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arXiv · 1410.8463

Differentiating surface and bulk interactions in nanoplasmonic interferometric sensor arrays

Beibei Zeng·Yongkang Gao·Filbert J. Bartoli
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Abstract

Detecting specific target analytes and differentiating them from interfering background effects is a crucial but challenging task in complex multi-component solutions commonly encountered in environmental, chemical, biological, and medical sensing applications. Here we present a simple nanoplasmonic interferometric sensor platform that can differentiate the adsorption of a thin protein layer on the sensor surface (surface effects) from bulk refractive index changes (interfering background effects) at a single sensing spot, exploiting the different penetration depths of multiple propagating surface plasmon polaritons excited in the ring-hole nanostructures. A monolayer of bovine serum albumin (BSA) molecules with an effective thickness of 1.91nm is detected and differentiated from a 10-3 change in the bulk refractive index unit of the solution. The noise level of the retrieved real-time sensor output compares favorably with traditional prism-based surface plasmon resonance sensors, but is achieved using a significantly simpler collinear transmission geometry and a miniaturized sensor footprint.

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Beibei Zeng, Yongkang Gao, Filbert J. Bartoli. 2014-10-30. Differentiating surface and bulk interactions in nanoplasmonic interferometric sensor arrays. https://doi.org/10.1039/c4nr05495d

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