Plasmonic enhancement of a whispering-gallery-mode biosensor for single nanoparticle detection
Abstract
We describe and demonstrate a physical mechanism that substantially enhances the label-free sensitivity of a whispering-gallery-mode biosensor for the detection of individual nanoparticles in aqueous solution. It involves the interaction of dielectric nanoparticle in an equatorial carousel orbit with a plasmonic nanoparticle bound at the microparticle's equator. As the dielectric particle parks to hot spots on the plasmonic particle we observe frequency shifts that are enhanced by a factor of 4, consistent with a simple reactive model. Once optimized the enhancement by this mechanism should exceed several orders of magnitude, putting individual protein within reach.
- Publication:
-
Applied Physics Letters
- Pub Date:
- June 2011
- DOI:
- 10.1063/1.3599584
- Bibcode:
- 2011ApPhL..98x3104S
- Keywords:
-
- biochemistry;
- bioelectric phenomena;
- biological effects of fields;
- biosensors;
- dielectric materials;
- microorganisms;
- nanoparticles;
- plasmonics;
- proteins;
- whispering gallery modes;
- 87.80.-y;
- 87.85.-d;
- 36.20.-r;
- 87.14.E-;
- 87.15.Pc;
- 87.15.N-;
- Biological techniques and instrumentation;
- biomedical engineering;
- Biomedical engineering;
- Macromolecules and polymer molecules;
- Proteins;
- Electronic and electrical properties;
- Properties of solutions of macromolecules