Japanese researchers have developed a new technique using Raman Spectroscopy that could help in early diagnosis of Alzheimer’s disease. Once approved, it could be a lifesaver as it will help in early intervention, before the condition worsens.
Their technique is an advanced version of an existing SERS (Surface-enhanced Raman spectroscopy) method used to identify biomolecules.
The improvement, by researchers at the RIKEN Centre for Advanced Photonics, called LI-SERS (Liquid Interface assisted SERS), takes the detection sensitivity several notches higher: up to a trillionth of the concentrations of Amyloid-beta plaque and DNA sequences.
Detecting such low concentrations of these compounds could help in the early-stage diagnosis of Alzheimer’s disease and viral infections.
SERS is a biophysical technique increasingly used in cell imaging and tumour therapy as it can detect trace amounts of biomolecules. Based on the scattering, scientists can infer the amount and structure down to a single molecule.
In the current study, published in Opto-Electronic Advances, the scientists have further improvised the conventional SERS method overcoming a major limitation — the requirement of chemicals to help attach the biomolecule onto the experimental surface.
Amyloid-beta protein is a key biomarker of Alzheimer’s disease and plays a crucial role in identifying disease progression. However, early-stage asymptomatic detection of the disease is incredibly challenging, and currently MRI and CT imaging methods have limitations to detect ultralow concentrations of the amyloid protein.
Checking this protein’s levels in body fluids may reveal the early onset and progression of Alzheimer’s, thus allowing for early therapeutic interventions which the present study has demonstrated.
The scientists added a microfluidic chip (a SIM card-like silicon chip with microtubes that carry fluid) to SERS to make the LI-SERS. Using this chip, they could directly bind the biomolecules to the surface and enhance the scattering and detect ultralow concentrations of large complex compounds like Amyloid protein.
“Notable features of the LI-SERS method, which include the ultrahigh sensitivity and versatility due to the self-immobilization of analyte molecules, will be beneficial for the early-stage diagnosis of disease such as viral infections and Alzheimer’s disease,” wrote the team led by Shi Bai, postdoctoral researcher, at the Riken Centre for Advanced Photonics in the paper.
The LI-SERS method also helps to differentiate healthy and altered DNA sequences for early detection of viral infections.
