Flavin based supramolecular gel displaying multi-stimuli triggered sol–gel transition

Abstract

Herein, we report the design and synthesis of an amphiphilic flavin analogue as a robust low molecular weight gelator involving minimal structural modification. Four flavin analogues were evaluated for their gelation capabilities and the flavin analogue with antipodal positioning of the carboxyl and octyl functionalities was found to be the most efficient gelator with the minimum gelation concentration being as low as 0.03 M. A wide range of solvents were used for gelation studies suggesting its widespread applicability. Morphological, photophysical and rheological characterization studies were performed to fully characterize the nature of the gel. Interestingly, reversible multiple stimuli responsive sol–gel transition was observed with changing pH and redox activity, while metal screening showed specific transition in the presence of ferric ions. The gel was able to differentiate between ferric and ferrous species with well-defined sol–gel transition. The current results potentially offer a redox-active flavin-based material as a low molecular weight gelator for the development of next-generation materials.