Strong fluorescence-signal gain with single-excitation-enhancing and emission-directing nanostructured diffraction grating.
A dielectric subwavelength diffraction grating structure is designed and fabricated in order to enhance fluorescence-based detection of biomolecules. Two separate phenomena, enhancement of the local energy densities of the excitation illumination and direction of the emitted signal toward the detector, are examined theoretically and experimentally. 530-fold enhancement of detected signal is achieved compared with the signal from flat surface. Also, changes in polarization and coherence properties of the fluorescent light are found to be remarkable.
University of Joensuu, Department of Physics and Mathematics, P.O. Box 111, FI-80101 Joensuu, Finland. petri.karvinen@joensuu.fi
Petri
P
Karvinen
Tarmo
T
Nuutinen
Jussi
J
Rahomäki
Outi
O
Hyvärinen
Pasi
P
Vahimaa
D015374:Biosensing Techniques; D004867:Equipment Design; D005453:Fluorescence; D005583:Fourier Analysis; D049452:Green Fluorescent Proteins / Q000737:chemistry; D007089:Image Enhancement; D008027:Light; D055095:Optics and Photonics; D012031:Refractometry / Q000379:methods*; D012822:Silicon Dioxide / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry
D049452:Green Fluorescent Proteins; C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium