Fluorescence emission angular dependence on a nanostructured plasmonic grating

Plasmonic gratings provide an advantageous platform for fluorescence sensing due to their compatibility with functionalization techniques, imaging detection, and the potential for signal enhancement. Among traditional fluorescence detection methods, microscopes are commonly used tools. The interaction between dye fluorescence processes and the plasmonic modes of the grating strongly depends on the measurement configuration and is influenced by the dispersion and spectral characteristics of the plasmonic modes. In our study, we investigated the angular behavior of the fluorescence emission from ATTO700 dye by varying the collection angle using a standard optical microscope coupled with a spectrometer. Our results show a clear dependence of fluorescence emission in terms of spectral shape on the collection angle that can be attributed to plasmonic mode dispersion.