Angular study of laser induced fluorescence emission of hybrid media based on Stern-Volmer formalism

Abstract

Here, the quenching process of Rhodamine B fluorophores coupled with Titanium dioxide (TiO2) nanoparticles (NPs) and Graphene oxide (GO) nano structures is empirically investigated during the laser induced fluorescence (LIF) events in various detection angles. According to Stern-Volmer formalism, the slope of Stern-Volmer graph is strongly dependent on the angular orientation of the detector, mainly because of the alteration in active volume. The corresponding spectral shift lucidly changes due to the anisotropy of the re-absorption events while the single and multiple scattering simultaneously take place, particularly at dense suspensions. The fluorescence Stokes shift of RdB molecules, as well as the effect of non-homogeneous population of the exited/unexcited molecules are taken into account as dominant factors during the measurements. However, the fluorescence trapping becomes more effective in dense suspension and larger detection angles.