G-Quadruplex Lamellar Liquid Crystals Based on Deep Eutectic Solvents

Deep eutectic solvents (DESs) are relatively promising green solvents due to their low toxicity, high stability, and tunable structures. Despite their advantages, research on G-quadruplex ionic soft materials based on DESs remains scarce. Herein, we report the construction of G-quadruplex lamellar liquid crystals in DESs, specifically in choline chloride-ethylene glycol (ChCl-EG) mixtures. Our study may develop a solvent-mediated strategy and elucidate a formation mechanism driven by the oriented arrangement of solvent molecules, which plays a crucial role in the formation of lamellar structures. Dynamic borate esters were found to weaken inter-G-quadruplex interactions while enhancing G-quadruplex-solvent interactions. We investigated the effects of metal ions (K⁺, Na⁺, Ca²⁺, Sr²⁺, and Ba²⁺) and reactant concentrations on G-quadruplex assembly, revealing that metal ions control the stacking mode and regulate the mechanical properties of the resulting gels. The G-quadruplex lamellar liquid crystal exhibited high ionic conductivity (4.6 mS·cm^-1) and a wide electrochemical window (4.6 V). This work may advance the understanding of the G-quadruplex, establish DESs as versatile platforms for designing ionic soft materials, and open new avenues for applications in flexible electronics and energy storage.