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Photonic crystal enhancement of a homogeneous fluorescent assay using submicron fluid channels fabricated by E‐jet patterning
Author(s) -
Tan Yafang,
Sutanto Erick,
Alleyne Andrew G.,
Cunningham Brian T.
Publication year - 2014
Publication title -
journal of biophotonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 66
eISSN - 1864-0648
pISSN - 1864-063X
DOI - 10.1002/jbio.201300158
Subject(s) - fluorescence , materials science , förster resonance energy transfer , photonics , photonic crystal , substrate (aquarium) , liquid crystal , optoelectronics , jet (fluid) , nanotechnology , optics , physics , oceanography , thermodynamics , geology
We demonstrate the enhancement of a liquid‐based homogenous fluorescence assay using the resonant electric fields from a photonic crystal (PC) surface. Because evanescent fields are confined to the liquid volume nearest to the photonic crystal, we developed a simple approach for integrating a PC fabricated on a silicon substrate within a fluid channel with submicron height, using electrohydrodynamic jet (e‐jet) printing of a light‐curable epoxy adhesive to define the fluid channel pattern. The PC is excited by a custom‐designed compact instrument that illuminates the PC with collimated light that precisely matches the resonant coupling condition when the PC is covered with aqueous media. Using a molecular beacon nucleic acid fluorescence resonant energy transfer (FRET) probe for a specific miRNA sequence, we demonstrate an 8× enhancement of the fluorescence emission signal, compared to performing the same assay without exciting resonance in the PC detecting a miRNA sequence at a concentration of 62 nM from a liquid volume of only ∼20 nL. The approach may be utilized for any liquid‐based fluorescence assay for applications in point‐of‐care diagnostics, environmental monitoring, or pathogen detection. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)