key to success in the sciences’ future. The present book exemplifies such interdisciplinary work. Thus, some new derivatives have been prepared by chemists and consecutively analyzed by physicists in order to better understand their physical-chemical properties for future tests to be performed by pharmacists. The book consists of an introductory section and other eight chapters. First, the fundamentals of infrared, Raman and surface-enhanced Raman spectroscopy and those of the theoretical methods employed for the vibrational prediction modes are highlighted. The SERS investigations illustrated in the following chapters are focused on different kinds of drugs: tranquilizers and sedatives, anti-inflammatory drugs, vitamins, drugs with anti-bacterial properties, etc. Since there is an increased interest in designing highly effective and controllable SERS-active substrates, a few newly developed substrates that could contribute to a deeper understanding and knowledge of the adsorption behavior of various types of molecules of pharmaceutical and medical interest are also presented.
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 Sample Preparation with Nanomaterials written by Chaudhery Mustansar Hussain and published by John Wiley & Sons. This book was released on 2021-04-30 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discover this timely, comprehensive, and up-to-date exploration of crucial aspects of the use of nanomaterials in analytical chemistry Sample Preparation with Nanomaterials: Next Generation Techniques for Sample Preparation delivers insightful and complete overview of recent progress in the use of nanomaterials in sample preparation. The book begins with an overview of special features of nanomaterials and their applications in analytical sciences. Important types of nanomaterials, like carbon nanotubes and magnetic particles, are reviewed and biological sample preparation and lab-on-a-chip systems are presented. The distinguished author places special emphasis on approaches that tend to green and reduce the cost of sample treatment processes. He also discusses the legal, economical, and toxicity aspects of nanomaterial samples. This book includes extensive reference material, like a complete list of manufacturers, that makes it invaluable for professionals in analytical chemistry. Sample Preparation with Nanomaterials offers considerations of the economic aspects of nanomaterials, as well as the assessment of their toxicity and risk. Readers will also benefit from the inclusion of: A thorough introduction to nanomaterials in the analytical sciences and special properties of nanomaterials for sample preparation An exploration of the mechanism of adsorption and desorption on nanomaterials, including carbon nanomaterials used as adsorbents Discussions of membrane applications of nanomaterials, surface enhanced raman spectroscopy, and the use of nanomaterials for biological sample preparation A treatment of magnetic nanomaterials, lab-on-a-chip nanomaterials, and toxicity and risk assessment of nanomaterials Perfect for analytical chemists, materials scientists, and process engineers, Sample Preparation with Nanomaterials: Next Generation Techniques for Sample Preparation will also earn a place in the libraries of analytical laboratories, universities, and companies who conduct research into nanomaterials and seek a one-stop resource for sample preparation.
Download or read book Improving Analytical Utility of Surface Enhanced Raman Spectroscopy Through Unique Lithographic Substrate Development written by Sabrina Marie Wells and published by . This book was released on 2012 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface enhanced Raman spectroscopy (SERS) has the potential to be a useful analytical technique due to large signal enhancements. Unfortunately, SERS has several drawbacks, including a lack of reproducibility, which inhibits it from being a practical option. These large signals often arise from "hot spots" of extremely high enhancement on nanofeatured metallic substrates, the most common being comprised of aggregated silver colloid. It is difficult to reproducibly create these hot spots due to the randomness of the colloid substrates. However, through controlled substrate fabrication, many problems associated with SERS analysis can be overcome. Electron beam lithography (EBL) combined with reactive-ion etching (RIE) was used to fabricate a wide variety of aggregate-like structures that allow for methodically surveying the system to determine if areas of high enhancement are present. Any well performing areas were then recreated consistently to produce areas of similar enhancement. While the aforementioned "combinatorial" approach has its advantages, simple structures are often easier to fabricate and theoretically model. As such, a single structure consisting of a metal disc on a silicon pillar was created. A variety of tests were performed on these structures to determine the overall utility of the simple pillar system. The system was found to possess extremely high enhancement, making it an ideal system to both theoretically model and test experimentally. The system also has strong enough overall signal to allow for potential analytical implications. Studies were also conducted to determine the feasibility of using a strong enhancing silicon nanopillar system to make analytical measurements without a metal surface present. A special fabrication process using EBL and RIE was used to created tall, high aspect ratio pillars of known diameters. These nanopillars were then observed to exhibit special optical properties not seen in bulk silicon. Aside from modest Raman enhancement, these structures also demonstrated the ability to enhance the signal of specific analytes similar to SERS. Surface enhanced fluorescence (SEF) was also observed for different analytes, allowing for a variety of potential analytical areas.
Download or read book A New Method for In situ Characterization of Important Actinides and Technetium Compounds Via Fiberoptic Surface Enhanced Raman Spectroscopy SERS written by and published by . This book was released on 2004 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project serves to fill information gap through the development of a novel surface-enhanced Raman scattering (SERS) spectroscopy to selectively and sensitively monitor and characterize the chemical speciation of radionuclides at trace levels. The SERS technique permits both of these measurements to be made simultaneously, and results in significant improvement over current methods in reducing time of analysis, cost, and sample manipulation. Our overall goal is (a) to develop a scientific basis for this new methodology to detect radionuclides via SERS and (b) to rationally synthesize and evaluate novel sol-gel based SERS substrates tailored to sensitively detect and characterize inorganic radionuclides such as TcO4−, actinyl ions (e.g. UO2{sup 2+}, NpO2, and PuO2{sup 2+}) and other chemical compounds of interest.
Download or read book Synthesis and Application of Colloidal Substrates for In solution Surface Enhanced Raman Scattering written by Casey John Rusin and published by . This book was released on 2020 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface-enhanced Raman scattering (SERS) has evolved into a powerful analytical measurement technique with the potential for single molecule detection. The technological advancement of handheld Raman instrumentation is powering the development of SERS applications in a variety of industries. Moreover, it is driving the movement from laboratory-based analyses to on-site/remote analyses. As a result, a main research component from this movement is to develop compatible SERS substrates. While the market is dominated by solid-based substrates, solution-based substrates do offer some benefits. These could include low production costs, high scalability, competitive reproducibility and shorter analysis times. The primary focus of the work in this thesis is to develop solution-based SERS substrates and explore their usage for in-solution measurements. This work highlights the development of three different types of solution-based substrates. The first substrate involves the synthesis and optimization of gold nanostars as a colloidal SERS substrate. The SERS performance is investigated and optimized using different Good's buffers, examining the buffer to gold salt concentration ratio and the use of an aggregating agent. In short, the results indicated that gold nanostars with smaller branches provided larger enhancement than those with larger branches, and this has been attributed to the Raman probe surface coverage on the nanostars rather than an electromagnetic effect. A SERS assay is also developed to quantitate methimazole in urine using a handheld Raman spectrometer. The second and third solution-based substrates are metal decorated cellulose nanofibers, also known as plasmonic cellulose nanofibers. These chapters focus on the growth of silver and gold nanoparticles onto oxidized cellulose nanofibers, and are used as a water dispersible substrate. In the development of plasmonic cellulose nanofibers, the cellulose nanofibers have two important roles: (1) to act as a dispersant in water and (2) act as a support for metallic nanoparticles. For both substrates, centrifugation played a key role in producing significant signal enhancement. Cellulose nanofibers decorated with silver nanoparticles were used for in-solution measurements of malachite green, while cellulose nanofibers decorated with gold nanoparticles were used for in-solution measurements of methimazole. Moreover, an assay is developed to quantitate methimazole in synthetic urine with cellulose nanofibers decorated with gold nanoparticles. Measurements using plasmonic cellulose nanofibers are taken with a Raman microscope, however, examples are shown to highlight the capability of remote analysis by coupling the substrates with a handheld Raman spectrometer. This work concludes with a comparative study between solid- and solution-based substrates. Using cellulose nanofibers decorated with gold nanoparticles, membrane- and glass- based SERS substrate are developed. This work discusses the benefits and challenges of solid- and solution-based substrates in terms of substrate development, measurement versatility and reproducibility. The primary contribution of this work is the development of multiple solution-based SERS substrates for in-solution measurements.
Download or read book Raman Spectroscopy and Instrumentation for Monitoring Soil Carbon Systems written by D. L. Stokes and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work describes developments in the application of Raman scattering and surface-enhanced Raman scattering (SERS) towards the assessment/characterization of carbon in soil. In the past, the nonspecific total carbon mass content of soil samples has generally been determined through mass loss techniques and elemental analysis. However, because of the concern over CO{sub 2} buildup in the atmosphere and its possible role in the ''Greenhouse Effect, '' there is a need for better-defined models of global cycling of carbon. As a means towards this end, there is a need to know more about the structure and functionality of organic materials in soil. Raman spectroscopy may therefore prove to be an exceptional tool in soil carbon analysis. Based on vibrational transitions of irradiated molecules, it provides structural information that is often suitable for sample identification. Furthermore, Raman scattering yields very fine spectral features which offer the potential for multicomponent sample analysis with minimal or no sample pretreatment. Although the intensity of Raman scattering is generally extremely low, the surface-enhanced Raman scattering (SERS) effect can greatly enhance Raman signals (10{sup 6}-10{sup 8} range) through the adsorption of compounds on specially roughened metal surfaces. In our laboratory, we have investigated copper, gold and silver as possible substrate metals in the fabrication of SERS substrates. These substrates have included metal-coated microparticles, metal island films, and redox-roughened metal foils. We have evaluated several laser excitation sources spanning the 515-785 nm range for both Raman and SERS analysis. For this particular study, we have selected fulvic and humic acids as models for establishing the feasibility of using Raman and SERS in soil carbon analysis. Our studies thus far have demonstrated that copper substrates perform best in the SERS detection of humic and fulvic acids, particularly when coupled to electrochemical processes that enhance adsorption of specific compounds. This effect not only yields a stronger signal, but can also impart selectivity in the analysis of complex samples such as soil.
Download or read book Characterization and Optimization of Novel Nanostructured Metallic Substrates for Surface Enhanced Raman Spectroscopy written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface enhanced Raman spectroscopy (SERS) is a highly sensitive technique for quantifying trace amounts of analyte adsorbed at a roughened metal surface. We have shown that novel gold nanostructured films, simply fabricated using gold nanoparticles and latex microspheres, can be used as highly sensitive SERS substrates. The films are templated by layers of colloidal crystals and display long ranged ordered regions, and porosity on two length scales that results in high surface area. By integrating these substrates into a flow chamber we have obtained consistent reproducible data and demonstrated the quantitative detection of sodium cyanide in the concentration range from 5 to 500 ppb, with detection significantly enhanced by lowering the pH after cyanide adsorption. We have found that the optimum size of the latex microspheres is approximately equal to the wavelength of the laser. Finally, the SERS activity of the gold substrates coated with silver nanoparticles was investigated using methyl phosphonic acid (MPA). Detection of MPA was dependent on the time between substrate coating and the SERS measurement. These studies show that novel materials formed by simple wet chemistry techniques can be used efficiently in practical devices for the detection of chemical agents.
Download or read book Surface Enhanced Raman Scattering written by Katrin Kneipp and published by Springer Science & Business Media. This book was released on 2006-06-21 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: Almost 30 years after the first reports on surface-enhanced Raman signals, the phenomenon of surface-enhanced Raman scattering (SERS) is now well established. SERS gained particular interest after single-molecule Raman spectroscopy had been demonstrated. This book summarizes and discusses present theoretical approaches that explain the phenomenon of SERS and reports on new and exciting experiments and applications of the fascinating spectroscopic effect.
Download or read book Determining the Electronic Properties of Surface Enhanced Raman Spectroscopy Substrates written by Liam David Whelan and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface Enhanced Raman Spectroscopy (SERS) is an ultra-sensitive technique for optical detection of target analytes. Our work focuses on detecting oil in water using SERS, with this thesis using phenanthrene as a model compound. SERS is a technique which takes advantage of the optical properties of metal substrates to greatly increase the intensities of adsorbed analytes' vibrational modes. The rapid development of novel materials as SERS active substrates requires an efficient screening method. SERS Enhancement Factor (EF) does correlate somewhat with surface morphology and UV-Vis absorption, however we present a technique which shows an even stronger correlation and is ultimately a better screening tool: Kelvin Probe Force Microscopy (KPFM). This technique maps the electronic properties of a substrate to its surface morphology. This thesis covers two classes of SERS substrates: annealed bimetallic systems and nanosphere patterned mono- and bimetallic systems. The ability to directly map the electronic properties of a substrate to its morphological properties is of critical importance in determining a key link between the macroscale SERS sensor response and the microscale substrate structure. Our major findings indicate that when Au/Cr nanostructured films' work function is near the calculated and experimental values for the HOMO-LUMO gap of the target analyte, phenanthrene, the observed SERS intensity reaches a maximum.
Download or read book Study of SERS for the Detection of Drugs of Abuse written by Sarah Louise Lamping and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the use of Surface Enhanced Raman Spectroscopy (SERS) for the detection of illicit drugs in oral fluid using metal enhancement mechanisms was undertaken. Initial work investigated ecstasy tablet composition using Raman to identify what drugs and excipients might be present in oral fluid samples obtained from users. Overall, it is possible to identify the presence of phenethylamines and excipients in the seized tablets but not categorically distinguish between the phenethylamine derivative(s) especially when in a mixture. Comparison of the overall batch average peak positions and peak responses of the phenethylamine derivatives and excipients shows variability across the batches and reveals trends within the sub-batches. The Raman spectra appear to reflect the findings of the GUMS analysis tentatively, implying this technique could be used for initial intelligence gathering applications whilst confirmatory analysis results are awaited. Initial SERS research focused on achieving enhancement of aqueous drug solutions with silver and gold colloid. Overall a lack of reproducibility was observed. Therefore, alternative SERS enhancement mechanisms were sought. Ag/Ti02 substrates demonstrated low limits of detection and the possibility of detecting SERS enhancement of aqueous amphetamine solution at levels below 8x10−2 M. The work also showed that cotton swabs for sample application onto the surface of the substrate are a viable practical option for both experimental and field analysis. Successful detection of methadone and buprenorphine, used to treat heroin addiction, was achieved with Ag/Ti02 substrates at concentrations associated with therapeutic use, representing lower concentration drugs. The detection of MDMA in oral fluid following ecstasy use, not only showed promise for the detection of illicit drugs, but did so at the analytical cut-off concentration detailed in the draft type approval specification for roadside drug screening devices. This work confirms that SERS has a role for drug detection in oral fluid samples.
