Multi-stimuli responsive nanomaterials assembled from spiropyran-containing peptoids

Abstract

Stimuli-responsive tunable supramolecular assemblies are highly desirable for controlling functionalities via morphological changes and alternations in crystallinity. Here, we report that amphiphilic peptoids with a multifunctional spiropyran (SP) group assemble into responsive 2D nanosheets and 1D nanotubes through light and heat-mediated isomerization. Computational analysis by periodic density functional theory (DFT) calculations on dimers of SP and its isomer, merocyanine (MC), reveals significantly more favorable packing energetics for MC compared to SP, further supporting the high crystallinity of assemblies composed of peptoids with MC. Furthermore, we demonstrate how stimulus-responsive control over peptoid assembly crystallinity can be utilized in tuning catalytic activity in mimicking carbonic anhydrase (CA) enzymes.