One-Step Assembly of Coordination Complexes for Versatile Film and Particle Engineering

TLDR

Facile, versatile thin‑film and particle engineering is highly sought after, yet few methods can conformally coat diverse substrates. The study reports a one‑step coating of diverse interfaces using natural polyphenol–Fe(III) coordination complexes. Film formation begins with polyphenol adsorption and is guided by pH‑dependent, multivalent coordination bonding. Aqueous deposition rapidly produces diverse, disassemblable thin films and capsules on planar, inorganic, organic, and biological templates, and the process is low‑cost, scalable, pH‑responsive, and cytotoxicity‑free, making it suitable for biomedical and environmental uses.

Abstract

The development of facile and versatile strategies for thin-film and particle engineering is of immense scientific interest. However, few methods can conformally coat substrates of different composition, size, shape, and structure. We report the one-step coating of various interfaces using coordination complexes of natural polyphenols and Fe(III) ions. Film formation is initiated by the adsorption of the polyphenol and directed by pH-dependent, multivalent coordination bonding. Aqueous deposition is performed on a range of planar as well as inorganic, organic, and biological particle templates, demonstrating an extremely rapid technique for producing structurally diverse, thin films and capsules that can disassemble. The ease, low cost, and scalability of the assembly process, combined with pH responsiveness and negligible cytotoxicity, makes these films potential candidates for biomedical and environmental applications.