Accounting for Secondary Inner Filter Effect in Fluorescence Spectra from Solid Samples

Fluorescence experiments at high fluorophore concentrations or in solid state have biological relevance and application potential in devices. Inner filter effect, arising from reabsorption of emitted photons, is the simplest of several factors that complicate the emission in these systems. This effect is prominent, especially for systems with small Stokes shift between absorption and emission. Solid state ‘dilution’ of a fluorophore with an optically transparent, non-interfering substance can significantly minimize this effect. This has been shown in the present study, using salophen as a fluorophore and NaCl as the dilutant. The general applicability of this method is tested with three more fluorophores.