Scheme 1. (A) Structure of the molecular FRET pair (1), composed of bimane (blue) and NBD (green), connected with a short linker. Bimane, the energy donor, absorbs light at shorter wavelengths and transfers this energy to the acceptor (NBD), which in turn emits light in its unique spectral range. (B) Incorporating the acceptor into a polymer chain and utilizing 2 as cross-linker allows the optical read out of the folding state via the characteristic FRET spectrum.
