What does ProteoStat® dye bind to and what is the mechanism of detection of protein aggregation?

The molecular rotor dye is non-fluorescent due to free rotation around a central carbon-carbon single bond separating different aromatic portions of the probes.

When the molecular rotor dye encounters protein aggregates, it blocks into the fibrils that hold beta sheets together and becomes highly fluorescent.   This is analogous to the fluorescence enhancement upon intercalation of ethidium bromide between the bases of nucleic acid.