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Full-Text Articles in Materials Chemistry

Sers For The Detection Of Trace Materials, Omari Kirkland Jun 2023

Sers For The Detection Of Trace Materials, Omari Kirkland

Dissertations, Theses, and Capstone Projects

In this dissertation are presented three projects that contribute to the body of research on SERS in the forensic, heritage, and semiconductor fields. The first project, Charge-Transfer mapping on GaN/Ag, a silver-decorated nanopillar semiconductor substrate fabricated from the GaN is used with the Raman probe Rhodamine 6 G (R6G) to map the effect of the nanofeatures on the CT resonance. The second project, in collaboration with Marco Leona from the Metropolitan Museum of Art, explores the use of AgNIFs to identify colorants used on textile fiber samples from four 19th century works of Japanese art. The final project analyzes the …


Real-Time Monitoring Of Paraquat Photodegradation Using Colloidal Gold Surface Enhanced Raman Spectroscopy, Nathan Wilson May 2022

Real-Time Monitoring Of Paraquat Photodegradation Using Colloidal Gold Surface Enhanced Raman Spectroscopy, Nathan Wilson

Masters Theses & Specialist Projects

Monitoring chemical reactions in aqueous solution is a challenge because most instrumental techniques either are not suited for the rapid timescales, are not sensitive enough to detect products at low concentrations, or do not have sufficient structure-to-spectrum relationships. Raman spectroscopy is a promising method to monitor reactions, as it is fast, dependent on chemical structure, and has little interference from water. However, Raman scattering is generally very weak. Surface-enhanced Raman spectroscopy (SERS) improves the signal strength of Raman spectroscopy by using a metal surface plasmon, or oscillation of the surface’s electrons, to allow for highly selective and sensitive detection and …


Surface Enhanced Raman Spectroscopy (Sers) As A Nanoscale Adsorption Phenomenon: Development Of Tailored Nanomaterials For Applications In Drug Detection, Chiara Deriu Nov 2020

Surface Enhanced Raman Spectroscopy (Sers) As A Nanoscale Adsorption Phenomenon: Development Of Tailored Nanomaterials For Applications In Drug Detection, Chiara Deriu

FIU Electronic Theses and Dissertations

Surface Enhanced Raman Spectroscopy (SERS) is an analytical technique in which nanostructured substrates amplify the inherently weak Raman signal of an adsorbed species by several orders of magnitude, enabling the detection of trace compounds, up to the single molecule level. While this may be an exceptional tool for any analytical scientist, SERS is at present relegated to the role of academic sensation, and is underutilized in everyday analytical practice. The SERS community is increasingly attributing this setback to a poor understanding of nanoscale surfaces and their chemical environment; since molecular adsorption at the nanostructured surface enables SERS detection, uncertainty about …


Using Surface-Enhanced Raman Scattering Of Gold Nanostars For Encoding Molecular Information, Samantha E. Curry Apr 2020

Using Surface-Enhanced Raman Scattering Of Gold Nanostars For Encoding Molecular Information, Samantha E. Curry

Honors Thesis

Increases in the selling of illicit goods warrant a subsequent need for even more sophisticated methods to prevent counterfeit products from being sold. Surface-enhanced Raman spectroscopy (SERS) has the potential to be a powerful tool to thwart counterfeiters because the unique security tags fabricated with this method are difficult to reproduce without knowing the “secret” recipes used in their preparation. In this work, gold nanostars are used as SERS active substrates since their branched structure allows for strong coupling between the light and plasmonic nanoparticles. As a result, Raman signals of trace amount of chemicals can be easily detected. The …


Raman And Surface Enhanced Raman Spectroscopy For Forensic Analysis: Case Studies On The Identification Of Illicit Substances And Artist Pigments, Abed Haddad May 2019

Raman And Surface Enhanced Raman Spectroscopy For Forensic Analysis: Case Studies On The Identification Of Illicit Substances And Artist Pigments, Abed Haddad

Dissertations, Theses, and Capstone Projects

Raman spectroscopy is an effective tool for detecting trace amounts of material by fingerprint-like vibrational spectra. At times, the weak intensity of Raman scattering can make it difficult to distinguish trace materials. This shortcoming is addressed by surface‐enhanced Raman spectroscopy (SERS), which produces strong signal enhancements when target compounds are near metal nanoparticles. For the first part of this thesis, the identification of fentanyl and carfentanil, main culprits in the opioid epidemic, was done using normal Raman and the SERS spectroscopy. As an aid in the assignment of the spectral lines, a computational model was built using Density Functional Theory …


Use Of Surface Enhanced Raman Spectroscopy For The Detection Of Bioactive Lipids, Christopher M. Ohlhaver Jan 2018

Use Of Surface Enhanced Raman Spectroscopy For The Detection Of Bioactive Lipids, Christopher M. Ohlhaver

Theses and Dissertations

The detection and analysis of lipids in biological matrices for clinical applications poses many challenges, but rapid and reliable detection will prove invaluable for clinical diagnosis. Herein, we report the application of drop-casted Ag nanoplatelets as surface enhanced Raman scattering (SERS) substrates for qualitative detection of 20-hydroxyeicosatetraenoic acid (20-HETE), which is a potential biomarker for diagnosis of hypertensive disorders. Biomarker peaks of 20-HETE can be reliably detected and differentiated from those of the structurally similar lipids (arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid) commonly found in human blood, even 1 pM concentrations. Additionally, one study mixed 20-HETE with three structurally …


Sol-Gel Assembly Of Metal Nanostructures Into Metallic Gel Frameworks And Their Applications, Xiaonan Gao Jan 2016

Sol-Gel Assembly Of Metal Nanostructures Into Metallic Gel Frameworks And Their Applications, Xiaonan Gao

Theses and Dissertations

The advent of nanoscience and nanotechnology has sparked many research forefronts in the creation of materials with control over size, shape, composition, and surface properties.1,2 However, for most of the applications, nanoscale materials need to be assembled into functional nanostructures that exhibit useful and controllable physical properties. Therefore, numerous efforts on the assembly of nanoparticles (NPs) using organic ligands, polymers and polyelectrolytes have been reported.3,4 However, the interactions between NPs are mediated by intervening ligands, which are detrimental to charge transport and limit the thermal stability. Hence, developing a new method to produce solid …


Improving Analytical Utility Of Surface Enhanced Raman Spectroscopy Through Unique Lithographic Substrate Development, Sabrina Marie Wells May 2012

Improving Analytical Utility Of Surface Enhanced Raman Spectroscopy Through Unique Lithographic Substrate Development, Sabrina Marie Wells

Doctoral Dissertations

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 …


Electrooxidation Of Carbon Monoxide On Pd Thin Film-Coated Au Electrodes:Film Thickness Dependence, Yuqing Yang, Shouzhong Zou Aug 2010

Electrooxidation Of Carbon Monoxide On Pd Thin Film-Coated Au Electrodes:Film Thickness Dependence, Yuqing Yang, Shouzhong Zou

Journal of Electrochemistry

The adsorption and electrooxidation of CO on Pd-coated Au electrodes were studied by cyclic voltammetry and surface-enhanced Raman spectroscopy (SERS) . It is found that CO oxidation activity is film thickness dependent. Cyclic voltammograms (CVs) showed that CO oxidation peak potential shifted positively with the increase of the Pd thickness. SERS showed a redshift of the C—O stretching frequency with increasing Pd film thickness. These observations were explained by the dband theory. The strain effect strengthens CO adsorption and stabilizes adsorbed CO,while the ligand effect weakens CO adsorption and eases its oxidation. The ligand effect overpowers the strain effect.


Preliminary Investigation Of Iron Protoporphyrin Sams On Platinum Electrodes By Surface Enhanced Vibrational Spectroscopies, Min Ma, Yao-Yue Yang, Han-Xuan Zhang, Wen-Bin Cai Aug 2010

Preliminary Investigation Of Iron Protoporphyrin Sams On Platinum Electrodes By Surface Enhanced Vibrational Spectroscopies, Min Ma, Yao-Yue Yang, Han-Xuan Zhang, Wen-Bin Cai

Journal of Electrochemistry

In situ SERS and ATR-SEIRAS were applied to investigate the electrochemical and structural properties of iron protoporphyrin IX (FePP) self-assembled monolayers (SAMs) on Pt electrodes in 0. 1 mol· L -1 HClO4. The potential dependent SERS spectra of the FePP SAM on a roughened Pt electrode with the enhancement factor of ca. 40 were acquired with the excitation line of 514 nm. Analyses of SERS data over the potential region from 0. 5 to -0. 3 V enabled to obtain potential dependent adsorption isotherms,from which the formal redox potential could be estimated to be ca. - 0. 2 V. Up-tilted …


Template Synthesis And Electrochemical Studies Of Ag_(Core)Au_(Shell) Nanowires, Li Ling, Ya-Xian Yuan, Min-Min Xu, Jian-Lin Yao, Ren-Ao Gu May 2007

Template Synthesis And Electrochemical Studies Of Ag_(Core)Au_(Shell) Nanowires, Li Ling, Ya-Xian Yuan, Min-Min Xu, Jian-Lin Yao, Ren-Ao Gu

Journal of Electrochemistry

Agcore Aushell nanowires with different thicknesses were prepared by combining template synthesis and chemical reduction method,and characterized by SEM and cyclic voltammetry(CV).The CV results revealed that the AgcoreAushell nanowires with pinhole were transferred to pinhole free structure after several potential scans.By using thiophenol(TP)and p-aminothiophenol(PATP)as probe,the surface enhanced Raman scattering(SERS)effect was investigated on the core-shell nanowires.The results indicated that AgcoreAushell nanowires could be served as a potential SERS substrate,and the difference in the spectral feature of PATP adsorbed onto Au and Ag nanowires enable us to diagnose the pinhole effect of core-shell nanowires by SERS.


Surface Enhanced Raman Spectroscopic Study Of Scn - Adsorbed At The Copper And Gold Nanowire Arrays, Jianlin A Yao, Guoping Pan, Kuanhong Xue, Yong Xie, Jing Tang, Bin Ren, Dongmei Sun, Bingwei Mao, Zhongqun Tian Nov 1999

Surface Enhanced Raman Spectroscopic Study Of Scn - Adsorbed At The Copper And Gold Nanowire Arrays, Jianlin A Yao, Guoping Pan, Kuanhong Xue, Yong Xie, Jing Tang, Bin Ren, Dongmei Sun, Bingwei Mao, Zhongqun Tian

Journal of Electrochemistry

Two_dimensional arrays of Cu and Au nanowires have been fabricated by template synthesis method, using the anodic aluminum oxidation films as the template. The morphology of the nanowire array was monitored by atomic force microscope (AFM) in the dissolution processes of the alumina film. Based on the probe molecule strategy, the spectral feature of SCN - adsorbed at the Cu and Au nanowires with different diameters has been investigated by surface enhanced Raman spectroscopy (SERS). The results reveal that the intensity of the SERS bands depends on the length of the exposed nanowires. The C≡N stretching vibration frequency (ν CN …