Dark-field spectral imaging microscope for localized surface plasmon resonance-based biosensing

Sang-Youp Yim; Jin-Ho Park; Min-Gon Kim

doi:10.1117/12.2189441

8 July 2015 Dark-field spectral imaging microscope for localized surface plasmon resonance-based biosensing

Sang-Youp Yim, Jin-Ho Park, Min-Gon Kim

Proceedings Volume 9523, International Conference on Nano-Bio Sensing, Imaging, and Spectroscopy 2015; 952307 (2015) https://doi.org/10.1117/12.2189441
Event: International Conference on Nano-Bio Sensing, Imaging, and Spectroscopy 2015, 2015, Jeju, Korea, Republic of

Abstract

Localized surface plasmon resonance (LSPR) of metal nanoparticles makes red-shift of extinction wavelength with an increase in the refractive index at the surface of the metal nanoparticles. Since biomolecules bound to the metal nanoparticle’s surface induce refractive index change, biosensing based on LSPR effect can be possible by monitoring scattering or absorption spectrum changes. Generally, however, conventional method detects ensemble averaged LSPR signal of a huge number of metal nanoparticles. Here, we have constructed a dark-field spectral imaging microscope in order to monitor the scattering spectra of individual metal nanoparticles, simultaneously. Gold nanorod (GNR) and aptamer are employed to detect ochratoxin A (OTA) related to a carcinogenic illness. An aptamer-target binding mechanism promotes wavelength shift of extinction spectra due to refractive index change within sensing volume of GNR by structural change of aptamer. A number of GNRs can be identified in a dark-field LSPR image, simultaneously. A typical spectrum of a GNR exhibits red-shift after target binding of molecules and OTA detection is extended to the very low concentration of 1 pM level.

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Sang-Youp Yim, Jin-Ho Park, and Min-Gon Kim "Dark-field spectral imaging microscope for localized surface plasmon resonance-based biosensing", Proc. SPIE 9523, International Conference on Nano-Bio Sensing, Imaging, and Spectroscopy 2015, 952307 (8 July 2015); https://doi.org/10.1117/12.2189441

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