Quantifying fluorescent compounds in turbid media such as tissue is made difficult by the effects of multiple scattering and absorption of the excitation and emission light. The approach that we used was to measure fluorescence using a single 200-µm optical fiber as both the illumination source and the detector. Fluorescence of aluminum phthalocyanine tetrasulfonate (AlPcS<sub>4</sub>) was measured over a wide range of fluorophore concentrations and optical properties in tissue-simulating phantoms. A root-mean-square accuracy of 10.6% in AlPcS<sub>4</sub> concentration was attainable when fluorescence was measured either interstitially or at the phantom surface. The individual effects of scattering, absorption, and the scattering phase function on the fluorescence signal were also studied by experiments and Monte Carlo simulations.
© 2003 Optical Society of America
(170.3890) Medical optics and biotechnology : Medical optics instrumentation
(170.5180) Medical optics and biotechnology : Photodynamic therapy
(170.6280) Medical optics and biotechnology : Spectroscopy, fluorescence and luminescence
(170.7050) Medical optics and biotechnology : Turbid media
Kevin R. Diamond, Michael S. Patterson, and Thomas J. Farrell, "Quantification of Fluorophore Concentration in Tissue-Simulating Media by Fluorescence Measurements with a Single Optical Fiber," Appl. Opt. 42, 2436-2442 (2003)