Raman Spectroscopic Analysis of Saliva for the Diagnosis of Oral Cancer: a Systematic Review

Abstract Oral squamous cell carcinoma (OSCC) is one of the most common malignancies worldwide, and new protocols for routine and early detection are required. Raman spectroscopy is an optical based method that can provide sensitive and non-invasive real time detailed information on the biochemical content of a sample like saliva, through the unique vibrations of its constituent molecules and this is sensitive to changes associated with disease. A comprehensive systematic review of the available scientific literature related to Raman spectroscopy of human saliva for diagnosis of OSCC was performed. The 785 nm laser line was most applied wavelength along with principal components analysis associated with linear discriminant analysis. The main salivary components possibly associated with the presence of OSCC were proteins and lipids. Measurement in the liquid physical state, and with no addition of nanoparticles for signal enhancement, seemed to best conserve the salivary integrity. However, in terms of sampling protocols, no differentiation was generally made between stimulated and non-stimulated saliva. Raman spectroscopy of saliva holds a promising future for clinical applications such as early detection of OSCC. However, more systematic analyses are still required for a better elucidation regarding sampling procedure, storage and degradation

Surface Enhanced Raman Spectroscopy for Quantitative Analysis: Results of a Large-Scale European Multi-Instrument Interlaboratory Study

peer reviewedaudience: researcher, professional, studentSurface-enhanced Raman scattering (SERS) is a powerful and sensitive technique for the detection of fingerprint signals of molecules and for the investigation of a series of surface chemical reactions. Many studies introduced quantitative applications of SERS in various fields, and several SERS methods have been implemented for each specific application, ranging in performance characteristics, analytes used, instruments, and analytical matrices. In general, very few methods have been validated according to international guidelines. As a consequence, the application of SERS in highly regulated environments is still considered risky, and the perception of a poorly reproducible and insufficiently robust analytical technique has persistently retarded its routine implementation. Collaborative trials are a type of interlaboratory study (ILS) frequently performed to ascertain the quality of a single analytical method. The idea of an ILS of quantification with SERS arose within the framework of Working Group 1 (WG1) of the EU COST Action BM1401 Raman4Clinics in an effort to overcome the problematic perception of quantitative SERS methods. Here, we report the first interlaboratory SERS study ever conducted, involving 15 laboratories and 44 researchers. In this study, we tried to define a methodology to assess the reproducibility and trueness of a quantitative SERS method and to compare different methods. In our opinion, this is a first important step toward a "standardization" process of SERS protocols, not proposed by a single laboratory but by a larger community. Copyright © 2020 American Chemical Society

Dataset for Surface Enhanced Raman Spectroscopy for quantitative analysis: results of a large-scale European multi-instrument interlaboratory study

This dataset contains all the spectra used in "Surface Enhanced Raman Spectroscopy for quantitative analysis: results of a large-scale European multi-instrument interlaboratory study". Data are available in 2 different formats: - a compressed archive with 1 folder ("Dataset”) cointaining all the 3516 TXT files (1 file = 1 spectrum) uploaded by all participants (all spectra of the Interlaboratory study); - 1 single CSV file (“ILSspectra.csv”) with all the 3516 spectra uploaded by all participants in the form of a table. The data are structured as follow, with each row being 1 spectrum, preceded by metadata: "labcode", "substrate", "laser", "method", "sample", "type", "conc", "batch", "replica". Note that for those spectra starting after 400 cm-1 and/or ending before 2000 cm-1 missing values were expressed as NAs