Surface-Enhanced Raman Spectroscopy for Alzheimer's Disease Biomarker Detection

Surface-Enhanced Raman Spectroscopy (SERS) has emerged as a powerful tool for the sensitive and non-invasive detection of molecular biomarkers associated with Alzheimer’s disease. By exploiting the enormous enhancement of Raman scattering signals at metallic nanostructure “hotspots,” SERS enables the identification and quantification of hallmark pathological species such as amyloid-β peptides and tau aggregates in biological fluids and tissue samples. Recent advances in nanoparticle design—ranging from gold and silver colloids to bifunctional nanoprobes combining fluorescence and Raman activity—have improved detection limits down to the picomolar range. Integration with fibre-based platforms and hyperspectral imaging further supports spatial mapping of β-sheet-rich deposits directly in unfixed brain slices, while multivariate analysis and machine-learning algorithms facilitate discrimination between healthy and diseased states. Collectively, these innovations aim to deliver a rapid, label-free, high-throughput diagnostic approach that could support early intervention strategies and monitoring of therapeutic efficacy in Alzheimer’s disease.

Research from Nature Portfolio

Recent studies have demonstrated that hyperspectral Raman imaging can visualise and quantify neuritic plaques and neurofibrillary tangles in unstained human brain tissue with micron-scale resolution. By combining hierarchical cluster analysis with Raman spectral mapping, researchers achieved simultaneous identification of proteins, lipids, water and β-sheet content, revealing significant enrichment of β-sheet structures within pathological lesions. In a complementary approach, a bifunctional nanoprobe comprising gold nanoparticles conjugated with a dye possessing intrinsic Raman fingerprints was developed to target amyloid-β peptides. Upon binding to Aβ42, the probe exhibited a notable shift in Raman spectrum alongside enhanced fluorescence emission, enabling dual-mode detection of peptide aggregates in vitro and in transgenic mouse brain sections. This multifunctional design not only affords high sensitivity for early-stage aggregation but also provides morphological contrast for imaging, thereby bridging molecular sensing and histopathological examination.

Surface-Enhanced Raman Spectroscopy for Alzheimer's Disease Biomarker Detection publication trend

The graph below shows the total number of articles in surface-enhanced raman spectroscopy for alzheimer's disease biomarker detection across all publications each year (not limited to Nature Index journals).

Technical terms

Surface-Enhanced Raman Spectroscopy (SERS): A vibrational spectroscopy technique in which Raman scattering signals are amplified by metallic nanostructures, enabling detection of low-concentration analytes.

Localised Surface Plasmon Resonance (LSPR): Collective oscillation of conduction electrons in metal nanoparticles that generates intense electromagnetic fields at the nanoparticle surface, underpinning the SERS effect.

Amyloid-β (Aβ): Peptides derived from amyloid precursor protein that self-assemble into extracellular plaques, a neuropathological hallmark of Alzheimer’s disease.

Neurofibrillary Tangles (NFTs): Intracellular aggregates of hyperphosphorylated tau protein, forming filamentous inclusions in neurons and contributing to neurodegeneration.

Fibre-Enhanced Raman Spectroscopy (FERS): A variant of Raman spectroscopy in which photonic crystal or optical fibres deliver excitation light and collect scattered signals, often combined with SERS substrates for further enhancement.

References

1. SERS-Based Optical Nanobiosensors for the Detection of Alzheimer’s Disease. Biosensors (2023).
2. Hyperspectral Raman imaging of neuritic plaques and neurofibrillary tangles in brain tissue from Alzheimer’s disease patients. Scientific Reports (2017).
3. Bifunctional Fluorescent/Raman Nanoprobe for the Early Detection of Amyloid. Scientific Reports (2019).
4. Label-Free Detection and Self-Aggregation of Amyloid β‑Peptides Based on Plasmonic Effects Induced by Ag Nanoparticles: Implications in Alzheimer’s Disease Diagnosis. ACS Applied Nano Materials (2021).
5. Hollow core photonic crystal fiber-assisted Raman spectroscopy as a tool for the detection of Alzheimer’s disease biomarkers. Journal of Biomedical Optics (2020).