Installing Logic Gates to Multiresponsive Supramolecular Hydrogel Co-assembled from Phenylalanine Amphiphile and Bis(pyridinyl) Derivative

Recently, logic gates based on multiresponsive hydrogel systems are attractive because of their potential biological applications. A quite simple supramolecular hydrogel co-assembled from phenylalanine-based amphiphile (LPF2) and bis(pyridinyl) derivative (AP) is constructed. The co-assembled hydrogel exhibited a macroscopic gel-sol transition in response to four distinct input stimuli: temperature, acid, base, and light. A set of techniques including microscopic, spectroscopic, and rheological measurements demonstrate this performance and confirm that the hydrogel is formed through intermolecular hydrogen bonds between amide/pyridine moieties and carbonyl groups. On the basis of its mutiple-stimulus responsiveness, installing gel-based supramolecular logic gates (OR and XOR) is achieved. It may promote the possibility to develop smart soft materials, such as gels, that can be used as tools releasing a drug quantitatively by rational design and fine control of the external stimuli.