The pH responsibility of cationic charged dendrons, which were previously synthesized for DNA-sensing applications, was investigated. The first and second generation amide dendrons Cl and G2 formed hydrogels under basic conditions, but the hydrogel returned to the fluid state under acidic conditions; this process was completely reversible. In addition, the fluorescence of the diluted Cl, G2, and G3 solutions also showed a high sensitivity to the pH value.