Lysozyme-mediated fabrication of well-defined core-shell nanoparticle@metal-organic framework nanocomposites

We report a versatile strategy based on self-assembled lysozymes (LYZs) to prepare core-shell nanocomposites with nanoparticles (NPs) in metal-organic frameworks (MOFs). We first demonstrated that LYZs can readily self-organize into a robust coating layer with abundant functional groups on the surfaces of various NPs, making it possible to mediate the heterogeneous nucleation and growth of MOFs for the structural integration of a broad range of NPs and functional MOFs. Two kinds of core-shell NP@MOF nanocomposites with monocrystalline-shell and polycrystalline-shell structures are obtained depending on the size of the NPs. The readily tunable structures added additional possibilities to tailor the functionalities of the nanocomposites by sandwiching nanostructures between the core and shell. When coupled with soft lithography, the LYZ-based method allows for fabricating the arrays of carbon dot (CD)@Tb-MOFs on a microscope glass slide with micro-sized resolution within minutes, which unlocked a possible opportunity for precisely engineering NP@MOF arrays on solid substrates. The proposed method shows competitive advantages including ease of interfacial functionalization, simple and mild conditions, and structural tunability for constructing NP@MOF nanocomposites, which have great potential applications in many fields such as catalysis, sensors, biomedicine, and tissue engineering.