We demonstrate ordered orientation of the hydration water at the surface of phospholipid bilayers by use of coherent anti-Stokes Raman scattering (CARS) microscopy, a highly sensitive vibrational imaging method recently developed. We investigated negatively charged POPS (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine) and neutral POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) multilamellar onions dispersed in deuterated dodecane. The imaging contrast based on the CARS signal from the H2O stretching vibration shows a clear dependence on the excitation field polarization. Our results provide direct experimental evidence that water molecules close to the phospholipid bilayer surface are ordered with the symmetry axis along the direction normal to the bilayer. Moreover, the amount of ordered water molecules depends on the lipid polar group. The spectral profile for the interlamellar water shows that the water molecules bound to the bilayer surface are less hydrogen-bonded and exhibit a ...
We report a mechanistic analysis of photodamage in coherent anti-Stokes Raman scattering (CARS) microscopy. Photodamage to the myelin sheath in spinal tissues is induced by using the point scan mode and is featured by myelin splitting and shockwaves with broadband emission. Our measurement of photodamage rate versus the excitation power reveals that both linear and nonlinear mechanisms are involved. Moreover, we show that vibrational absorption induced by coherent Raman processes significantly contributes to the nonlinear damage at high peak powers. For CARS imaging of cultured cells, the photodamage is characterized by plasma membrane blebbing and is dominated by a second order mechanism. Our study suggests that for dense samples such as the myelin sheath, CARS imaging induced photodamage can be minimized by using laser beams with relatively long near IR wavelengths and a repetition rate of a few MHz. For less dense samples such as cultured cells, laser pulses of higher repetition rates are ...
Coherent Anti-Stokes Raman Scattering (CARS)-microscopy has in recent years developed as a promising microscopical technique for label-free microscopy of living cells. We propose a new concept, spectral focusing, for highly efficient coherent anti-Stokes Raman scattering (CARS) microscopy. It allows optimal use of the excitation energy of femtosecond laser pulses in terms of generated CARS signal against a low background. This is accomplished by introducing a linear chirp in the excitation pulses. The temporal delaying of the excitation pulses can be used to record vibrational spectra of a sample. Despite the inherently broad spectral width of the excitation pulses, the technique enables resolution of spectral features 60 times narrower than the bandwidth of the probe light. First applications of this technique are exemplified with CARS of micron sized crystallites of sodium nitroprusside, a commonly used hypotensive agent ...
Nanoparticulate drug delivery is known to greatly improve the efficacy of pharmaceuticals and has found a wide range of applications with different administration methods including oral, intravenous, transcutaneous and ocular routes. However, the mechanisms by which these nanoparticles travel through, interact with, and modify tissues and how this relates to the improved drug performance are still unclear. These are critical questions that need to be answered to optimise the properties of future pharmaceuticals, dose rates and frequencies, and reduce potential side effects. Our ability to answer these questions is greatly hindered by the fact that there is currently no imaging modality available to directly visualise such small particles and the structure and function of the surrounding tissue, without the aid of contrast agents or highly invasive methods. Current imaging modalities derive image contrast of the nanoparticles and/or the surrounding tissues by means of external labels. We present ...
The rather thin outermost layer of the mammalian skin, stratum corneum (SC), is a complex biomembrane which separates the water rich inside of the body from the dry outside. The skin surface can be exposed to rather extreme variations in ambient conditions (e.g. water activity, temperature and pH), with potential effects on the barrier function. Increased understanding of how the barrier is affected by such changes is highly relevant for regulation of transdermal uptake of exogenous chemicals. In the present study we investigate the effect of hydration and the use of a well-known humectant, urea, on skin barrier ultrastructure by means of confocal Raman microspectroscopy. We also perform dynamic vapor sorption (DVS) microbalance measurements to examine the water uptake capacity of SC pretreated with urea. Based on novel Raman images, constructed from 20 spectral maps, we can distinguish large water inclusions within the skin membrane exceeding the size of fully hydrated corneocytes. We show that ...
Raman spectroscopy has numerous applications in the field of biology. One such application is the simultaneously measurement of the concentration of multiple biochemical components in low volume aqueous mixtures, for example, a single drop of blood serum. Over twenty years ago, it was shown for the first time that it was possible to estimate the concentration of glucose, urea, and lactic acid in mixture by combining Raman Spectroscopy with Partial Least Squares Regression analysis. This was followed by numerous contributions in the literature designed to increase the number of components and reduce the limits of concentration that could be simultaneously measured using Raman spectroscopy, by developing various optical architectures to maximise the signal to noise ratio. The aim of this paper is to demonstrate the potential of a confocal Raman microscopy system for multicomponent analysis for the case of physiologically relevant mixtures of glucose, urea, and lactic acid.. ...
Confocal Raman microscopy can identify particles in the 5-50 ?m range and can bridge the gap between micro-FT-IR and SEM-EDS analyses.
TY - JOUR. T1 - RESONANCE RAMAN SCATTERING STUDIES OF THE QUATERNARY STRUCTURE TRANSITION IN HEMOGLOBIN.. AU - Rousseau, D. L.. AU - Ondrias, M. R.. PY - 1983/1/1. Y1 - 1983/1/1. N2 - The oxygen-binding energy difference, the free energy of cooperativity, is a thermodynamic property, and its location can be determined from an examination of the deoxygenated and liganded proteins in both their high affinity and low affinity structures. An assessment of the energetic differences between these four steady-state protein structures should elucidate which interactions contain the free energy of cooperativity. Resonance Raman scattering plays a very important role in determining these interactions, since it is a very sensitive probe of the bonds involving the heme group. By examining the resonance Raman spectrum of the heme in both quaternary structures in the liganded and in the deoxy forms, it may in principle be determined if the free energy of cooperativity is localized in any heme-protein ...
TY - JOUR. T1 - Stimulated Raman scattering microscopy with long wavelengths for improved imaging depth. AU - Moester, Miriam J.B.. AU - Zada, Liron. AU - Fokker, Bart. AU - Ariese, Freek. AU - de Boer, Johannes F.. PY - 2019/9. Y1 - 2019/9. N2 - Stimulated Raman scattering (SRS) imaging is a fast, label-free, and sensitive technique to map the distribution of a vibrational species in a microscopy setting. It has great potential for applications in many fields, such as lipid imaging in biomedicine. However, depth penetration of the light into the sample is an issue with any light-based technique, especially with multiphoton techniques such as SRS. Using longer wavelengths allows deeper penetration into densely scattering materials, but applying wavelengths above 1,500 nm is challenging technically. We have built a flexible SRS microscope system capable of imaging with a combination of 1,064 nm and wavelengths over 1,500 nm, using the idler output of an optical parametric oscillator (OPO). For ...
TY - JOUR. T1 - Ultraviolet resonance Raman study of proline isomerization. AU - Harhay, Gregory P.. AU - Hudson, Bruce S.. PY - 1991/1/1. Y1 - 1991/1/1. N2 - The ultraviolet resonance Raman spectra of aqueous solutions of proline dipeptides obtained with 200- and 218-nm excitation at pH 1.5 and 6.5 are reported. The cis/trans isomer ratio for these dipeptides is known to depend on pH. The amide II′ like mode of the X-Pro peptide (imide) linkage at 1487 cm-1, involving predominantly the motions of the peptide carbon and nitrogen, is the most strongly enhanced band in the 200-250-nm region. We observe that this band does not shift appreciably with the change in isomer ratio associated with the change in pH. The same behavior is observed with the 1467-cm-1 band of aqueous polyproline, which has undergone a salt-induced isomerization. We conclude from these observations that contrary to earlier evidence the position of the amide II′ like band is not diagnostic for the isomeric state of the ...
TY - JOUR. T1 - Resonance Raman and surface-enhanced resonance Raman studies of polymer-modified electrodes which mimic heme enzymes. AU - Bell, Steven. AU - Devenney, M.D.. AU - Grimshaw, J.. AU - Hara, S.. AU - Rice, J.H.. AU - Trocha-Grimshaw, J.. PY - 1998. Y1 - 1998. N2 - Iron-5,10,15,20-tetraphenylporphyrin (FeTPP) has been incorporated into films of a coordinating hydrogel polymer support medium, poly(gamma-ethyl-L-glutamate) (PEG) functionalised with imidazole pendant arms (PEG-Im), and studied in situ on silver electrodes using a combination of both resonance Raman (RR) and surface-enhanced resonance Raman (SERR) spectroscopy. The SERR spectra give information on the portion of the film close to the electrode surface while RR spectra probe the. AB - Iron-5,10,15,20-tetraphenylporphyrin (FeTPP) has been incorporated into films of a coordinating hydrogel polymer support medium, poly(gamma-ethyl-L-glutamate) (PEG) functionalised with imidazole pendant arms (PEG-Im), and studied in situ on ...
The clinical development of therapeutic peptides has been restricted to peptides for non-CNS diseases and parenteral dosage forms due to the poor permeation of peptides across the gastrointestinal mucosa and the blood-brain barrier. Quaternary ammonium palmitoyl glycol chitosan (GCPQ) nanoparticles facilitate the brain delivery of orally administered peptides such as leucine(5)-enkephalin, and here we examine the mechanism of GCPQ facilitated oral peptide absorption and brain delivery. By analyzing the oral biodistribution of radiolabeled GCPQ nanoparticles, the oral biodistribution of the model peptide leucine(5)-enkephalin and coherent anti-Stokes Raman scattering microscopy tissue images after an oral dose of deuterated GCPQ nanoparticles, we have established a number of facts. Although 85-90% of orally administered GCPQ nanoparticles are not absorbed from the gastrointestinal tract, a peak level of 2-3% of the oral GCPQ dose is detected in the blood 30 min after dosing, and these GCPQ ...
1. Wang P, Liu B, Zhang DL, Belew, MY, Tissenbaum HA, Cheng JX*. Imaging Lipid Metabolism in Live Caenorhabditis elegans Using Fingerprint Vibrations. Angewandte Chemie International Edition. 2014; 53:11787-11792 (In press; Impact factor: 13.7). 2. Wang P, Li JJ, Wang P, Hu CR, Zhang DL, Sturek, M, Cheng JX*. Label-free quantitative imaging of cholesterol in intact tissues by hyperspectral stimulated Raman scattering microscopy. Angewandte Chemie International Edition. 2013; 52:13042-6 (Impact factor: 13.7). 3. Zhang D#, Wang P#, Slipchenko MN, Ben-Amotz D, Weiner AM, Cheng JX*. Quantitative vibrational imaging by hyperspectral stimulated Raman scattering microscopy and multivariate curve resolution analysis. Analytical chemistry. 2013;85(1):98-106. # Equal contribution first author. (Impact factor: 5.8). 4. Liao CS#, Slipchenko MN#, Wang P#, Hu CR, Li JJ, Oglesbee RA, Cheng JX*. Microsecond Scale Vibrational Spectroscopic Imaging by Multiplex Stimulated Raman Scattering Microscopy. Light: ...
The ordinary Raman scattering (ORS) spectra of virion protein of Granulosis Virus of Cabbage Butterfly Preris rapae (PrGV-VP) and their surface-enhanced Raman scattering (SERS) spectra adsorbed on the surface of silver colloid particles have been found that the Raman signal in the SERS spectra was enhanced by a factor of about 8 X 102. In ORS spectra of PrGV-VP, it indicates that PrGV-VP has a predominantly random-coil secondary structures. All tyrosine residues are exposed. And the PrGV-VP has a gauche-gauche- gauche configuration of the C-C-S-S-C-C linkage. In SERS spectra of PrGV-VP, the intensities of bands related to COO group and NH2 group vibrations are relatively strong. We interpret that the PrGV-VP are adsorbed on the Ag surface through both the carboxylate groups and the amino groups. The efficient enhancement of amide I and amide II vibrations are impeded, because the peptide groups of PrGV-VP are screened by the side-chains amino acid residues. The Raman enhancement of PrGV-VP has a ...
TY - JOUR. T1 - Raman difference studies of GDP and GTP binding to c-Harvey ras. AU - Wang, J. H.. AU - Xiao, D. G.. AU - Deng, H.. AU - Webb, Martin R.. AU - Callender, Robert. N1 - Copyright: Copyright 2007 Elsevier B.V., All rights reserved.. PY - 1998/8/4. Y1 - 1998/8/4. N2 - The vibrational spectra of phosphate modes for GDP and GTP bound to the c-Harvey p21(ras) protein have been determined using 18O isotope edited Raman difference spectroscopy. A number of the phosphate stretch frequencies are changed upon GDP/GTP binding to ras, and the results are analyzed by ab initio calculations and through the use of empirical relationships that relate bond orders and bond lengths to vibrational frequencies. Bound GDP is found to be strongly stabilized by its interactions, mostly electrostatic, with the active site Mg2+. Bound GTP also interacts with the active site Mg2+ via its β-phosphate group, as expected on the basis of crystallographic studies of bound GppNp. The angle between the nonbridging ...
There are many examples emphasizing the importance of particle analysis - be it in the API analysis of drugs, adhesives, recycling, electronics manufacturing, biomedical products and much more. Reverse engineering and the investigation of causes of defects in manufacturing processes can also require comprehensive particle analysis. One of the challenges in analyzing microparticles is the size of the particles themselves and the frequent incorporation of these contaminants into matrices. Particle defects can affect product quality, appearance and performance. The SENTERRA II confocal Raman microscope is a powerful tool for the analysis of microparticles without sample preparation and even within sample containers. In our application note, we have summarized some applications to give you an overview of the possibilities of confocal Raman microscopy. ...
This well established symposium will cover various aspects of modern Raman microscopy and detail the advantages of confocal Raman imaging and its applications. Scientific talks from distinguished speakers in academia and industry, the contributed talk and poster sessions, and the instrument demonstration will give the participants a deeper understanding of confocal Raman imaging.
The identification of normal and cancer breast tissue of rats was investigated using high-frequency (HF) FT-Raman spectroscopy with a near-infrared excitation source on in vivo and ex vivo measurements. Significant differences in the Raman intensities of prominent Raman bands of lipids and proteins structures (2,800-3,100 cm(-1)) as well as in the broad band of water (3,100-3,550 cm(-1)) were observed in mean normal and cancer tissue spectra. The multivariate statistical analysis methods of principal components analysis (PCA) and linear discriminant analysis (LDA) were performed on all high-frequency Raman spectra of normal and cancer tissues. LDA results with the leave-one-out cross-validation option yielded a discrimination accuracy of 77.2, 83.3, and 100% for in vivo transcutaneous, in vivo skin-removed, and ex vivo biopsy HF Raman spectra. Despite the lower discrimination value for the in vivo transcutaneous measurements, which could be explained by the breathing movement and skin ...
Confocal Raman microscopy is a high-resolution imaging technique that is widely used for the characterization of materials and specimens in terms of thei...
TY - GEN. T1 - Functionalized bio-nanoparticles in immunosensing using surface-enhanced raman scattering methods. AU - Lin, Chi Chang. AU - Yu, Chen Yuan. AU - Yang, Ying Mei. AU - Chen, Yan Fu. AU - Chang, Hsien Chang. PY - 2009/10/12. Y1 - 2009/10/12. N2 - An unique, sensitive, and highly specific immunoassay system using gold nanoparticles and Surface-Enhanced Raman Spectroscopy (SERS) is described. To demonstrate the analytical capabilities of the new technique, Raman reporter (DTNB) that is coimmobilized with biospecific anti-protein A on gold nanoparticles (AuNP). Anti-protein A-AuNP-DTNB, which combing both electromagnetic field and chemical enhancement, was used to exploits the SERS-derived signal. A dynamic range of 2-3 orders of magnitude and 1-10 pg/mL of detection limitation of protein A were achieved. The results indicated this new technique could be used in clinical diagnostic applications with fast, high sensitivity and highthroughput screening of antibodies.. AB - An unique, ...
Dr. Matthias Meier (IMTEK, University of Freiburg) Raman microscopy is a powerful optical technology able to insight into the organic and inorganic chemical composition of living cells. By providing specific information with high spatial resolution about vibrational energy levels of chemical bonds and molecules, Raman microscopy can fingerprint metabolic states of cells. On the other hand microfluidic large-scale integration technology has demonstrate to control precisely the chemical microenvironment of hundreds of cell cultures in parallel with over weeks. In this funded BIOSS project we aim to couple microfluidic chip technology and raman microscopy to study lipid signaling between and in primary human adipocytes. Lipid droplets within adipocytes are the largest energy reservoir in the human body. External hormone, and nutrient availability tightly regulate the build-up (lipogenesis) and break down (lipolysis) of the lipid droplets. Disruption of the regulatory signal network controlling ...
A great deal of effort has been focused on exploring the underlying molecular mechanism of osteoarthritis (OA) especially at the cellular level. We report a confocal Raman spectroscopic investigation on human osteoarthritic chondrocytes. The objective of this investigation is to identify molecular features and the stage of OA based on the spectral signatures corresponding to bio-molecular changes at the cellular level in chondrocytes. In this study, we isolated chondrocytes from human osteoarthritic cartilage and acquired Raman spectra from single cells. Major spectral differences between the cells obtained from different International Cartilage Repair Society (ICRS) grades of osteoarthritic cartilage were identified. During progression of OA, a decrease in protein content and an increase in cell death were observed from the vibrational spectra. Principal component analysis and subsequent cross-validation was able to associate osteoarthritic chondrocytes to ICRS Grade I, II and III with ...
HORIBA Scientific, the global leader in Raman spectroscopy systems and solutions, announces its newest Raman instrument. The AnywhereRaman instrument is a self-contained product that combines a spectrometer, a laser, a ball probe and an acquisition computer all in one instrument, to easily obtain high quality Raman measurements without the need for multiple instrumentation or processes.. HORIBAs new Raman product is designed for both portability and ease of use. It can go from being unpacked and set up, to first Raman measurements in under 20 minutes. These high quality Raman measurements can be obtained by operators with minimal training or experience.. The ball probe with TouchRaman™ immersion technology lets users simply touch the sample, and acquire data. The results are high-quality, reproducible measurements. Its excitation wavelength is 785 nm, with a spectral range of 150- 3150 cm-1.. The all-in-one AnywhereRaman unit is just 3.0 (H) x 9.8 (W) x 9.8 (D), and offers Class 3B laser ...
Methods: Twenty healthy subjects and 20 cancer patients undergoing chemotherapy were included. Measurement time points in cancer patients were before the first cycle of chemotherapy (Tbase) and immediately after intravenous application of the chemotherapy (T1). Healthy subjects were measured once without any further intervention. Measurements were conducted using an individually manufactured system consisting of a handheld probe and a wavelength-tunable diode laser-based 488 nm SHG light source. Hereby, changes in both skin fluorescence and shifted excitation resonance Raman difference spectroscopy (SERRDS) carotenoid signals were assessed ...
Stimulated Raman scattering (SRS) microscopy allows label-free chemical imaging based on vibrational spectroscopy. Narrowband excitation with picosecond lasers creates the highest signal levels and enables imaging speeds up to video-rate, but it sacrifices chemical specificity in samples with overlapping bands compared to broadband (multiplex) excitation. We develop a rapidly tunable picosecond optical parametric oscillator with an electro-optical tunable Lyot filter, and demonstrate multicolor SRS microscopy with synchronized line-by-line wavelength tuning to avoid spectral artifacts due to sample movement. We show sensitive imaging of three different kinds of polymer beads and live HeLa cells with moving intracellular lipid droplets.. © 2013 Optical Society of America. Full Article , PDF Article ...
Scanning electron microscopy with energy dispersive X-ray spectrometry (SEMEDS) and Fourier-transform infrared microspectrophotometry (micro-FT-IR) have been widely demonstrated as complementary analytical tools for the identification of complex mixtures and unknown materials. However, there is a gap between the information provided by these two techniques. ...
We believe that these imaging modalities have many potential medical applications for corneal/ocular surface imaging when the technology is further developed. Chronic topical glaucoma therapy has been associated with corneal damage characterized by the loss of certain corneal cell types as well as invasion of inflammatory cells. 48,49 CARS/TPAF would allow us to observe the number and type of corneal epithelial cells, which could determine the progression of corneal surface disease to better aid physician treatment. CARS/TPAF also has application in the area of corneal surgery, since this technology could be used to observe cell number and metabolic state (NAD[P]H level) at the site of a healing wound. Furthermore, CARS/TPAF can image at the level of the corneal endothelium to monitor cell health before and after cataract surgery. A combined CARS/TPAF system has recently been used to show the differences in lipid structures between in healthy and psoriasis-affected human skin. 50 By the same ...
Synthesis of new proteins, a key step in the central dogma of molecular biology, has been a major biological process by which cells respond rapidly to environmental cues in both physiological and pathological conditions. However, the selective visualization of a newly synthesized proteome in living systems with subcellular resolution has proven to be rather challenging, despite the extensive efforts along the lines of fluorescence staining, autoradiography, and mass spectrometry. Herein, we report an imaging technique to visualize nascent proteins by harnessing the emerging stimulated Raman scattering (SRS) microscopy coupled with metabolic incorporation of deuterium-labeled amino acids. As a first demonstration, we imaged newly synthesized proteins in live mammalian cells with high spatial-temporal resolution without fixation or staining. Subcellular compartments with fast protein turnover in HeLa and HEK293T cells, and newly grown neurites in differentiating neuron-like N2A cells, are clearly ...
We present a microscopic theory of quantum-size effects in surface-enhanced Raman scattering (SERS) from molecules adsorbed on small metal nanoparticles. In noble-metal nanoparticles, the confining potential has different effect on s-band and d-band electrons. Namely, the spillout of delocalized sp-electrons beyond the classical nanoparticle boundary results in an incomplete embedding of s-electron distribution in the background of localized d-electrons whose density profile follows more closely the classical shape. We demonstrate that a reduction of d-electron screening in the surface layer leads to the enhancement of the surface plasmon local field acting on a molecule located in a close proximity to metal surface. Our numerical calculations of Raman enhancement factor, performed using time-dependent local density approximation, show additional enhancement of the Raman signal which becomes more pronounced for small nanoparticles due to the larger ratio of surface layer to overall nanoparticle size.
Resonance Raman spectra of polymer chains in the single crystals of the diacetylenes FBS (2,4-hexadiynylene-di-p-fluorobenzene sulfonate), TS/FBS [6-(p-toluenesulfonyloxy)-2,4-p-fluorobenzene sulfonate] and TS6 (2,4-hexadiynylene-di-p-toluene sulfonate) are described theoretically by means of a Franckâ€Condon model, which considers a chain length dependence. The electronic transition energies and matrix elements are calculated by means of a linear-combination-of-atomic-orbitalsâ€molecular-orbital method calculation in the Hückel approach. We are able to describe the Raman excitation profiles as well as the Raman band profiles for two Raman active modes, i.e., the C+C-, and the C 3/4 C-stretching vibrations of the polymer chains. The model also contains a description of a side group vibrational mode which is enhanced by Fermi resonance with the C=C-stretching vibration. Observed Raman excitation profiles can be well simulated by these calculations. An evaluation of the parameters shows ...
In addition, confocal measurements can improve the rejection of stray light and reduce fluorescence interference. Not all confocal Raman microscopy designs are the same. Traditional confocal Raman microscopes, shown schematically in Figure 1(b), utilize a pinhole aperture placed in front of the spectrograph entrance slit. The Raman light is focused onto the pinhole and the diverging beam after the pinhole is then refocused onto the entrance slit of the spectrograph. Different pinhole apertures can be used to control the degree of confocality, while the entrance slit is used to control the spectral resolution of the spectrometer. While this true confocal configuration provides independent control of spatial and spectral resolutions, it is very difficult to align and to maintain optimum performance. This is because the beam is focused twice through two very small apertures. In practice, independent control of the two apertures offers little value. Typical slit widths must be less than 100 um to ...
A Raman spectrometry apparatus that is capable of measuring and compensating for variabilities in the apparatus comprises a source of substantially monochromatic radiation, means for simultaneously interfacing the radiation with a sample and a reference material, means for simultaneously acquiring at more than one wavelength a convolved Raman spectrum of the sample and a convolved spectrum of the reference material, and means for determining the convolution function of the convolved spectra and applying the convolution function to adjust the convolved Raman spectrum of the sample to produce thereby the standard Raman spectrum of the sample. A method for obtaining the standard Raman spectrum of a sample comprises: (a) simultaneously irradiating the sample and a reference material with a substantially monochromatic radiation source; (b) simultaneously acquiring at more than one wavelength a convolved Raman spectrum of the sample and a convolved spectrum of the reference material; (c) choosing the standard
Metabolic fingerprinting provides valuable information on the physiopathological states of cells and tissues. Traditional imaging mass spectrometry and magnetic resonance imaging are unable to probe the spatial-temporal dynamics of metabolites at the subcellular level due to either lack of spatial r …
As a superb tool to visualize and study the spatial-temporal distribution of chemicals, Raman microscopy has made a big impact in many disciplines of science. While label-free imaging has been the prevailing strategy in Raman microscopy, recent development and applications of vibrational/Raman tags, particul Recent Review Articles
Elkordy, Amal, Forbes, Robert T and Barry, Brian W (2008) Study of protein conformational stability and integrity using calorimetry and FT-Raman spectroscopy correlated with enzymatic activity. European Journal of Pharmaceutical Sciences, 33 (2). pp. 177-190. ISSN 0928-0987 ...
A thermoelectrically cooled surface-enhanced Raman Spectroscopy (TEC-SERS) fiber optic probe for real-time and in-situ monitoring of volatile organic compounds in gas, liquid, and soil environments. The TEC-SERS probe comprises a sample chamber for receiving a gas sample and a fiber optic Raman probe. The sample chamber comprises an inlet having a semipermeable membrane for separating moisture from the gas sample, a SERS substrate mounted on a thermoelectric cooler, a mass flow device for providing airflow, and an output port. The fiber optic Raman probe is operably coupled to a transparent window in the sample chamber for directing an optical excitation signal to irradiate the SERS substrate and for receiving a SERS optical signal from analytes from the gas sample that are in contact with the SERS substrate.
In situ surface-enhanced Raman scattering studies of the nitrosyl adduct of hemin adsorbed roughened silver surfaces in aqueous electrolytes
TY - JOUR. T1 - Present and Future of Surface-Enhanced Raman Scattering. AU - Langer, Judith. AU - Jimenez De Aberasturi, Dorleta. AU - Aizpurua, Javier. AU - Alvarez-Puebla, Ramon A.. AU - Auguié, Baptiste. AU - Baumberg, Jeremy J.. AU - Bazan, Guillermo C.. AU - Bell, Steven E.J.. AU - Boisen, Anja. AU - Brolo, Alexandre G.. AU - Choo, Jaebum. AU - Cialla-May, Dana. AU - Deckert, Volker. AU - Fabris, Laura. AU - Faulds, Karen. AU - García De Abajo, F. Javier. AU - Goodacre, Royston. AU - Graham, Duncan. AU - Haes, Amanda J.. AU - Haynes, Christy L.. AU - Huck, Christian. AU - Itoh, Tamitake. AU - Käll, Mikael. AU - Kneipp, Janina. AU - Kotov, Nicholas A.. AU - Kuang, Hua. AU - Le Ru, Eric C.. AU - Lee, Hiang Kwee. AU - Li, Jian Feng. AU - Ling, Xing Yi. AU - Maier, Stefan A.. AU - Mayerhöfer, Thomas. AU - Moskovits, Martin. AU - Murakoshi, Kei. AU - Nam, Jwa Min. AU - Nie, Shuming. AU - Ozaki, Yukihiro. AU - Pastoriza-Santos, Isabel. AU - Perez-Juste, Jorge. AU - Popp, Juergen. AU - Pucci, ...
Vol 9: Performance-Enhancing Methods for Au Film over Nanosphere Surface-Enhanced Raman Scattering Substrate and Melamine Detection Application.. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
We have introduced an in-situ Raman monitoring technique to investigate the crystallization process inside protein drops. In addition to a conventional vapour-diffusion process, a novel procedure which actively stimulates the evaporation from a protein drop during crystallization was also evaluated, with lysozyme as a model protein. In contrast to the conventional vapour-diffusion condition, the evaporation-stimulated growth of crystals was initiated in a simple dehydration scheme and completed within a significantly shorter time. To gain an understanding of crystallization behaviours under the conditions with and without such evaporation stimulation, confocal Raman spectroscopy combined with linear regression analysis was used to monitor both lysozyme and HEPES buffer concentrations in real time. The confocal measurements having a high spatial resolution and good linear response revealed areas of local inhomogeneity in protein concentration when the crystallization started. The acquired ...
This paper reports the first vibrational Raman optical activity (ROA) spectrum of a glycoprotein. The sample, orosomucoid (α1-acid glycoprotein), shows ROA bands characteristic of a high β-sheet content together with new bands which could be specific for the carbohydrate and its association with the protein. Our results suggest that ROA spectra of intact glycoproteins may contain information about both protein and carbohydrate conformation and the mutual influence on each others stability and conformation. ...
The formation of Ni silicides has been successfully monitored by Raman spectroscopy. Ni silicides formed at different annealing temperatures using rapid thermal annealing were analyzed using Rutherford backscattering spectroscopy and X-ray diffraction. Raman spectroscopy was further used to examine these samples. The results showed that Raman spectroscopy could accurately identify the phases of Ni silicides formed at various temperatures. These findings were used to demonstrate the increased thermal stability of NiSi by the addition of Pt. This study demonstrates the applicability of Raman spectroscopy for monitoring the formation of NiSi, which was suggested to be the future silicide for deep submicrometer integrated circuit processing. Raman spectroscopy offers a unique tool for phase identification at localized areas and mapping characterization of Ni silicides with micrometer spatial resolution ...
Christian Knipfer,1,3,* Johanna Motz,1 Werner Adler,4 Kathrin Brunner,5 Medhaine Tesfay Gebrekidan,2,3 Robert Hankel,2,3 Abbas Agaimy,5 Stefan Will,2,3 Andreas Braeuer,2,3 Friedrich Wilhelm Neukam,1,3 and Florian Stelzle1,3 1Department of Oral and Maxillofacial Surgery, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Erlangen, Germany 2Lehrstuhl für Technische Thermodynamik, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Erlangen, Germany 3Erlangen Graduate School in Advanced Optical Technologies (SAOT), Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Erlangen, Germany 4Department of Medical Informatics, Biometry and Epidemiology, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Erlangen, Germany 5Department of Pathology, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Erlangen, Germany *Corresponding author: [email protected] ...
G-Quadruplex (G4) structures of a human telomeric 24-mer (5′-TTAGGGTTAGGGTTAGGGTTAGGG-3′) sequence (Tel24) stabilized by sodium and potassium ions have been assessed using surface-enhanced Raman scattering (SERS) spectroscopy. The distinctive SERS spectra of Tel24 in the presence of 100 mM Na+ and 100 mM K+ were obtained and the SERS bands characteristic of the antiparallel baskettype and the mixed hybrid (3+1) structures, respectively, were identified and assigned. The influence of the SERS - active substrate on the scattering enhancement was studied using citrate- and chloride-covered silver nanoparticles, in the absence and presence of the aggregating agent (0.1 M Na2SO4 and 0.1 M K2SO4). The highly reproducible SERS spectra of Tel24 obtained in various SERS active media indicated the same adsorption mechanism of the cation - stabilized G-quadruplexes onto the metal surface, regardless of the silver colloid. The remarkable resemblance between the circular dichroism (CD) spectra of the ...
Human telomeric G-quadruplexes are emerging targets in anticancer drug discovery since they are able to efficiently inhibit telomerase, an enzyme which is
ABSTRACT-UV-visible reflectance spectroscopy and Raman microspectroscopy provide a rapid way to unequivocally identify the pre-Columbian pigment Maya blue. Spectra of modern synthetic materials are compared with data from a contextualized archaeological sample and from an object in the collection of the Los Angeles County Museum of Art. UV-visible spectroscopy and Raman microspectroscopy, together with complementary techniques such as Fourier transform infrared microspectroscopy, reveal significant differences between spectra of indigo as pure crystalline solid or as complexed by palygorskite. These techniques are thus extremely specific, being able to identify Maya blue as a prepared pigment rather than detecting only its ingredients, indigo and palygorskite. Fiber optics UV-visible reflectance spectroscopy and Raman microspectroscopy present the additional advantage of being completely noninvasive and therefore suitable for the study of works of art. Lightweight portable fiber optics ...
Two-photon polymerization (TPP) is an enabling technology that allows fast prototyping of parts with sub-100 nm resolution. Due to its ability to fabricate microstructures with arbitrary three-dimensional geometries, TPP has been employed in diverse fields such as nanophotonics, microelectronics, microelectromechanical systems, and microfluidics. However, no information is available to date that microscopically correlates the experimental conditions used in TPP with the properties of the ultimate microstructure. We present a study where the distribution of polymer cross-linking in three-dimensional microstructures fabricated by TPP is visualized by means of coherent anti-Stokes Raman scattering (CARS) microscopy. The characterization of the microstructures based on the acquired images permits rational optimization of the TPP process
TY - JOUR. T1 - Resonance Raman spectra of ferrochelatase reveal porphyrin distortion upon metal binding. AU - Blackwood, Milton E.. AU - Rush, Thomas S.. AU - Medlock, Amy Elizabeth. AU - Dailey, Harry A.. AU - Spiro, Thomas G.. PY - 1997/12/17. Y1 - 1997/12/17. N2 - Ferrochelatase catalyzes Fe2+ insertion into porphyrins, and is inhibited by Hg2+. Resonance Raman spectra of mesoporphyrin IX show that binding to ferrochelatase restricts the conformation of the propionate side chains, but does not perturb the ring conformation. However, a pronounced perturbation is seen in the ternary complex with Hg2+. Several additional RR bands are activated, including some arising from [R-active vibrations, establishing loss of an effective symmetry center. Out-of-plane modes appear in the low frequency region. The strongest of these bands, γ5 and γ6, correspond to pyrrole tilting vibrations, which are in the same symmetry class as a doming distortion of the porphyrin. All four pyrrole N atoms are pointing ...
Resonance Raman spectroscopy was used to probe the effect of solvent polarity on the molecular structure and isomerization dynamics of $4-nitro-4^\prime -dimethylaminoazobenzene$ (DA). In addition, the influence of the polarity and the relaxation behavior of the solvent on the mode-specific vibrational and solvent reorganization energies was investigated. Raman spectra were recorded in solvents with different polarity parameters, n-hexane and benzene, using 11 excitation wavelengths in the range 450-550 nm, scanning every 10 nm using the tunable laser pulse output of an optical parametric oscillator. It was observed that the solvent polarity plays a major role in influencing the excited-state potential energy surfaces of DA. The plot of resonance Raman intensities versus excitation wavelength (Raman excitation profiles) of the Franck-Condon-active fundamentals of DA shows that in n-hexane, the locally excited state is more favorable than that in benzene where the charge-transfer state is more ...
Nanoporous thin films with silver nanoparticles were synthesized with a bottom-up approach, and its potential as effective surfaceenhanced Raman scattering (SERS) substrates was demonstrated. The use of mesoporous titania films as substrates allowed to control the growth of nanoparticles on the film surface. Atomic force microscopy measurements, Ultraviolet-visible and X-ray diffraction analysis confirmed the photoreduction of Ag+ to Ag0 with the formation of nanoparticles with crystallite dimensions of 32 to 36 nm. The new substrates allowed the detection of two analytes (rhodamine B isothiocyanate and cytochrome c), present in solutions at very low concentrations, highlighting their potential in SERS sensing. Reproducibility, homogeneity, enhancement factor of the substrate, consistency of results and detection limits were also assessed. ...
Objective: Regeneration of the CNS and PNS cannot be monitored until we have a final functional readout: movement or paresis. Therefore, there is an urgent need for in vivo imaging modalities to analyse and control therapeutic impact after damage to the nervous system. We investigated time-dependent morphochemical tissue changes after CNS and PNS injury in the axolotl by label-free multiphoton microscopy (MPM).. Method: Two models of injury were investigated: spinal cord transection or sciatic nerve transection, cryosections of the injured area were prepared at 0d, 2d, 7d, 14d, 24d, 28d, 42d and 100d post-lesioning (n=10 per time point) and analyzed with MPM. Specifically, coherent anti-stokes Raman scattering (CARS) probed lipid-rich myelin via visualization of CH2 vibrations, while two photon excited fluorescence (TPEF) and second harmonic generation (SHG) displayed endogenous fluorophores and collagen, respectively. Immunostaining for myelin basic protein, neurofilament and ionized calcium ...
While there have been many publications produced in which Raman spectroscopy has been used to characterize various aspects of carbon nanostructures, there have been few works published which provide an overview of what the technique can offer to the field of carbon nanostructures, and works which discuss optimization of analysis parameters and the variation that is observed as those parameters are varied are still lacking. This poster will provide an overview of the information that Raman spectroscopy can provide on carbon nanostructures with emphasis placed on carbon nanotubes and graphene. This work will go further to demonstrate the impact that varying key analysis parameters such as laser power will have on the measurements. The goal of this poster is to provide people who are looking to characterize carbon nanostructures with an understanding of what Raman spectroscopy can offer and with some insight on how to optimize measurement conditions.
While there have been many publications produced in which Raman spectroscopy has been used to characterize various aspects of carbon nanostructures, there have been few works published which provide an overview of what the technique can offer to the field of carbon nanostructures, and works which discuss optimization of analysis parameters and the variation that is observed as those parameters are varied are still lacking. This poster will provide an overview of the information that Raman spectroscopy can provide on carbon nanostructures with emphasis placed on carbon nanotubes and graphene. This work will go further to demonstrate the impact that varying key analysis parameters such as laser power will have on the measurements. The goal of this poster is to provide people who are looking to characterize carbon nanostructures with an understanding of what Raman spectroscopy can offer and with some insight on how to optimize measurement conditions.
Eggeling, C.; Schaffer, J.; Seidel, C.; Korte, J.; Brehm, G.; Schneider, S.; Schrof, W.: Homogeneity, transport and signal properties of single Ag particles studied by single-molecule surface-enhanced resonance Raman scattering. Journal of Physical Chemistry A 105, pp. 3673 - 3679 (2001 ...
Research in the Fu group focuses on developing novel optical spectroscopy and imaging techniques to investigate the spatial-temporal dynamics of living biological systems at single cell resolution. In particular, we are interested in using label-free spectroscopic imaging approaches such as stimulated Raman scattering microscopy to study the cellular mechanism of complex diseases such as cancer and metabolic disorders. We draw on expertise from multiple disciplines including analytical chemistry, ultrafast spectroscopy, imaging science, optical engineering, bioinstrumentation, cell biology, and systems biology.. Label-free optical microscopy. Optical microscopy, especially fluorescence microscopy, is instrumental in unraveling the intricate biological processes that happen inside living cells. However, most biomolecules in the cell do not fluorescence and visualizing those molecules requires fluorescent tags, which may often be unavailable or perturbative to their biological functions. We ...
Microthermometry is the most common technique used to determine the salinity of aqueous fluid inclusions but, in some cases, this technique cannot be applied. The Raman analysis of water is a good alternative. Instead of preparing fluid inclusions within minerals by the crack-and-heal method, fused-silica capillary capsules (FSCCs) were used as synthetic fluid inclusions to calibrate the Raman signal of water toward chlorinity. The preparation of FSCCs is convenient in the preparation of synthetic fluid inclusions, and the composition of the standard solutions is well controlled all along the preparation procedure. Standard fluid compositions made in FSCCs are stable over time. The treatment of Raman data is reduced to the subtraction of a straight baseline and the measurement of Raman intensity at two wavenumbers, such that it is simple and independent from the operator. The method has been tested by comparison of the results obtained from Raman spectroscopy and with phase transitions observed ...
Dr. Tuan Vo-Dinh is R. Eugene and Susie E. Goodson Distinguished Professor of Biomedical Engineering, Professor of Chemistry, and Director of The Fitzpatrick Institute for Photonics.. Dr. Vo-Dinhs research activities and interests involve biophotonics, nanophotonics, plasmonics, laser-excited luminescence spectroscopy, room temperature phosphorimetry, synchronous luminescence spectroscopy, surface-enhanced Raman spectroscopy, field environmental instrumentation, fiberoptics sensors, nanosensors, biosensors and biochips for the protection of the environment and the improvement of human health.. Dr. Vo-Dinhs research activities and interests include the development of advanced technologies and methods in biophotonics, nanophotonics, biosensors, biochips, plasmonics, multi-modality bioimaging, and theranostics (diagnostics and therapy) of diseases such as cancer and infectious diseases. We have pioneered the development of a new generation of gene probes using surface-enhanced Raman scattering ...
Dr. Tuan Vo-Dinh is R. Eugene and Susie E. Goodson Distinguished Professor of Biomedical Engineering, Professor of Chemistry, and Director of The Fitzpatrick Institute for Photonics.. Dr. Vo-Dinhs research activities and interests involve biophotonics, nanophotonics, plasmonics, laser-excited luminescence spectroscopy, room temperature phosphorimetry, synchronous luminescence spectroscopy, surface-enhanced Raman spectroscopy, field environmental instrumentation, fiberoptics sensors, nanosensors, biosensors and biochips for the protection of the environment and the improvement of human health.. Dr. Vo-Dinhs research activities and interests include the development of advanced technologies and methods in biophotonics, nanophotonics, biosensors, biochips, plasmonics, multi-modality bioimaging, and theranostics (diagnostics and therapy) of diseases such as cancer and infectious diseases. We have pioneered the development of a new generation of gene probes using surface-enhanced Raman scattering ...
CRAIC Technologies has developed a new solution for the semiconductor industry: the 20/20 XL™ Film Thickness Measurement Tool. The 20/20 XL™ is a microspectrophotometer is designed to non-destructively analyze microscopic areas of very large samples. This system offers the ability to measure the thickness of thin films in both transmission and reflectance.
The characteristic AgcoreAushell nanoparticles as SERS substrates in detecting dopamine molecules at various pH ranges Yanru Bu,1 Sang-Wha Lee2 1Department of Chemical Engineering, Faculty of Engineering, Monash University, Melbourne, VIC, Australia; 2Department of Chemical and Biochemical Engineering, Gachon University, Seongnam-si, Gyeonggi-do, Republic of Korea Abstract: AgcoreAushell nanoparticles (NPs) are a promising surface-enhanced Raman scattering (SERS) substrate, which can offer a high enhancement factor through the combined effect of the high SERS activity of the Ag core and the biocompatibility of the Au shell. In this study, AgcoreAushell NPs were examined as SERS substrates for the sensitive detection of dopamine (DA) molecules in an aqueous solution. The SERS activity of the AgcoreAushell NPs was strongly dependent on the pH of the solution. When the pH of the solution was acidic (pH 9), the AgcoreAushell NPs exhibited negligible SERS activity toward the DA molecules, due to the
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a set of infrared and Raman spectra of 500 common and artificial polymers of commercial value is gifted during this publication. a wide number of compounds are incorporated, beginning with linear polyolefins and completing with complicated biopolymers and similar compounds. The spectra have been registered utilizing Infrared Fourier remodel Spectrometers within the laboratory of the All-Russia Institute of Forensic Sciences. The IR and Raman spectra are awarded jointly at the related sheet. The accompanying information comprise normal and constitution formulae, CAS sign in numbers, and pattern training conditions.. Features of this book:. • keeps the lengthy culture of publishing particular and traditional info of latest chemical compounds.. • For low-molecular weight ingredients, complementary IR and Raman spectra are featured at the comparable pattern and imprinted on the comparable web page. This fingerprint info permits the substance of the pattern to be pointed out with no ...
Very small, thioglycerol (TG)-capped CdS nanoparticles were synthesized by a wet chemical technique and investigated in the framework of this thesis. Also glutathione-capped particles were investigated for a comparison of the capping agents. High-resolution photoelectron spectroscopy using high-brilliance synchrotron radiation was applied as the major tool for the characterization of these particles. Additionally, the particles were investigated with UV-VIS absorption spectroscopy, XPS using a laboratory source, valence band photoemission spectroscopy (VBPES), near-edge x-ray absorption spectroscopy (NEXAFS), and micro-Raman spectroscopy to address various aspects of the particles. In the beginning, an overview on size quantization effects is given to create a theoretical background behind the work presented in this thesis. Furthermore, an overview of various conventional techniques for size determination is presented. Exact information about size, shape and size distribution of nanoparticles is ...
Retinoic acid (RA) is essential for early developmental processes and stem cell differentiation, but less is known about its contributions to adult tissues and stem cells including adipose tissue. We previously demonstrated that many genes involved in RA synthesis and downstream pathway are differentially expressed in adipose-derived stem cells (ASCs) from visceral fat compared to those from subcutaneous fat, leading to changes in their early adipogenic functions. In order to study potential contributions of RA in adipose tissue, we measured tissue RA levels using a technique based on surface-enhanced Raman spectroscopy (SERS). The data indicate heretofore underappreciated abundance of endogenous RA in mouse adipose tissue compared to other tissues and dynamic changes of RA concentrations after high fat diet feeding. Our results lay the foundation for further investigation on the functional role of RA in adipose tissue development and metabolism ...
The resonance Raman (RR) spectra of six types of human brain tissues are examined using a confocal micro-Raman system with 532-nm excitation in vitro. Forty-three RR spectra from seven subjects are investigated. The spectral peaks from malignant meningioma, stage III (cancer), benign meningioma (benign), normal meningeal tissues (normal), glioblastoma multiforme grade IV (cancer), acoustic neuroma (benign), and pituitary adenoma (benign) are analyzed. Using a 532-nm excitation, the resonance-enhanced peak at 1548 cm−1 (amide II) is observed in all of the tissue specimens, but is not observed in the spectra collected using the nonresonance Raman system. An increase in the intensity ratio of 1587 to 1605 cm−1 is observed in the RR spectra collected from meningeal cancer tissue as compared with the spectra collected from the benign and normal meningeal tissue. The peak around 1732 cm−1 attributed to fatty acids (lipids) are diminished in the spectra collected from the meningeal cancer tumors ...
The influence of porosity on the superconducting properties have been investigated on YBa/sub 2/Cu/sub 3/O/sub 7/ thin films deposited on LaAlO/sub 3/ [100] substrates by the so-called Trifluoroacetate (TFA) route. Micro-Raman spectroscopy have been used to determine the concentration of c-axis grains /spl delta/ in different samples and their influence on the final film porosity as observed from SEM imaging. This has been compared with measurements of resistivity and critical currents in the same samples. We prove that this /spl delta/ fraction is the main parameter controlling the porosity and hence the normal-state resistivity of the thin films. The optimization of the microstructure of these YBa/sub 2/Cu/sub 3/O/sub 7/ TFA films allow to have high critical currents : J/sub c/ = 3 /spl times/ 10/sup 6/ A/cm/sup 2/ at 77 K ...
Quantum chemical calculations on the geometrical, conformational, spectroscopic (FTIR, FT-Raman) analysis and NLO activity of milrinone [5-cyano-2-methyl-(3,4-bipyridin)-6(1h)-one] by using hartree-fock and density functional methods
Differential reflectivity (ZDR) and circular depolarization ratio (CDR) radar signals are directly related to each other and to the median drop size diameter of rainfall when the drop sizes are exponentially distributed. These polarization parameters are examined for both static and oscillating raindrop shapes along with their relationships with rainfall rate and liquid water content estimates derived from ZDR or CDR and reflectivity factor (Z) measurements. Propagation effects at S band wavelengths are also considered and shown to be particularly important in CDR measurements. ...
Therapeutic and subtherapeutic use of veterinary drugs has increased the risk of residue contamination in animal food products. Antibiotics such as tetracycline are used for mastitis treatment of lactating cows. Milk expressed from treated cows before the withdrawal period has elapsed may contain tetracycline residue. This study developed a simple surface-enhanced Raman spectroscopic (SERS) method for on-site screening of tetracycline residue in milk and water. Six batches of silver colloid nanoparticles were prepared for surface enhancement measurement. Milk-tetracycline and water-tetracycline solutions were prepared at seven concentration levels (1000, 500, 100, 10, 1, 0.1, and 0.01 ppm) and spiked with silver colloid nanoparticles. A 785 nm Raman spectroscopic system was used for spectral measurement. Tetracycline vibrational modes were observed at 1285, 1317 and 1632 cm−1 in water-tetracycline solutions and 1322 and 1621 cm−1 (shifted from 1317 and 1632 cm−1, respectively) in milk-tetracycline
TY - GEN. T1 - Effect of silver concentration towards formation of agpt nanofern films as sers substrates. AU - Norhayati, Abu Bakar. AU - Nur, Adliha Abdullah. AU - Akrajas, Ali Umar. AU - Mat Salleh, Muhamad. AU - Joseph, George Shapter. PY - 2019/1/1. Y1 - 2019/1/1. N2 - This paper reports the preparation of silver-platinum (AgPt) nanoferns on ITO surface using liquid phase deposition technique with various concentrations of silver nitrate in synthesis solution. The different morphologies of AgPt thin films were grown on the surface using 0.1 mM to 0.8 mM of silver concentration. This silver effect on the growth of AgPt on the surface was studied using FESEM and UV-Vis characterization. It was found that the optimum silver concentration in synthesis solution supplied the appropriate Ag+ ion to grow the nanoferns structure on the surface. AgPt films were then carried out to sense 1.0 M of creatinine concentration to learn their performance as surface-enhanced Raman scattering (SERS) substrate. ...
Raman spectroscopy has emerged as a promising tool for real-time clinical diagnosis of malignant skin tumors offering a number of potential advantages: it is non-intrusive, it requires no sample preparation, and it features high chemical specificity with minimal water interference. However, in vivo tissue evaluation and accurate histopathological classification remain a challenging task for the successful transition from laboratory prototypes to clinical devices. In the literature, there are numerous reports on the applications of Raman spectroscopy to biomedical research and cancer diagnostics. Nevertheless, cases where real-time, portable instrumentations have been employed for the in vivo evaluation of skin lesions are scarce, despite their advantages in use as medical devices in the clinical setting. This paper reviews the advances in real-time Raman spectroscopy for the in vivo characterization of common skin lesions. The translational momentum of Raman spectroscopy towards the clinical practice