Single-Molecule Detection using Plasmons in Metal Nanoparticles

Metal nanoparticles provide the possibility to detect single molecules without the need for labeling, enabling the direct detection of non-absorbing species [1]. A molecule that binds to receptors on the surface of a particle induces a change in the local refractive index that in turn results in a change of color due to a shift of the plasmon resonance [2,3]. This animation illustrates the real-time detection of plasmon shifts induced by molecules binding to functionalized single gold nanorods. The plasmon shifts are measured by monitoring scattering intensities of many particles simultaneously and in real-time. 
[1] P. Zijlstra, P.M.R. Paulo, M. Orrit, Nat. Nanotechnol. 2012, 7, 379-382 (
[2] P. Zijlstra, M. Orrit, Rep. Prog. Phys. 2011, 74, 106401 (
[3] P. Zijlstra, P.M.R. Paulo, K. Yu, Q-H Xu, M. Orrit, Angew. Chem. Int. Ed. 2012, 51, 8352-8355 (

Animation: ICMS Animation Studio
Audio: Studio Make