Optoelectronic detectors for flow analysis systems manufactured by means of rapid prototyping technology

Universal, customizable design of 3D printed photometric, and fluorometric flow-through detectors have been presented. The developed designs were fabricated with the use of the most affordable 3D printing technique, namely Fused Filament Fabrication, and require neither hardware nor tools to assemble. Numerous variants of detector geometries have also been presented. The designed parameters varied both in aperture (i.e., the internal diameter of the flow channel in an optical path) and in thickness of an absorbing layer. As expected, the geometry of the channels resulted in changes in the internal volumes. Two concepts of fluorometric detectors have also been described. The utility of all developed flow-through detectors was proven with the use of mechanized calibrations of both photometric and fluorometric experiments. Analytical parameters were characterized with the use of two model dyes: bromothymol blue and fluorescein for photometric and fluorometric experiments, respectively. The repeatability of the 3D printed vessels was found at 3.5–8.0% of the mean relative standard deviation (RSD), depending on the construction of the vessel, which is comparable to rather expensive commercially available flow cells. The compatibility of used 3D printing materials was also examined. For both variants of detection light emitting diodes were applied as light emitters. As the light detectors, both CCD spectrophotometers and light-emitting diodes were used.