An optofluidic water-jet waveguide on chip for fluorescence analysis is presented. A high-speed water stream produced by means of a microchannel acts at the same time as the solution to analyze and as the collecting optical waveguide. The absence of solid walls and the very optically smooth surface of the liquid stream permits a strong increase of the signal-to-noise ratio. The device layout allows a self-alignment direct coupling of a water-jet waveguide with a multimode optical fiber connected to the detector. The performances of the integrated system are tested on Cy5 water solutions. For a 4.5 mm long water-jet waveguide, the measured limit of detection (LOD) is 2.56 nM and filter-free detection is possible with an LOD of 6.11 nM.
© 2012 Optical Society of America
Original Manuscript: October 2, 2012
Revised Manuscript: November 9, 2012
Manuscript Accepted: November 13, 2012
Published: December 7, 2012
Vol. 8, Iss. 1 Virtual Journal for Biomedical Optics
Gianluca Persichetti, Genni Testa, and Romeo Bernini, "Optofluidic jet waveguide for laser-induced fluorescence spectroscopy," Opt. Lett. 37, 5115-5117 (2012)