The state of water molecules induces changes in the topologies and interactions of G-quadruplex DNA aptamers in hydrated ionic liquid

•Hydrated [ch][dhp] effectively dissolves G-quadruplex DNA aptamers while maintaining their structure and binding affinity.•Water content variations in hydrated [ch][dhp] affect the topology and binding abilities of dissolved aptamers.•Enhanced thermal stability of G-quadruplex structures was observed in hydrated [ch][dhp].