Cucurbit[7]uril-Mediated Supramolecular Bactericidal Nanoparticles: Their Assembly Process, Controlled Release, and Safe Treatment of Intractable Plant Bacterial Diseases.

A safe, biocompatible, and stimuli-responsive cucurbit[7]uril-mediated supramolecular bactericidal nanoparticle was fabricated by encapsulating a highly bioactive carbazole-decorated imidazolium salt ( A 1 , EC 50 = 0.647 μg/mL against phytopathogen Xanthomonas oryzae pv oryzae ) into the host cucurbit[7]uril (CB[7]), thereby leading to self-assembled topographies from microsheets ( A 1 ) to nanospheroidal architectures ( A 1 @CB[7]). The assembly behaviors were elucidated by acquired single-crystal structures, 1 H NMR, ITC, and X-ray powder diffraction experiments. Complex A 1 @CB[7] displayed lower phytotoxicity and could efficiently switch on its potent antibacterial ability via introducing a simple competitor 1-adamantanamine hydrochloride (AD). In vivo antibacterial trials against rice bacterial blight revealed that A 1 @CB[7] could relieve the disease symptoms after being triggered by AD and provide a workable control efficiency of 42.6% at 100 μg/mL, which was superior to bismerthiazol (33.4%). These materials can provide a viable platform for fabricating diverse stimuli-responsive supramolecular bactericides for managing bacterial infections with improved safety.