On-chip cavity-enhanced absorption spectroscopy using a white light-emitting diode and polymer mirrors.

Cathy M Rushworth, Gareth Jones, Martin Fischlechner, Emma Walton, Hywel Morgan

Index: Lab Chip 15(3) , 711-7, (2015)

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Abstract

We have developed a disposable microfluidic chip with integrated cavity mirrors comprised of two pieces of 3M Vikuiti™ enhanced specular reflector II (ESRII) film, for performing cavity-enhanced absorption spectroscopy with a white light-emitting diode (LED). Compared to measurements made with a chip without cavity mirrors, the absorption path length is enhanced by a maximum factor of 28 at 544 nm, and the sensitivity is enhanced by approximately 5 times, enabling micromolar range detection limits to be achieved in an optical path length of only 50 μm.