Photochemically Triggered and Autonomous Oscillatory pH‐Modulated Transient Assembly/Disassembly of DNA Microdroplet Coacervates

Abstract The assembly of pH‐responsive DNA‐based, phase‐separated microdroplets (MDs) coacervates, consisting of frameworks composed of Y‐shaped nucleic acid modules crosslinked by pH‐responsive strands, is introduced. The phase‐separated MDs reveal dynamic pH‐stimulated switchable or oscillatory transient depletion and reformation. In one system, a photoisomerizable merocyanine/spiropyran photoacid is used for the light‐induced pH switchable modulation of the reaction medium between the values pH=6.0–4.4. The dynamic transient photochemically‐induced switchable depletion/reformation of phase‐separated MDs, follows the rhythm of pH changes in solution. In a second system, the Landolt oscillatory reaction mixture pH 7.5→4.2→7.5 is applied to stimulate the oscillatory depletion/reformation of the MDs. The autonomous dynamic oscillation of the assembly/disassembly of the MDs follows the oscillating pH rhythm of the reaction medium.