Emerging Raman spectroscopy and saliva-based diagnostics: from challenges to applications

Spectral effects and enhancement quantification in healthy human saliva with surface‐enhanced Raman spectroscopy using silver nanopillar substrates

“…In healthcare and biomedical applications, the analysis of biomarkers lacks standardization in methodology and analysis, hindering commercialization and real-world use. 30,31 In addition, the low efficiency of Raman scattering coupled to the sensitivity and specificity required for biomedical diagnosis can necessitate high integration time and laser power, which can limit practical use in clinical applications. 41 For example, the laser power for an in vivo measurement should be limited to avoid tissue damages [42][43][44] and acquisition time must be short to fit into the clinical workflow, e.g., for surgical applications.…”

“…Recently, our group demonstrated the use of label‐free Raman micro‐spectroscopy for saliva‐based detection of COVID‐19 infection in samples from a testing clinic 6 . Several studies have used spontaneous RS and SERS for biomedical diagnostics, without establishing a large baseline of the signature of healthy saliva 6,30,31,54,64 …”

“…6,[12][13][14][15][16][17][18][19][20][21][22] Raman spectroscopy, coupled with machine learning (ML) techniques, can detect biomolecular features associated with vibrational modes of bonds from lipids, nucleic acids, proteins, as well as specific amino acids. 12,13,[23][24][25][26][27] Raman spectroscopy has been applied to biofluids for multiple detection purposes in dentistry, [28][29][30][31] forensics, [30][31][32][33][34][35] illicit drugs 30,31,[36][37][38] and healthcare. 30,31,39,40 Raman spectroscopy is an optical technique that uses a spectrometer to measure the inelastic scattering of light following sample illumination with a monochromatic laser source, usually in the near-infrared range to limit the impact of fluorescence from biomolecules.…”

“…12,13,[23][24][25][26][27] Raman spectroscopy has been applied to biofluids for multiple detection purposes in dentistry, [28][29][30][31] forensics, [30][31][32][33][34][35] illicit drugs 30,31,[36][37][38] and healthcare. 30,31,39,40 Raman spectroscopy is an optical technique that uses a spectrometer to measure the inelastic scattering of light following sample illumination with a monochromatic laser source, usually in the near-infrared range to limit the impact of fluorescence from biomolecules. The method provides a non-destructive, and label-free molecular fingerprint that is intrinsic to the probed sample.…”

“…6 Several studies have used spontaneous RS and SERS for biomedical diagnostics, without establishing a large baseline of the signature of healthy saliva. 6,30,31,54,64 In this paper, we present SERS and spontaneous RS measurements from 161 dried saliva samples from healthy donors. The spectral datasets were acquired using two spectroscopic imaging systems based on specimen interrogation protocols optimized for saliva supernatant.…”