Molecular plasmonics for biology and nanomedicine

California NanoSystems Institute, University of California, Los Angeles, CA 90095, USA.
Nanomedicine (Impact Factor: 5.41). 05/2012; 7(5):751-70. DOI: 10.2217/nnm.12.30
Source: PubMed

ABSTRACT The optical excitation of surface plasmons in metal nanoparticles leads to nanoscale spatial confinement of electromagnetic fields. The confined electromagnetic fields can generate intense, localized thermal energy and large near-field optical forces. The interaction between these effects and nearby molecules has led to the emerging field known as molecular plasmonics. Recent advances in molecular plasmonics have enabled novel optical materials and devices with applications in biology and nanomedicine. In this article, we categorize three main types of interactions between molecules and surface plasmons: optical, thermal and mechanical. Within the scope of each type of interaction, we will review applications of molecular plasmonics in biology and nanomedicine. We include a wide range of applications that involve sensing, spectral analysis, imaging, delivery, manipulation and heating of molecules, biomolecules or cells using plasmonic effects. We also briefly describe the physical principles of molecular plasmonics and progress in the nanofabrication, surface functionalization and bioconjugation of metal nanoparticles.

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    • "Nanostructures of materials having free conduction electrons (in particular gold, silver) display resonances at optical frequencies commonly referred to as plasmonic resonances[2]. One particularly versatile type of plasmonic material are colloidal gold nanoparticles, that can be dressed with a nanoscale coating of organic material[3], which can make their plasmonic resonance sensitive to the surrounding biomolecular environment[4], [5], [6], [7]. Such analyte-sensitive gold nanoparticles (Fig. 1) can be used as optical transducers of biomolecular signals. "
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    Journal of Physical Chemistry Letters 09/2012; 3(17-17):2388-2394. DOI:10.1021/jz300968m · 7.46 Impact Factor
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    ABSTRACT: We present a pseudoparticle nonequilibrium Green function formalism as a tool to study the coupling between plasmons and excitons in nonequilibrium molecular junctions. The formalism treats plasmon-exciton couplings and intramolecular interactions exactly and is shown to be especially convenient for exploration of plasmonic absorption spectrum of plexitonic systems, where combined electron and energy transfers play an important role. We demonstrate the sensitivity of the molecule-plasmon Fano resonance to junction bias and intramolecular interactions (Coulomb repulsion and intramolecular exciton coupling) and compare our predictions for nonlinear optical effects to previous studies. Our study opens a way to deal with strongly interacting plasmon-exciton systems in nonequilibrium molecular devices.
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