Skip to main content
. 2015 May 13;6(7):4190–4195. doi: 10.1039/c5sc00594a

Fig. 1. (A) Synthesis of the DNA chains undergoing pH-stimulated hydrogel formation and dissociation. Formation of the hydrogel is triggered at pH = 7.4 through the crosslinking of the polymer chains by duplex Watson–Crick interactions. The separation of the hydrogel is triggered at pH = 5.0 using Hoogsteen triplex interactions that separate the bridging units. By reversible pH triggers between the values 7.4 and 5.0, the system undergoes cyclic transitions between the hydrogel and solution phases. (B) Photographs of the solution phase of the system at pH = 5.0, and the hydrogel phase at pH = 7.4. The pH-stimulated transition of the hydrogel to the liquid phase proceeds within a time interval of <1 minute via shaking. (C) Rheology studies following the pH-switchable storage moduli, G′, and loss moduli, G′′, upon cyclic the pH of the system between the values pH = 5.0 and pH = 7.4. (D) SEM image of the Au/Pd coated (3)/(4) hydrogel.

Fig. 1