Industry News
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A spectrometer aided researchers in the examination of potential Alzheimer’s biomarker levels in body fluids.
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Advances in spectrometry have enabled scientists to observe molecules believed to be associated with Alzheimer’s disease. Researchers in the departments of chemistry and neurobiology and physiology at Northwestern University (Evanston, IL, USA) used an Ocean Optics Inc. (Dunedin, FL, USA) spectrometer for the analysis of spectral changes in nanoparticles.
Research reveals that significantly elevated levels of tiny toxic proteins called amyloid-derived diffusible ligands (ADDLs) are present in autopsied brain samples from Alzheimer’s patients. Authors of the study state that evidence strongly suggests a correlation between amyloid-b and the development of the disease. Furthermore, reports indicate that ADDLs cause neurological dysfunction related to memory. Such discoveries have led many experts to believe that monitoring the behavior of ADDLs in body fluid could aid in the eventual diagnosis of the disease.
In order to detect the biomarkers, researchers developed a system consisting of a nanoparticle array used in conjunction with a fibre-optically coupled spectrometer. The nanosensor was rooted in triangular silver nanoparticles coated with ADDL-specific antibodies. Antibodies then bound to ADDL molecules found in the samples, inducing the spectral properties of the nanoparticles to alter. The resulting concentration of ADDLs was evaluated using the spectrometer.
“Although changes in extinction that occur within the visible range of wavelengths can often be viewed by the eye, the spectrometer provides a quantitative measure of spectral shifts as a function of binding events between antibodies and antigens at the particle surface,” says Paige Hall, a Northwestern PhD candidate involved in the study. “The high resolution of the spectrometer also lowers the limit of detection of the localized surface plasmon resonance (LSPR) sensor, making it more compatible for clinical use.”
The S2000 UV/VIS collected macroscale UV/VIS extinction measurements, which are the sum of adsorbed and scattered light. As a result, researchers were able to compare samples containing elevated ADDL presence in Alzheimer’s patients with ones from a control group.
“Our studies have demonstrated that the LSPR sensor can distinguish differences in amyloid-b levels between healthy individuals and individuals with Alzheimer’s disease,” Hall says. “As there is currently no molecular basis of detection for Alzheimer’s disease, the LSPR sensor could potentially allow earlier and more-accurate diagnosis, paving the way to better treatment for those who suffer from Alzheimer’s.”
For more information about the spectrometer used in the study and related instruments, contact Ocean Optics Inc., 830 Douglas Ave., Dunedin, FL, 34698 USA; phone: +1 727 7332447; fax: +1 727 7333962; Internet: www.oceanoptics.com.
