Bioinspired Programmable Engineering of a Color-Change Biointerface based on Dual-Stimulation Regulation.

Some animals can change their skin colors in response to multiple stimuli by controlling the skin pigment cell or guanine crystals. An artificial color-change interface inspired by these natural properties has been developed; the interface responded to different types of stimuli, however, is still rare. Herein, we design a color-change biointerface that responds to the cooperative stimulation of light and DNA by changing the conformation of DNA structures to achieve programmable activation of the interface. We construct the biointerface by the combination of a fluorescent dye-labeled hairpin DNA with a photoresponsive molecule, which is cleaved by the first stimulation of UV light (stimulus 1, S1 ) to expose the toehold domain. Then, the biointerface gets color changed through the toehold-mediated DNA strand displacement reaction with the second stimulation of the invading DNA probe (stimulus 2, S2 ). Moreover, the transformation efficiency of the biointerface increased from 6.8 to 64% with an increase of S1 from 0 to 600 s in the presence of S2 . Also, after the stimulation of S1, the effective transformation efficiency was also tuned from 5.3 to 72% by different amounts of S2 in the complex matrix, indicating the potential for a high response in real-world settings.