Exploiting the light–metal interaction for biomolecular sensing and imaging

Institute of Physics, University of Münster, 48149 Münster, Germany.
Quarterly Reviews of Biophysics (Impact Factor: 7.81). 05/2012; 45(2):209-55. DOI: 10.1017/S0033583512000042
Source: PubMed


The ability of metal surfaces and nanostructures to localize and enhance optical fields is the primary reason for their application in biosensing and imaging. Local field enhancement boosts the signal-to-noise ratio in measurements and provides the possibility of imaging with resolutions significantly better than the diffraction limit. In fluorescence imaging, local field enhancement leads to improved brightness of molecular emission and to higher detection sensitivity and better discrimination. We review the principles of plasmonic fluorescence enhancement and discuss applications ranging from biosensing to bioimaging.

1 Follower
17 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: A novel and systematic method for sensitive detection of Fe3 + ions in aqueous media using gold nanorods (Au NRs) as nanosensors is presented. One of the most rousing achievements is the detection limit which is found to be 100 ppb for Fe3 + ions. The whole procedure takes not more than 10 min which uses surfactant cetyltrimethylammonium bromide (CTAB) capped seed instead of a citrate to overcome the formation of spherical particles in excess amount along with rods. This work also presents a low cost and effective solution for separation of seed mediated grown Au NRs from co-produced spherical nanoparticles formed in solution. The characterization of nanomaterials and interaction of Fe3 + ions with sensor material was studied by UV-vis spectrophotometer to determine optical properties, while scanning electron microscope (SEM) and transmission electron microscope (TEM) was used to determine morphology. The interaction of Fe3 + ions with Au NRs was investigated by surface-enhanced Raman scattering (SERS) using crystal violet (CV) molecule. The aspect ratio (length/diameter) of Au NRs was controlled by the amount of surfactant added. The method reported herein is a simple way to detect and determine Fe3 + ions in aqueous solution at the ppb levels and easily applicable for monitoring of Fe3 + ions in water sample.
    Microchemical Journal 11/2013; 113. DOI:10.1016/j.microc.2013.11.004 · 2.75 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Surface enhanced spectroscopy encompasses a broad field of linear and nonlinear optical techniques that arose with the discovery of the surface-enhanced Raman scattering (SERS) effect. SERS enabled ultrasensitive and single molecule detection with molecular fingerprint specificity, opening the door for a large variety of chemical sensing applications. Basically, from the beginning it was realized that the necessary condition for SERS to be observed was the presence of a metallic nanostructure, and with this condition, the optical enhancement found a home in the field of plasmonics. Although plasmonic practitioners claim that SERS is "the most spectacular application of plasmonics", perhaps it is more appropriate to say that the spectacular development of plasmonics is due to SERS. Here is a brief recollection from surface enhanced spectroscopy to plasmon enhanced spectroscopy.
    Physical Chemistry Chemical Physics 03/2013; 15(15). DOI:10.1039/c3cp44103b · 4.49 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Recently, plexcitonic systems consisting of a plasmonic nanoshell or a core covered by an excitonic shell are engineered. Such systems hold promise for tunable nanophotonic devices for imaging, chemical sensing, and resonance energy transfer. Their plasmonic response is grasped well, while understanding of their excitonic response remains to be improved. To this end we have developed a methodology in which the functionalities of the dispersive properties of the spherical shell and the nanoenvironment in tuning the optical response are clearly separated. Using this methodology, we have studied the response of the Lorentzian/excitonic nanoshells with optically inactive core and embedding medium and compared with the well-known properties of the Drude/plasmonics nanoshells. Contrary to Drude nanoshells exhibiting a resonance pair red-shifted with respect to the bulk, Lorentzian nanoshells are identified by a resonance pair blue-shifted with respect to the in-solution excitonic resonance. While the Drude red-shifting is more effective at increasing dielectric constants (core, shell and embedding medium), the Lorentzian blue-shifting is governed by the excitonic strength and is suppressed at increasing dielectric constants. The implications of the results for manipulating the optical response of plexcitonic systems are briefly discussed.
    The Journal of Physical Chemistry B 05/2013; 117(38). DOI:10.1021/jp402109p · 3.30 Impact Factor
Show more


17 Reads
Available from