1,721,044 research outputs found
Nanostrucured substrates for surface-enhanced Raman scattering spectroscopy
Full text linkAfter introducing the basics and the most relevant experimental aspects of surface-enhanced Raman scattering (SERS), nanostructured metal substrates used as substrates in this technique are discussed. First, general characteristics are considered, and then colloidal and noncolloidal substrates are specifically addressed. Both bottom-up and top-down strategies for substrates preparation are discussed, along with commonly used characterization techniques. A third part is specifically dedicated to how SERS substrates can be used for in vitro and in vivo diagnostics and theranostics, stressing the two different “direct” and “indirect” detection strategies, and the role of the nanobio interface
Label-free surface-enhanced Raman scattering for clinical applications
No full textIl capitolo descrive gli aspetti sperimentali generali riguardanti l'applicazione della tecnica SERS a campioni biologici, con particolare riferimento ai biofluidi, a scopi diagnostici e clinici
Data analysis in SERS diagnostics
No full textSurface-enhanced Raman spectroscopy (SERS) datasets obtained from biomedical samples are rich in information, but this wealth of information is not always easy to get. Extracting the right information from this complexity is a challenging task. Preprocessing procedures and multivariate analysis methods are extremely powerful tools to help us in this task. These tools, however, are as powerful as dangerous, if not correctly used, and can easily lead to wrong conclusions. This chapter is a short introduction into the analysis and interpretation of SERS spectral data in biomedical studies. The aim is to give practical advices to the researcher through a quick overview of the most relevant techniques for data visualization and analysis, with an emphasis on both their capabilities and weaknesses
Surface-enhanced Raman spectroscopy of the anti-cancer drug irinotecan in presence of human serum albumin
No full textThe development of nanotechnological devices and their clinical application in medicine has become increasingly important, especially in the context of targeted and personalized therapy. This is particularly important in cancer therapy, where antitumor drugs are highly cytotoxic and often exert their therapeutic effect at concentrations close to systemic toxicity. In the last years a growing number of studies has started to report the use of plasmonic nanoprobes in the field of theranostics, broadening the application of vibrational spectroscopies like Raman scattering and surface enhanced Raman scattering (SERS) in biomedicine. The present work aims to identify and characterize the vibrational profiles of a widely used anticancer drug, irinotecan (CPT-11). With a rational approach, SERS experiments have been performed on this analyte employing both Au and Ag colloids, starting from simple aqueous solutions up to albumin mixtures. A major step forward for drug detection in albumin solutions has been taken with the adoption of a simple deproteinization strategy, and a two-in-one-step separation and identification by coupling thin layer chromatography, TLC, with SERS (TLC-SERS). The latter has revealed to be a valid system for protein separation and simultaneous analyte detection, showing a potential to become an innovative, sensitive and low cost method for antineoplastic drug profiling in patients' body fluids
Dataset for Direct comparison of different protocols to obtain Surface enhanced Raman spectra of human serum
No full text<p>This dataset contains all the spectra used in "Direct comparison of different protocols to obtain Surface enhanced Raman spectra of human serum ". Data are available in a compressed folder ("Dataset serum spectra") containing all the 75 TXT files (1 file=1 spectrum) of the same serum sample analyzed with the 5 protocols presented in the article. </p>
<p>The script employed for loading, preprocessing, and analyzing the dataset is named "Script for spectra analysis." Furthermore, the DOCX file ("Instructions") provides details concerning the metadata embedded within the title of each TXT file. </p>
Direct comparison of different protocols to obtain surface enhanced Raman spectra of human serum
Full text linkLabel-free Surface Enhanced Raman Spectroscopy (SERS) is a rapid technique that has been extensively applied in clinical diagnosis and biomedicine for the analysis of biofluids. The purpose of this approach relies on the ability to detect specific “metabolic fingerprints” of complex biological samples, but the full potential of this technique in diagnostics is yet to be exploited, mainly because of the lack of common analytical protocols for sample preparation and analysis. Variation of experimental parameters, such as substrate type, laser wavelength and sample processing can greatly influence spectral patterns, making results from different research groups difficult to compare. This study aims at making a step toward a standardization of the protocols in the analysis of human serum samples with Ag nanoparticles, by directly comparing the SERS spectra obtained from five different methods in which parameters like laser power, nanoparticle concentration, incubation/deproteinization steps and type of substrate used vary. Two protocols are the most used in the literature, and the other three are “in-house” protocols proposed by our group; all of them are employed to analyze the same human serum sample. The experimental results show that all protocols yield spectra that share the same overall spectral pattern, conveying the same biochemical information, but they significantly differ in terms of overall spectral intensity, repeatability, and preparation steps of the sample. A Principal Component Analysis (PCA) was performed revealing that protocol 3 and protocol 1 have the least variability in the dataset, while protocol 2 and 4 are the least repeatable
The key role of ergothioneine in label‐free surface‐enhanced Raman scattering spectra of biofluids: a retrospective re‐assessment of the literature
Full text link: Label-free surface-enhanced Raman scattering (SERS) has recently gained attention in the field of liquid biopsy as a rapid and relatively inexpensive technique that could significantly ease clinical diagnosis and prognosis by investigating a biofluid sample with a laser. Indeed, SERS spectra provide information about a set of metabolites present in the analyzed biofluid thereby offering biochemical insight into specific health conditions. Ergothioneine plays a key role since it is one of the few metabolites in biofluids that are detectable by label-free SERS. In the past decade, many studies characterizing biofluids or other biological samples have unknowingly linked this amino acid with crucial metabolic processes, including inflammation, in a plethora of diseases. However, since the SERS spectrum of ergothioneine has been reported only recently, most past studies inadvertently assigned what are now recognized as the spectral features of this compound to other molecules. The purpose of the present review is to summarize and re-evaluate these studies in light of the recent SERS characterization of ergothioneine so as to better recognize the role of Ergothioneine in many clinical conditions
Potential of Surface Enhanced Raman Spectroscopy (SERS) in Therapeutic Drug Monitoring (TDM). A Critical Review
Full text linkSurface-Enhanced Raman Spectroscopy (SERS) is a label-free technique that enables quick monitoring of substances at low concentrations in biological matrices. These advantages make it an attractive tool for the development of point-of-care tests suitable for Therapeutic Drug Monitoring (TDM) of drugs with a narrow therapeutic window, such as chemotherapeutic drugs, immunosuppressants, and various anticonvulsants. In this article, the current applications of SERS in the field of TDM for cancer therapy are discussed in detail and illustrated according to the different strategies and substrates. In particular, future perspectives are provided and special concerns regarding the standardization of self-assembly methods and nanofabrication procedures, quality assurance, and technology readiness are critically evaluated
Characterization of white wines from north-eastern Italy with surface-enhanced Raman spectroscopy
No full textIn the present study, label-free SERS spectroscopy is applied as a useful analytical technique for white wine characterization.
180 samples of three white wines varieties from northeastern Italy, Sauvignon Blanc, Ribolla Gialla and Friulano, collected from three different Italian producers from 2016 vintage, have been analyzed using Ag citrate-reduced colloids and a portable Raman instrument with a 785 nm laser.
A PCA of SERS spectra showed that discrimination between wines and wineries is possible. Main spectral differences are due to adenine, carboxylic acids and glutathione, with their ratio changing among different wine types and producers. A robust version of the Soft Independent Modelling of Class Analogy (SIMCA) method was used to model the class space of each wine and to perform the classification among the different categories, yielding overall efficiencies between 87 and 93%. These results are extremely encouraging and open the way to the application of this SERS protocol as a wine identification assay
Ergothioneine, a dietary amino acid with a high relevance for the interpretation of label-free surface enhanced Raman scattering (SERS) spectra of many biological samples
Full text linkIntense SERS spectra of the natural amino acid ergothioneine (ERG) are obtained on different substrates upon 785 nm excitation. A characteristic spectral pattern with a distinctive intense band at 480–486 cm−1 is conserved when substrates of different type and characteristics are used. On the basis of available literature, we propose ERG is adsorbed on the metal surface in its thiolate form via the sulphur and heterocyclic nitrogen. The same spectral pattern is obtained in SERS spectra of filtered erythrocytes lysates, confirming the presence of ERG in those cells. The occurrence of ERG bands in label-free SERS spectra of serum and plasma reported in literature by different authors is discussed, highlighting the importance of this amino acid for the interpretation of SERS spectra of these biofluids
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