Determination of Fluorescence Quantum Yields in Scattering Media

LAGORIO, MARÍA GABRIELA

Methods and Applications in Fluorescence

IOP publishing

Año: 2020 vol. 8

The fluorescence quantum yield is a measure of the efficiency of photon emission and quantifies theluminescent performance of a given sample. The determination of fluorescence quantum yields,particularly in scattering media, is relevant in the areas of materials science, technology and photonics.It is equally crucial when studying fluorescent bioanalytical probes and biological systems either formedical applications, physiological analyses or the interpretation of optical signals in nature. This typeof determination represents a challenge since light scattering introduces an appreciable complexity inthe measurements. Hence, the use of experimentally accurate methods and the understanding of theirbasis and principles is indispensable for obtaining reliable results. In addition, light re-absorptionprocesses are usually very significant in these systems and the experimental quantum yields normally differ from the true quantum yields of the fluorophore. The first purpose of this work is to provide aclear and comprehensive compilation of the various optical methods that can be used for the determination of quantum yields in scattering media. A second purpose is to present the correction models to account for light re-absorption processes, applicable in each case. The advantages and disadvantages of each methodology are comparatively discussed, the difference between experimental and true quantum yield is clarified and it is explained which should be used depending on the case.Several examples previously published in literature are illustrated. The methods presented here areadequate for the study of very diverse samples such as suspensions, solid powders, films, animal tissues and even plant material.