University of Illinois

Sru Biosystems, Inc.

Anusha Pokhriyal

Brian T Cunningham

Meng Lu

Vikram Chaudhery

Stephen C Shulz

Sherine George

A silicon-based photonic crystal includes a silicon substrate, a first dielectric with a grating structure formed therein, and a second dielectric with a higher index of refraction that covers at least a portion of the grating structure. The first dielectric can be formed on the silicon substrate, or a Fabry-Perot optical cavity can be formed between the silicon substrate and the first dielectric. An instrument can excite a fluorophore coupled to the photonic crystal by focusing collimated incident light that includes the fluorophore's excitation wavelength to a focal line on the surface of the photonic crystal such that the focal line is substantially parallel to the grating direction and can detect fluorescence radiation emitted by the fluorophore in response to the incident light. To provide for fluorescence enhancement, the excitation wavelength and/or emission wavelength of the fluorophore can couple to an optical resonance of the photonic crystal.

Silicon-based photonic crystal fluorescence enhancement and laser line scanning instrument

A photonic crystal substrate exhibiting resonant enhancement of multiple fluorophores has been demonstrated. The device, which can be fabricated uniformly from plastic materials over a &#x2dc;3&#xd7;5 insurface area by nanoreplica molding, features a 1-D periodic grating structure which utilizes two distinct resonant modes to enhance electric field stimulation of a first dye excited by a first laser (e.g., &#x3bb;=632.8 nm laser exciting cyanine-5) and a second dye excited by a second laser (e.g., &#x3bb;=532 nm laser exciting cyanine-3). The first and second lasers could be replaced by a single variable wavelength (tunable) laser. Resonant coupling of the laser excitation to the photonic crystal surface is obtained for each wavelength at a distinct incident angle &#x3b8;. The photonic crystal is capable of amplifying the output of any fluorescent dye with an excitation wavelength in a given wavelength range (e.g., the range 532 nm&#x3c;&#x3bb;&#x3c;660 nm) by selection of an appropriate incident angle. The device can be used for biological assays that utilize multiple fluorescent dyes within a single imaged area, such as gene expression microarrays.

Multi-color fluorescence enhancement from a photonic crystal surface

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Mountain View, CA, United States of America

Anusha Pokhriyal