Amyloid-based diseases, such as amyloid light-chain amyloidosis, are characterized by misfolding of proteins and their deposition as amyloids in tissues. As prognosis is usually poor, patients suffering from these illnesses can benefit from improved detection, monitoring, and treatment techniques. The use of nanoparticles to diagnose and treat biological targets has been extensively studied, including as a potential marker for Alzheimer’s disease, but not in the context of amyloidosis. Although curcumin is a known amyloid-binding molecule, vanillin attachment to amyloids has not been proposed or tested in the past. Our study focuses on iron oxide and gold nanoparticles, functionalized with curcumin and vanillin, as potential agents for amyloid specific binding. These nanoparticles are designed to have high visibility in computed tomography or magnetic resonance imaging and can therefore facilitate improved imaging and monitoring of amyloids. Amyloid fibers and plaques were prepared from insulin, and the successful binding of the nanoparticles to the amyloids was demonstrated using optical, fluorescence, and transmission electron microscopy. The nanoparticles did not bind to amyloids placed in cell-culture models, suggesting good specificity.
Significance: Alzheimer’s disease (AD) is an irreversible and progressive disorder that damages brain cells and impairs the cognitive abilities of the affected. Developing a sensitive and cost-effective method to detect Alzheimer’s biomarkers appears vital in both a diagnostic and therapeutic perspective.
Aim: Our goal is to develop a sensitive and reliable tool for detection of amyloid β (1-42) peptide (Aβ42), a major AD biomarker, using fiber-enhanced Raman spectroscopy (FERS).
Approach: A hollow core photonic crystal fiber (HCPCF) was integrated with a conventional Raman spectroscopic setup to perform FERS measurements. FERS was then coupled with surface-enhanced Raman spectroscopy (SERS) to further amplify the Raman signal thanks to a combined FERS-SERS assay.
Results: A minimum 20-fold enhancement of the Raman signal of Aβ42 as compared to a conventional Raman spectroscopy scheme was observed using the HCPCF-based light delivery system. The signal was further boosted by decorating the fiber core with gold bipyramids generating an additional SERS effect, resulting in an overall 200 times amplification.
Conclusions: The results demonstrate that the use of an HCPCF-based platform can provide sharp and intense Raman signals of Aβ42, in turn paving the way toward the development of a sensitive label-free detection tool for early diagnosis of AD.
Alzheimer’s disease (AD) is an irreversible progressive disease that damages the brain cell and affects the cognitive abilities. Hence an early detection of AD biomarkers is vital for the drug treatment. Considering this, we developed a sensitive and reliable sensing tool based on fiber-enhanced Raman spectroscopic technique for the detection of AD biomarkers. The fiber-enhanced Raman measurements were performed using a hollow core photonic crystal fiber, and a comparison of Raman spectra of samples in a conventional cuvette and with the fiber was carried out. The results showed a high enhancement of Raman signal of samples measured with a fiber compared to the measurements carried out in the cuvette.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.