A facile construction method for pH and oxidation dual-responsive assembly based on ferrocene-modified chitooligosaccharide

Here, we present a novel and facile method for constructing “snowflake-like” assemblies that respond to external stimuli, similar to snowflakes in nature, via the self-organization of ferrocene-modified chitooligosaccharide (FcCOS) in an acid aqueous solution. Interestingly, the snowflakes were sensitive to pH and redox stimuli. They not only formed irregular network-like aggregates when the pH was adjusted to 7.0, they also gradually transformed into loose snowflakes with holes after exposure to air for 5 d and totally collapsed after treatment with hydrogen peroxide. Due to their interesting responses to pH and oxidation, these assemblies are a very interesting and promising system for biomaterial applications.