Analysis performed by this new biosensor could help identify inflammatory bowel diseases, cancer, and other chronic diseases, and contribute to influencing the best treatment options, a critical aspect of personalized medicine

Anatomic pathologists and clinical laboratories have long known that disease, as the saying goes, “is written in the blood.” How to spot the disease has been the challenge.

Now, researchers at Finland’s Aalto University have developed a cutting-edge plasmonic biosensor that uses the intense light absorption and reflective properties of plasmonic materials to discern refractive changes between healthy and diseased exosomes—even with the naked eye!

This opens the door to a plethora of non-invasive health tests similar to home pregnancy tests. Should such tests prove accurate and affordable, medical laboratories could have new tools in their fight to end chronic disease.

New Rules for Differentiating Healthy and Diseased Human Exosomes

The Aalto researchers produced the biosensor by depositing plasmonic metaparticles (hypothetical particles that always move faster than light, such as Tachyons) on a black metal surface capable of absorbing electromagnetic radiation. With it, abnormalities can be distinguished by the color generated when the plasmons impact the black surface.

“We exploited it as the basis of new design rules to differentiate diseased human serum exosomes from healthy ones in a simple manner with no need [for] any specialized equipment”, Dr. Abdou Elsharawy, PhD, Postdoctoral Researcher at Kiel University in Kiel, Germany, stated in an Aalto University news release.

 

Plasmonic Biosensor Aalto University

Researchers at Aalto University in Finland have developed a method for “visualizing the specular reflection color by a blackbody substrate. The carriers containing Ag nanoparticles [shown above] are covered with various dielectrics of AlN [aluminum nitride], SiO2 [silicon dioxide], and the composites thereof that are placed on a black background to enhance the reflectivity contrast of various colors at a normal angle of incidence.” This has resulted in a tool that medical laboratories could use to differentiate between healthy and diseased exosomes in human blood. (Photo and caption copyrights: Aalto University.)

 

Dr. Mady Elbahri, PhD, Professor, Nanochemistry and Nanoengineering, Department of Chemistry and Materials Science at Aalto University, indicated that there is no need to use sophisticated fabrication and patterning methods with the biosensor as bulk biodetection of samples can be seen with the naked eye.

“It is extraordinary that we can detect diseased exosomes by the naked eye. The conventional plasmonic biosensors are able to detect analytes solely at a molecular level. So far, the naked-eye detection of biosamples has been either rarely considered or unsuccessful,” Elbahri noted in the news release.

Exosomes Critical to Many Human Bodily Processes

Exosomes are cell-derived vesicles that are present in many and perhaps all eukaryotic fluids, including blood, urine, and cultured medium of cell cultures. These small bundles of material are released by the outer wall of a cell and contain everything from proteins to ribonucleic acid (RNA) and Messenger RNA (mRNA). They are important indicators of health conditions.

There is mounting evidence that exosomes have exclusive functions and perform a significant role in bodily processes like coagulation, intercellular signaling, and waste management.

Interest in the clinical applications of exosomes is increasing, along with their potential for use in prognosis, development of therapies, and as biomarkers for diseases. But, exosomes are rare and distinguishing them among all other elements located in bodily fluids has proven difficult.

Thus, the Aalto study has strong implications for clinical laboratories and anatomic pathology groups. More research and regulatory approval will be needed before use of this new tool comes to fruition. However, any method that accurately and inexpensively identifies chronic disease biomarkers will impact the medical laboratory and anatomic pathology professions and is worth watching

—JP Schlingman

Related Information:

Plasmonic Biosensors Enable Development of New Easy-to-use Health Tests

Plasmonic Biosensor to Detect Exosomes with Naked Eye

Plasmonic Metaparticles on a Blackbody Create Vivid Reflective Colors for Naked‐Eye Environmental and Clinical Biodetection

Plasmonic Biosensors