Guest-induced supramolecular helices and its application in L-Arg detection and L-Arg controlled reversible morphology modulation

A novel AIE supramolecular polymer (BPK) was synthesized by bis(2-hydroxy-1-naphthaldehyde) terephthalo hydrazone functionalized pillar [5]arene and cross-linked using a bis(4.4-dipyridinium salt)cross-linker via host-guest complexation. BPK exhibited strong aggregation-induced emission (AIE) in binary solutions of DMSO/H2O. BPK could be an AIE-based sensor with specific fluorescence sensing ability for L-Arg in water. The detection limit of BPK for L-Arg was 3.95 × 10−7 M, and other amino acids did not interfere with the sensing process. Moreover, in a pure DMSO solvent, BPK can self-assemble into a fibrous structure of the right-hand spiral by guest-induced supramolecular helices. At 80 % water content, BPK undergoes a morphological transformation into supramolecular polymer. Intriguingly, BPK exhibits a reversible transformation from a polymer to a nanosphere through the alternating addition of trifluoroacetic acid and arginine. Additionally, the fluorescence of BPK demonstrates an "on-off" switch. This phenomenon is attributed to the formation and disruption of intermolecular hydrogen bonds. The reversible manipulation of polymer materials' morphology and optical properties holds significant potential in biomedicine and smart materials. An efficient guest-induced supramolecular helix was developed for the simultaneous detection of amino acids and precise morphology control by amino acids. [Display omitted] •In this study, a novel AIE supramolecular polymer was constructed by host-guest interaction.•We have constructed a highly sensitive sensing platform for arginine through multi-hydrogen bonding interactions.•We have achieved precise modulation of the morphology of supramolecular polymers by alternating adding L-Arg and TFA.•We report a novel supramolecular helical structure that can be realized by adding a guest K to the host BP.