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Updated: Aug 25, 2026

Highly Sensitive and Rapid Fluorescence Detection with a Portable FRET Analyzer
Published on: October 1, 2016
A portable absorption-fluorometer for detection of organic substances in fluids
K H Mittenzwey1, G Sinn, R Hiersigk
1Gesellschaft für Mess- und Systemtechnik mbH, Rudower Chaussee 5, D-12489, Berlin, Germany.
Abstract:
Using the method of multipath-saturation fluorescence, which considers both fluorescent as well as nonfluorescent substances, the total absorption coefficient can be determined with high sensitivity. This new fluorescence method is appropriate, e.g. for in-situ applications. Thus a portable absorption-fluorometer has been constructed. The main part of the device is a multireflection cell based on a design of Herriott with a 1 cm quartz-cuvette. Two pairs of spherical dielectric mirrors are used to realize the multireflection of the excitation radiation in the UV and blue spectral range. The combination of a cylindrical and a convace mirror leads to a long pathway of the excitation radiation and, thus, to a full absorption by the fluid. A first experiment has been performed with drinking water samples defined polluted by non-fluorescent p-nitrophenol and 2-nitroaniline. Based on the method of multipath-saturation fluorescence a good correlation to the substance concentration was achieved, whereas the conventional absorption failed.
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