Label-Free Surface-Enhanced Raman Spectroscopy Detection of Amyloid Beta on Silver Nanostructured Substrates for Alzheimer's Diagnosis.

Alzheimer's disease (AD) is a public health concern, for which an early diagnosis is essential. Biomass-derived carbon fibres with surface-decorated silver nanoparticles (Ag@CFs) have been utilized as surface enhanced raman spectroscopy (SERS) sensor platform for the detection of the amyloid beta Aβ (25-35) for the pre-diagnosis of Alzheimer's disease. Structural and morphological characterizations confirmed the distribution of plasmonic silver nanoparticles over the surface of carbon fibres. The SERS sensor performance of Ag@CFs was evaluated using rhodamine 6G, which showed an enhancement of the order of 10 which proved the effectiveness of the developed SERS sensor towards trace level detection of analyte. A range of amyloid beta concentrations, from 100uM to 10pM, have been analyzed as a proof-of concept for this study, showcasing the efficacy of the Ag@CFs based SERS sensor to detect trace level concentrations of amyloid beta, even as low as 10 pM. This investigation is a promising development in the field of AD diagnostics since it may turn out to be a non-invasive, economical and early diagnostic tool.