Lanthanide-DNA supramolecular hydrogels with tunable and responsive luminescence

Supramolecular DNA hydrogels have been synthesized based on the assembly of DNA building-blocks such as branched DNA and long DNA chains. The structures and functions of sole-module DNA hydrogels remain limitations. New methodologies by integrating hybrid components are desired to expand the synthesis of DNA hydrogel. Herein, we synthesized a Ln3+-containing luminescent supramolecular hydrogel by employing the coordination and electrostatic interactions between lanthanide ions (Tb3+ and Eu3+) and linear single-stranded DNA (ssDNA). Through the coordination between ssDNA and Ln3+, a series of luminescent supramolecular hydrogels were synthesized, among which the Tb-Gn/Tn and Eu-Tn hydrogels emitted the characteristic luminescence of Tb and Eu, respectively. The luminescent intensities of the hydrogels were adjusted by designing DNA sequences with programmable bases and chain lengths. Notably, the Tb/Eu co-doped luminescent supramolecular hydrogel displayed tunable luminescence from green to yellow by regulating the stoichiometric ratio of Tb/Eu. Moreover, the hydrogel had reversible luminescent stimulation responsiveness toward Ag+/L-Cys. We expected that the synthesis of Ln3+-containing luminescent supramolecular hydrogels enriched the strategies of the construction of DNA hydrogels, and promoted the development of stimuli-responsive supramolecular materials.