Elucidating Interactions that Govern DNA Incorporation into Metal–Phenolic Networks

Abstract The application of metal–phenolic networks (MPNs) in materials engineering has been driven by the diverse interactions that polyphenols exhibit with various substrates and biomolecules, paving the way for their use in drug delivery, sensing, and coatings. In particular, the interaction of MPNs with DNA is of interest, owing to the potential of DNA molecules to provide biofunctionality and tunable properties in advanced phenolic materials. Despite previous studies on MPNs and DNA nano/macro structures, there is a limited understanding of MPN–DNA interactions and how these can be exploited in materials assembly. Herein, we examine and elucidate the interactions that drive the assembly of MPNs and DNA through layer-by-layer (LbL) deposition on planar and particle substrates. While polyphenols and DNAs can interact directly, through using a suite of metal ions and polyphenols, we demonstrate the essential role of coordination chemistry to enhance the efficiency of DNA loading and LbL assembly. Ionic interactions and metal coordination are essential for preserving LbL hollow capsule integrity, as demonstrated by the stability of the MPN–DNA multilayers at various ionic strengths. This study improves our understanding of MPN–DNA interactions and highlights the potential of fabricating scalable MPN–DNA systems with nucleic acid encapsulation and elution properties that can be exploited as a platform for sensing or gene delivery.