Download or read book Surface enhanced Raman Spectroscopy Substrate for Arsenic Sensing in Groundwater written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A surface-enhanced Raman spectroscopy (SERS) substrate formed from a plurality of monolayers of polyhedral silver nanocrystals, wherein at least one of the monolayers has polyvinypyrrolidone (PVP) on its surface, and thereby configured for sensing arsenic is described. Highly active SERS substrates are formed by assembling high density monolayers of differently shaped silver nanocrystals onto a solid support. SERS detection is performed directly on this substrate by placing a droplet of the analyte solution onto the nanocrystal monolayer. Adsorbed polymer, polyvinypyrrolidone (PVP), on the surface of the nanoparticles facilitates the binding of both arsenate and arsenite near the silver surface, allowing for highly accurate and sensitive detection capabilities.
Download or read book Octadecylthiol modified Surface enhanced Raman Spectroscopy Substrates written by Keith T. Carron and published by . This book was released on 1992 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nanosensors written by Vinod Kumar Khanna and published by CRC Press. This book was released on 2021-02-25 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanosensors are innovative devices that exploit the unique properties exhibited by matter at the nanoscale. A growing and exciting field, nanosensors have recently spurred considerable research endeavors across the globe, driving a need for the development of new device concepts and engineering nanostructured materials with controlled properties. Nanosensors: Physical, Chemical, and Biological, Second Edition offers a panoramic view of the field and related nanotechnologies with extraordinary clarity and depth. Presenting an interdisciplinary approach, blending physics, chemistry and biology, this new edition is broad in scope and organised into six parts; beginning with the fundamentals before moving onto nanomaterials and nanofabrication technologies in the second part. The third and fourth parts provide a critical appraisal of physical nanosensors, and explore the chemical and biological categories of nanosensors. The fifth part sheds light on the emerging applications of nanosensors in the sectors of society, industry, and defense and details the cutting-edge applications of state-of-the-art nanosensors in environmental science, food technology, medical diagnostics, and biotechnology. The final part addresses self-powering and networking issues of nanosensors, and provides glimpses of future trends. This is an ideal reference for researchers and industry professionals engaged in the frontier areas of material science and semiconductor fabrication as well as graduate students in physics and engineering pursuing electrical engineering and electronics courses with a focus on nanoscience and nanotechnology. Key features: Provides an updated, all-encompassing exploration of contemporary nanosensors and highlights the exclusive nanoscale properties on which nanosensors are designed. Presents an accessible approach with a question-and-answer format to allow an easy grasp of the intricacies involved in the complex working mechanisms of devices. Contains clear, illustrative diagrams enabling the visualization of nanosensor operations, along with worked examples, end of chapter questions, and exhaustive up-to-date bibliographies appended to each chapter.
Download or read book Surface Enhanced Raman Scattering New Theoretical Approaches Materials and Strategies written by Ivano Alessandri and published by Frontiers Media SA. This book was released on 2020-03-25 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Surface Enhanced Raman Scattering Substrate for Sensitive Detection of Aqueous Contaminants written by Md. Shah Alam and published by . This book was released on 2018 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metal Nanoparticles and Clusters written by Francis Leonard Deepak and published by Springer. This book was released on 2017-11-17 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the continually expanding field of metal nanoparticles and clusters, in particular their size-dependent properties and quantum phenomena. The approaches to the organization of atoms that form clusters and nanoparticles have been advancing rapidly in recent times. These advancements are described through a combination of experimental and computational approaches and are covered in detail by the authors. Recent highlights of the various emerging properties and applications ranging from plasmonics to catalysis are showcased.
Download or read book Inorganic Pollutants in Water written by Pooja Devi and published by Elsevier. This book was released on 2020-03-18 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inorganic Pollutants in Water provides a clear understanding of inorganic pollutants and the challenges they cause in aquatic environments. The book explores the point of source, how they enter water, the effects they have, and their eventual detection and removal. Through a series of case studies, the authors explore the success of the detection and removal techniques they have developed. Users will find this to be a single platform of information on inorganic pollutants that is ideal for researchers, engineers and technologists working in the fields of environmental science, environmental engineering and chemical engineering/ sustainability. Through this text, the authors introduce new researchers to the problem of inorganic contaminants in water, while also presenting the current state-of-the-art in terms of research and technologies to tackle this problem. Presents existing solutions to pollution problems, along with their challenges Includes case studies that detail success stories, challenges and the implementation of these tools Provides solutions that are both economically and ecologically sustainable
Download or read book Substrates for Surface enhanced Raman Spectroscopy written by Muḥammad Ajmal K̲h̲ān and published by . This book was released on 2008 with total page 730 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Surface enhanced Raman Scattering written by Deepak Bhandari and published by . This book was released on 2011 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: To advance the capabilities of surface-enhanced Raman scattering (SERS), we developed a silver modied polypropylene filter (AgPPF) substrate which acts as a pseudo stationary phase in harvesting SERS signatures of so called "phytochemical estrogens" and other environmentally significant chemicals. To augment electron beam lithography (EBL) in SERS research, we also introduced an interesting nanotransfer printing (nTP) technique which could circumvent the low throughput and extremely high resolution (
Download or read book Ag Nano dendritic Three dimensional 3D Surface enhanced Raman Scattering SERS Substrate for In situ Liquid Media Detection written by Milind Mansing Pawar and published by . This book was released on 2019 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: Continuous monitoring of certain environmental pollutants, biological species, chemical species, and explosives are of utmost importance in recent times. Surface-enhanced Raman scattering (SERS) provides most promising option as it is a highly sensitive technique which allows for ultrasensitive detection of molecules and provides excellent structural information. To obtain rich results through Surface-enhanced Raman scattering, proper design of enhancing substrate plays vital role. Contemporary SERS substrates don't provide ease to detect liquid analytes for in-situ spectroscopy. Liquid media detection through SERS relies on highly statistical binding of analytes to SERS-sensitive hot spots. Moreover, it becomes extremely difficult to detect flowing liquid media in-situ with two dimensional substrates as very small volume of Liquid contact with substrates. Single crystal Ag dendrite structures possess high surface area along with narrow gaps and sharp edges. Compared with other nanostructures, the hierarchical nanostructures-dendritic Ag, consisting of multi-level branches can significantly promote the SERS enhancement and serve as effective SERS substrates with high sensitivity and reproducibility. Such complex nanostructures may provide a large amount of "hot spots" at the end of branches or the junctions of adjacent Ag branches. In addition, the large surface area of Ag dendrites can enhance the interaction between analytes and sensing substrates. Ag dendrites can easily be produced, by use of one of the simplest galvanic reactions, the reaction of AgNO3 with Cu. We have developed novel yet simple Surface-enhanced Raman scattering- active substrate having three-dimensional array of Ag-dendrites grown within square geometry capillary tube of borosilicate glass via such galvanic replacement reaction with inserted copper wire. Systematic study of growth mechanism of Ag-dendrites was carried out and complex nature of seemingly "simple" galvanic replacement reaction has been proposed. The resultant Ag dendrites were characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy and X-ray diffraction. Atime-dependent investigation on the growth mechanism of the Ag dendrites revealed that they develop through a particle-mediated growth process. The effect of the reactant concentrations on the morphology of the synthesized Ag dendrites was also studied. This study on Ag dendrite growth mechanisms are not only scientifically intriguing, but also technologically important. Novel Ag dendrite three-dimensional SERS substrate exhibits excellent sensitivity and a very good reproducibility. We have detected rhodamine 6G(R6G) with lowest concentration of 10-11 M in aqueous solution. These Ag dendrite nanostructured three-dimensional SERS substrates are proved as excellent in-situ liquid media Raman detection substrates due to availability of extensive hot spots. It has significant potential to be used as SERS substrates for fast and accurate detection of trace amount of organic contaminants in flowing liquid media.
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 Detection of Anionic Arsenic Species by Surface Enhanced Raman Spectroscopy written by Mary Lower and published by . This book was released on 2007 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 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 Nanocrystal Assembly for Botton up Plasmonic Materials written by Andrea Rae Tao and published by . This book was released on 2007 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
