Metal-Doped and Surface-Functionalized ZIF-8 Nanoplatforms for Antimicrobial Applications in Food and Environmental Systems

Zeolitic imidazolate framework-8 (ZIF-8) is one of the most extensively studied metal–organic frameworks due to its high surface area, tunable porosity, chemical stability, and intrinsic antimicrobial activity. Recent research has focused on engineering ZIF-8 through metal doping and surface functionalization to enhance its physicochemical performance and expand its applications in food safety and environmental systems. Metal-doped ZIF-8 incorporating Cu2+, Fe2+/Fe3+, Ag+, or Mn2+ improves reactive oxygen species generation, enables controlled metal-ion release, and promotes synergistic bactericidal mechanisms against both Gram-positive and Gram-negative pathogens. In parallel, surface modification using biopolymers such as hyaluronic acid, chitosan, alginate, and polyethylene glycol enhances colloidal stability, reduces cytotoxicity, modulates surface charge, and improves adhesion to food-contact surfaces. These combined strategies enable the development of multifunctional nanoplatforms with sustained antimicrobial activity, improved aqueous dispersibility, and compatibility with food packaging, sanitizers, and water treatment systems. This review summarizes recent advances in synthesis strategies, structure–property relationships, antimicrobial and antibiofilm mechanisms, and environmental safety considerations. Key challenges, including scalability, regulatory acceptance, stability, and long-term ecotoxicological impact, are discussed, along with perspectives on stimuli-responsive systems, essential oil encapsulation, and smart antimicrobial coatings.