Application of surface-enhanced Raman spectroscopy for detection of beta amyloid using nanoshells

Currently, no methods exist for the definitive diagnosis of AD premortem. beta-amyloid, the primary component of the senile plaques found in patients with this disease, is believed to play a role in its neurotoxicity. We are developing a nanoshell substrate, functionalized with sialic acid residues to mimic neuron cell surfaces, for the surface-enhanced Raman detection of beta-amyloid. It is our hope that this sensing mechanism will be able to detect the toxic form of beta-amyloid, with structural and concentration information, to aid in the diagnosis of AD and provide insight into the relationship between beta-amyloid and disease progression. We have been successfully able to functionalize the nanoshells with the sialic acid residues to allow for the specific binding of beta-amyloid to the substrate. We have also shown that a surface-enhanced Raman spectroscopy response using nanoshells is stable and concentration-dependent with detection into the picomolar range.