Fig. 4

Chiral environment of the cation-binding sites in PBTA^BA nanoribbons. a Schematic representation of the binding of methylene blue (MB) onto PBTA^BA at its carboxylate units via an electrostatic interaction. b, c Circular dichroism (CD, b) and circularly polarized luminescence (CPL, λ_ext = 290 nm, c) spectra at 25 °C of DMF/water (7/3, v/v; 1 mL) suspensions of (−)-PBTA^BA (blue) and (+)-PBTA^BA (pink) ([BTA^BA] = 5.3 mM, Fig. 2d, e). d, e CD (d) and CPL (λ_ext = 550 nm, e) spectra at 25 °C of DMF/water (7/3, v/v; 1 mL) suspensions of (−)-PBTA^BA (blue) and (+)-PBTA^BA (pink) ([BTA^BA] = 5.3 mM) containing MB ([MB]/[BTA^BA] = 20%). Source data are provided as a Source Data file