Selectively aggregating natural ligands into efficient AIEgens by human telomeric duplex-G-quadruplex junction

Abstract

DNA structures with potentials to concurrently recruit multiple ligands are promising in pharmaceutic and sensing applications by concentrating them in a local environment. Herein, we found that human telomeric G-quadruplex (htG4) structures with a junction can selectively aggregate a natural ligand of tetrahydropalmatine (THP) into AIEgens. The htG4 monomer favors formation of THP dimer emitting at ~525 nm. In addition, only the hybrid htG4 folding supports formation of the emissive THP dimer. However, overhanging a duplex beyond the 5′ end of the hybrid htG4 structure prefer to form THP J-aggregates with member molecularity being more than two. It is demonstrated that the junction between duplex and the hybrid htG4 structure is responsible for formation of the THP J-aggregates, as confirmed by the fact that the pairing state of the junction affects the J-aggregates molecularity. Nevertheless, such J-aggregates can’t be grown at the junction of two tandem htG4s. Therefore, G4-initiated ligand aggregation (GILA) for natural compounds provides a new way to design pharmaceuticals and sensors with a high local concentration at the site of interest. Our work first demonstrates the AP site programmed chirality regulation of G4-grown dye assemblies and will find wide applications in chiral devices.