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 Surface Enhanced Raman Scattering SERS Substrates and Probes written by Srismrita Basu and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Characterization of Substrates for Surface enhanced Raman Scattering written by B. M. Atkinson and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spark Ablation written by Andreas Schmidt-Ott and published by CRC Press. This book was released on 2019-12-19 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spark ablation has been used worldwide for decades. However, in many fields, the special properties of nanoparticles, which come into play especially for sizes
Download or read book Nanostructured Substrates for Surface Enhanced Raman Scattering written by and published by . This book was released on 2004 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Detection of Molecular and Biomolecular Species by Surface Enhanced Raman Scattering Nanoengineered Substrates for SERS Detection written by and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our research has confirmed that the significant Raman enhancement from a nanoshell based substrate is generated by the electromagnetic enhancement of individual nanoshells, not aggregates (dimers, trimers, etc.). Unlike metal colloids and roughened surfaces, the significant Raman enhancements achieved are consistent across the substrate and are not related to "hot spots" associated with aggregate geometries. This will allow the reproducible manufacture of a substrate with superior enhancement for use in future target specific SERS applications. The Raman enhancement achieved this individual nanoshell" substrate equals or exceeds 10 exp 10, evaluated using direct comparison between the unenhanced and enhanced signal from the same molecule. It is important to note that when these enhancements are compared to those of Kneipp et a., who reported values of 10 exp 10, the nanoshell-based enhancement appears to be approximately 10 exp 15 using their analytical method. The enhancement factors demonstrated are consistent with reported enhancements factors necessary for single molecule detection. Nanoshell-based SERS substrates have been reproducibly manufactured and tested for stability under various conditions. The method of manufacturing will allow use with both dry and aqueous samples.
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 Generation and Optical Properties of Silver Surface Enhanced Raman Scattering Substrates written by Peter Christian Andersen and published by . This book was released on 2003 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plastic Substrates for Surface enhanced Raman Scattering written by Matthias Geissler and published by . This book was released on 2009 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 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 Development and Application in Surface Enhanced Raman Scattering Substrate written by 王懷賢 and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Silver Dendrite Based Three dimensional Surface Enhanced Raman Scattering SERS Substrates written by Sandesh Rajkumar Shelke and published by . This book was released on 2016 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three-dimensional (3D) hierarchical nanostructures have been considered as one of the most promising surface-enhanced Raman spectroscopy (SERS) substrates because it provides high-density hotspots along the three-dimension directions and high surface areas. In this thesis, we report the synthesis process to develop 3D SERS substrates in thin wall quartz capillary tube on Cu wire. These 3D SERS substrates consist of Ag dendrite, Au-Ag and Pd-Ag bimetallic nanostructures which was synthesized by employing simple galvanic replacement reactions (GRR). In this synthesis process Cu wire which is used as substrate was inserted in the thin walled quartz capillary tube and then AgNO3 was injected into the tube to form Ag dendrite on the Cu wire substrate. This pre-prepared dendrite was used to prepare bimetallic nanostructures of Au-Ag and Pd-Ag by injecting chlorauric acid (HAuCl4) and palladium chloride (PdCl4) into the tube, respectively. The GRR process leads to the replacement of Ag atoms by Au and Pd which causes corresponding morphological change of the underlying Ag dendrite. The GRR leaves pores where Ag is depleted. The morphological and compositional changes caused by GRR was analyzed by using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Two close metallic surfaces can enhance the electromagnetic (EM) field around molecules absorbed between them, which leads to extremely high SERS enhancement. These 3D SERS substrates was tested in detection of aqueous 4-Mercaptobenzoic Acid (4-MBA) solution with various concentrations. The fabricated substrate was employed to detect the 4-MBA solution to the detection limit down to 10-13 M and exhibits highenhanced performance. The results indicated that these 3D unique bimetallic nanostructures can amplify Raman signals for extremely low concentration molecules as compared to the Ag dendrite nanostructure substrates.
