On-chip absorption measurements using an integrated waveguide.

Bryan G Splawn; Fred E Lytle

doi:10.1007/s00216-002-1316-9

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On-chip absorption measurements using an integrated waveguide.

Bryan G Splawn·Fred E Lytle

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Abstract

Square hollow waveguides are used to integrate measurement of absorption with chip-based electrophoresis. The 50x50 microm liquid channel and 50x50 microm waveguide are etched as a negative pattern into a silicon master and replicated as a positive in poly-dimethylsiloxane (PDMS). The uniform refractive index of the chip prevents guiding by total internal reflection. Instead, light at 488 nm is guided by reflection at the air-PDMS interface. The waveguide has a 60% efficiency over a distance of 3.2 cm. Separation of fluorescein and the dye BODIPY is demonstrated. A detection limit (S/N=3) of 200 microM fluorescein is obtained using a 50 microm pathlength and a simple photocell detector.

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Absorption Boron Compounds Calibration Dimethylpolysiloxanes Electrochemistry Electrophoresis, Capillary Equipment Design Fluorescein Fluorescence Microscopy, Electron, Scanning Miniaturization Refractometry Reproducibility of Results Sensitivity and Specificity Silicon Journal Article Research Support, U.S. Gov't, P.H.S.

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Bryan G Splawn, Fred E Lytle. 2002-06-21. On-chip absorption measurements using an integrated waveguide.. https://doi.org/10.1007/s00216-002-1316-9

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