LED-based sensor detects Alzheimer’s disease on a chip

Collaborative efforts from the University of Toronto Scarborough (Toronto, Canada) and Boston University (MA, USA) have resulted in the development of a sensing platform capable of monitoring the aggregation of the amyloid-β peptide (Aβ) that, when aggregated, leads to Alzheimer’s disease.

According to Kagan Kerman, lead author of the study and Professor at University of Toronto Scarborough, “We have successfully demonstrated a novel method for high-throughput screening of small molecules modulating Aβ growth and it provides a promising platform to facilitate the therapeutics discovery for Alzheimer’s disease.”

In this research an LED-interferometric reflectance imaging sensor was used to study the interaction of Aβ with small drug candidates. Consisting of a Si/SiO2 layered substrate, the sensing surface was spotted with Aβ peptide ‘seeds’ using a desktop spotting unit. The sensor was then incubated with drug candidates and Aβ oligomer solution, which led to differing levels of peptide aggregation. This research is the first example of this type of sensor that has been able to look at the interaction of Aβ with small drug candidates, by detecting the optical path length changes. In this study, green tea polyphenol epigallocatechin-3-gallate and zinc were used to demonstrate the peptide aggregation, as they are already known to have an effect on the Aβ peptide.

The ability to perform high-throughput measurements in real-time without the requirement of external labels is promising. Amyloid-forming proteins involved in the development of other neurodegenerative disease could also be studied with the technique, although more work is needed to be able to successfully identify possible therapeutics.

Source: Cheng XR, Daaboul GG, Ünlü MS et al. LED-based interferometric reflectance imaging sensor for the detection of amyloid-β aggregation. Analyst doi: 10.1039/C3AN01307C (Epub ahead of print) (2013).