Fabrication of supramolecular self-assembly of the Schiff base complex for improving bioavailability of aldehyde-containing plant essential oil

•pH-Responsive supramolecular self-assembly of cinnamaldehyde (Cin) was constructed.•The obtained self-assembly was almost nonvolatile and had excellent surface activity.•The self-assembly with desirable stability could respond to the acidity environments.•The self-assembly exhibited good activities against different plant pathogenic fungi.•The self-assembly had environmental compatibility and biosafety to the plants.