Fluorescence energy transfer efficiency in labeled yeast cytochrome c: a rapid screen for ion biocompatibility in aqueous ionic liquids

A fluorescence energy transfer de-quenching'' assay was implemented to follow the equilibrium unfolding behaviour of site-specific tetramethylrhodamine-labelled yeast cytochrome c in aqueous ionic liquid solutions; additionally, this approach offers the prospect of naked eye screening for biocompatible ion combinations in hydrated ionic liquids.