Selective Metal–Phenolic Assembly from Complex Multicomponent Mixtures

Abstract

Selective self-assembly in multicomponent mixtures offers a method for isolating desired components from complex systems for the rapid production of functional materials. Developing approaches capable of selective assembly of "target" components into intended threedimensional structures is challenging because of the intrinsically high complexity of multicomponent systems. Herein, we report the selective coordination-driven self-assembly of metal-phenolic networks (MPNs) from a series of complex multicomponent systems (including crude plant extracts) into thin films via metal chelation with phenolic ligands. The metal (Fe III) selectively assembles low abundant phenolic components (e.g., myricetrin and quercetrin) from plant extracts into thin films. This selective metal-phenolic assembly is independent of the substrate properties (e.g., size, surface charge and shape). Moreover, the high selectivity of our method is consistent across different target phenolic ligands in model mixtures, even though each individual component can form thin films from single component systems. A computational simulation of film formation suggests that the driving force for the selective behavior stems from differences in the number of chelating sites in the phenolic structures. The MPN films are shown to demonstrate improved antioxidant properties compared with the corresponding phenolic compounds in their free form, therefore exhibiting potential as free-standing antioxidant films.

Expanding the Toolbox of Metal–Phenolic Networks via Enzyme‐Mediated Assembly

“…After incubation with Res'-iron@PS particles for 30 min, DPPH solutions changed from purple to yellow,a nd the UV-vis absorbance at 515 nm decreased (Figure 5b), indicating the reduction of DPPH radicals. [32] Further investigation showed that 84-94 %o fD PPH was consumed by Res'-iron@SiO 2 particles,R es'-iron@PS particles,a nd Res'-iron@poly(methyl methacrylate) (PMMA) particles (Figure 5c,F igure S26), demonstrating the radical scavenging ability of the coatings on different substrates. Similarly,t he GFP'-iron@SiO 2 particles showed green fluorescence (Figure 5e,f), and considering the biocompatibility of the GFP'-iron coatings ( Figure S27), these particles could potentially be used for biomedical imaging.I na ddition, the Cat'-iron@SiO 2 particles could decompose reactive oxygen species by catalyzing H 2 O 2 to H 2 Oa nd O 2 ,a se videnced by the generation of O 2 (Figure 5h,i).…”

Expanding the Toolbox of Metal–Phenolic Networks via Enzyme‐Mediated Assembly

“…To demonstrate the resistance of the Res′‐iron‐coated particles (Res′–iron@particles) against attack from radicals, the 2,2′‐diphenyl‐picrylhydrazyl (DPPH) assay was used. After incubation with Res′‐iron@PS particles for 30 min, DPPH solutions changed from purple to yellow, and the UV‐vis absorbance at 515 nm decreased (Figure b), indicating the reduction of DPPH radicals . Further investigation showed that 84–94 % of DPPH was consumed by Res′–iron@SiO 2 particles, Res′–iron@PS particles, and Res′–iron@poly(methyl methacrylate) (PMMA) particles (Figure c, Figure S26), demonstrating the radical scavenging ability of the coatings on different substrates.…”

Microemulsion-Assisted Templating of Metal-Stabilized Poly(ethylene glycol) Nanoparticles

“…The spectra of the PEG-gallol/Mn II NPs featured a new absorption peak in the range of 350-600 nm, which was absent in the spectrum of free PEGgallol (Figure 1b). This new peak was attributed to the ligand-to-metal charge-transfer (LMCT) band of gallol/Mn II , 25 indicating the presence of gallol-Mn II coordination in the PEG NPs. Bisto tris-type coordination was previously reported for PEG-gallol/Fe III films based on the LMCT band at 520 nm.…”