Torsion-dependent fluorescence switching of amyloid-binding dye NIAD-4

- We investigated the molecular rotor property of NIAD-4, a novel amyloid-binding dye.
- We measured the viscosity dependence of fluorescence against the molecular rotor model.
- Calculations revealed the effect of each CC bond rotation on energy and fluorescence.
- NIAD-4 acts like a molecular rotor, perhaps in a lesser extent than other rotors.
- The origin of torsion-dependent fluorescence switching of NIAD-4 is discussed.