Compact surface plasmon-enhanced fluorescence biochip

0396519 - ÚFE 2014 RIV US eng J - Journal Article
Toma, K. - Vala, Milan - Adam, Pavel - Homola, Jiří - Knoll, W. - Dostálek, J.
Compact surface plasmon-enhanced fluorescence biochip.
Optics Express. Roč. 21, č. 8 (2013), s. 10121-10132. ISSN 1094-4087
R&D Projects: GA ČR GBP205/12/G118
Institutional support: RVO:67985882
Keywords : Surface plasmons * Diffraction gratings * Biological sensing and sensors
Subject RIV: BH - Optics, Masers, Lasers
Impact factor: 3.525, year: 2013

A new concept of compact biochip for surface plasmon-enhanced fluorescence assays is reported. It takes advantage of the amplification of fluorescence signal through the coupling of fluorophore labels with confined and strongly enhanced field intensity of surface plasmons. In order to efficiently excite and collect the emitted fluorescence light via surface plasmons on a metallic sensor surface, (reverse) Kretschmann configuration is combined with diffractive optical elements embedded on the chip surface. These include a concentric relief grating for the imaging of highly directional surface plasmon-coupled emission to a detector. Additional linear grating is used for the generating of surface plasmons at the excitation wavelength on the sensor surface in order to increase the fluorescence excitation rate. The reported approach offers the increased intensity of fluorescence signal, reduced background, and compatibility with nanoimprint lithography for cost-effective preparation of sensor chip. The presented approach was implemented for biosensing in a model immunoassay experiment in which the limit of detection of 11 pM was achieved.
Permanent Link: http://hdl.handle.net/11104/0224280