60

nanotimes News in Brief

Biophysics // Nanoparticle-based Protein Detection /

Optoplasmonic Superlenses © Text: APL / American Institute of Physics / PNAS © Image: Svetlana V. Boriskina

R

esearchers at Pennsylvania State University (USA), Boston University (USA), Wyss Institute

for Bioinspired Engineering, Harvard, Cambridge (USA), and Max Planck Institute for the Science of Light (Germany) demonstrate a biosensing ap- proach which, for the first time, combines the high sensitivity of whispering gallery modes (WGMs) with a metallic nanoparticle-based assay.

They provide a computational model based on gene- ralized Mie theory to explain the higher sensitivity of protein detection. They quantitatively analyze the binding of a model protein (i.e., Bovine Serum Albumin) to gold nanoparticles from high-Q WGM resonance frequency shifts, and fit the results to an adsorption isotherm, which agrees with the theo- retical predictions of a two-component adsorption model.

Miguel A. Santiago-Cordoba, Svetlana V. Boriskina, Frank Vollmer, and Melik C. Demirel: Nanoparticle-based protein detection by optical shift of a resonant microcavity, In: Applied Physics Letters, Vol. 99(2011), Issue 7, August 15, 2011, Article 073701 [3 pages], DOI:10.1063/1.3599706: http://dx.doi.org/10.1063/1.3599706

11-08 :: August 2011

Another related paper recently published in PNAS shows the advantages of the resonant hybrid opto- plasmonic elements as fluorescence sensors and quantum-optical networks components.

Svetlana Boriskina and Björn Reinhard (Department of Chemistry and the Photonics Center, Boston University, USA) introduce herein optoplasmonic superlenses that combine the capability of optical microcavities to insulate molecule-photon systems from decohering environmental effects with the superior light nanoconcentration properties of nanoantennas. The proposed structures provide significant enhancement of the emitter radiative rate