Biomimetic ultrathin pepsomes for photo-controllable catalysis

Artificial vesicles for mimicking the unique structures and functions of natural organelles represent a promising scientific object in biomimicry.However,the development of the stimuli-responsive and ultrathin vesicles assembled from sequence-defined biomimetic polymers for controllable applications is still a significant challenge.Herein,we report the self-assembly of azobenzene-based amphiphilic alternating peptoids to generate photo-responsive and ultrathin peptoid vesicle(pepsomes)with an average diameter of∼180 nm.Both cryo-transmission electron microscopy(TEM)and dissipative particle dynamics simulation proved that the vesicular membrane was the ultrathin bilayer structure around∼1.6 nm.The photo-responsive ability of pepsomes was demonstrated by the reversible size changes upon the alternative irradiation with ultraviolet(UV)and visible lights,which was attributable to the photoisomerization virtue of azobenzene moiety.As a proof-of-concept,the photo-controllable catalytic action of gold nanoparticles-decorated pepsomes was evaluated toward the borohydride-mediated reduction from 4-nitrophenol to 4-aminophenol.Photo-controllable reversible and recyclable catalytic activity was effectively modulated using the alternative irradiation with UV and visible lights for five cycles.Our work provides a simple strategy to prepare stimuli-responsive and ultrathin vesicles for potential application on nanocatalysis.