Molecular doping of nucleic acids into light emitting crystals driven by multisite-intermolecular interaction
Woo Hyuk Jung, Jin Hyuk Park, Seokho Kim, Chunzhi Cui, Dong June Ahn
Abstract
Abstract We reveal the fundamental understanding of molecular doping of DNAs into organic semiconducting tris (8-hydroxyquinoline) aluminum (Alq 3 ) crystals by varying types and numbers of purines and pyrimidines constituting DNA. Electrostatic, hydrogen bonding, and π-π stacking interactions between Alq 3 and DNAs are the major factors affecting the molecular doping. Longer DNAs induce a higher degree of doping due to electrostatic interactions between phosphate backbone and Alq 3 . Among four bases, single thymine bases induce the multisite interactions of π-π stacking and hydrogen bonding with single Alq 3 , occurring within a probability of 4.37%. In contrast, single adenine bases form multisite interactions, within lower probability (1.93%), with two-neighboring Alq 3 . These multisite interactions facilitate the molecular doping into Alq 3 particles compared to cytosines or guanines only forming π-π stacking. Thus, photoluminescence and optical waveguide phenomena of crystals were successfully tailored. This discovery should deepen our fundamental understanding of incorporating DNAs into organic semiconducting crystals.