Extracellular vesicle (EV) and exosome research at IKMB

December 29, 2017 - 09:00


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

Abdou Elsharawy (IKMB), in a collaboration with Prof. M. Elbahri (Nanochemistry and Nanoengineering, Aalto University, Finland) and his group and Dr. Christian Röder (Institute of Experimental Tumor Research , University Hospital Schleswig-Holstein (UKSH), published this month an innovative application of using “refractive index changes of plasmonic metaparticles” to enable naked-eye biodetection and discrimination between serum exosomes of healthy individuals and patients with inflammatory bowel disease.

The study has been recently published in Advanced Materials 2017 Dec 7. PMID: 29215167

See also the news on Clinical Lab Products.


Plasmonic dipoles are famous for their strong absorptivity rather than their reflectivity. Here, the as-yet unknown specular reflection and the Brewster effect of ultrafine plasmonic dipoles, metaparticles, are introduced and exploited as the basis of new design rules for advanced applications. A configuration of “Plasmonic metaparticles on a blackbody” is demonstrated and utilized for the design of a tailored perfect-colored absorber and for visual detection of environmental dielectrics that is not readily done by extinction plasmonics. Moreover, the Plasmonic Brewster Wavelength (PBW) effect is introduced as a new platform for the naked-eye and bulk biodetection of analytes. The technique operates based on slight changes of molecular polarizability which is not detectable via conventional plasmon resonance techniques. As a specific highlight, the clinical applicability of the PBW method is demonstrated while addressing the transduction plasmonic techniques’ challenge in detection of bulk refractive index changes of the healthy and diseased human serum exosomes. Finally, the sputtering-based fabrication method used here is simple, inexpensive, and scalable, and does not require the sophisticated patterning approach of lithography or precise alignment of light coupling for the biodetection.