Raman Spectroscopy: An Emerging Tool in Neurodegenerative Disease Research and Diagnosis

Abstract

The pathogenesis underlining many neurodegenerative diseases remains incompletely understood. The lack of effective biomarkers and disease preventative medicine demands the development of new techniques to efficiently probe the mechanisms of disease and to detect early biomarkers predictive of disease onset. Raman spectroscopy is an established technique that allows the label-free fingerprinting and imaging of molecules based on their chemical constitution and structure. While analysis of isolated biological molecules has been widespread in the chemical community, applications of Raman spectroscopy to study clinically relevant biological species, disease pathogenesis, and diagnosis have been rapidly increasing since the past decade. The growing number of biomedical applications has shown the potential of Raman spectroscopy for detection of novel biomarkers that could enable the rapid and accurate screening of disease susceptibility and onset. Here we provide an overview of Raman spectroscopy and related techniques and their application to neurodegenerative diseases. We further discuss their potential utility in research, biomarker detection, and diagnosis. Challenges to routine use of Raman spectroscopy in the context of neuroscience research are also presented.

Detection and identification of canker and blight on orange trees using a hand‐held Raman spectrometer

“…Vibrational mode Assignment 747 γ(C─O─H) of COOH Pectin [25] 915 ν(C─O─C) in plane, symmetric Cellulose and lignin [26] 1,000 ν 3 (C─CH 3 stretching) and phenylalanine Carotenoids and protein [27,28] 1,155 asym ν(C─C) ring breathing Carbohydrates and cellulose [26] 1,184 ν(C─O─H) next to aromatic ring+σ (CH) Xylan [29,30] 1,218-1,226 δ(C─C─H) Aliphatic [31] and xylan [29] 1,247 C─O stretching (aromatic) Lignin [32] 1,288 δ(C─C─H) Aliphatic [31] 1,326 δCH 2 bending vibration Cellulose and lignin [26] 1,382 δCH 2 bending vibration Aliphatic [31] 1,440 δ (CH 2 ) + δ (CH 3 ) Aliphatic [31] 1,455 δCH 2 bending vibration Aliphatic [31] 1,488 δ (CH 2 ) + δ (CH 3 ) Aliphatic [31] 1,527-1,551 ─C═C─ (in plane) Carotenoids [33,34] 1,601 ν(C─C) aromatic ring+σ (CH) Lignin [35,36] 1,630 C═C─C (ring) Lignin [35][36][37] intensities of all other bands in the spectra collected from leaves of CA and HLB + BL exhibited only very small variations compared with the spectra collected from leaves of HL trees.…”

Human placental villi contain stromal macrovesicles associated with networks of stellate cells

“…Raman spectroscopy would be an in situ way of identifying whether the stromal macrovesicles contain lipid (Devitt et al. ). Mass spectroscopy‐based microscopy may be another approach but it does not currently have the required resolution (Norris & Caprioli, ).…”

“…This would allow flow cytometry of placental homogenates in order to identify and purify these stromal macrovesicles (Welsh et al 2019). Raman spectroscopy would be an in situ way of identifying whether the stromal macrovesicles contain lipid (Devitt et al 2018). Mass spectroscopy-based microscopy may be another approach but it does not currently have the required resolution (Norris & Caprioli, 2013).…”

SERS‐based biosensor for Alzheimer disease evaluation through the fast analysis of human serum

“…RS is a nondestructive, reagent, and label‐free technique that can rapidly provide an overview of the chemical bonding and molecular structures of a sample. Because of the limited sample preparation required, RS was already proved to be effective in cancer diagnosis by the analysis of tissues and cells and also in the neurodegenerative field as recently reviewed by Devitt et al . What makes neurodegenerative disorders suitable for the RS approach is the central hallmark of most diseases, that is, the protein misfolding and aggregation, that can alter the Raman spectrum providing information about the structural organization of amyloid fibrils .…”