A versatile liquid-core/liquid-twin-cladding waveguide micro flow cell fabricated by rapid prototyping

Abstract

In this paper we present the design and operation of a micro flow cell comprising a liquid-core/liquid-twin-cladding waveguide for on-chip fluorescence spectroscopy based on evanescent field illumination. The application of an inner (sample) and outer cladding stream minimizes the sample volume for optical measurements and ensures the analyte position in the evanescent field for excitation at the core/cladding interface. The fiber-chip-coupled laser light is guided by the fluidic waveguide providing a uniform excitation along the analysis channel. Fluorescence intensity measurements of different sample solutions were conducted to illustrate the operational quality. The fluidics device is fabricated by laser microstereolithography in 1.5 h.