ZIFs-derived Zn single-atom nanozymes with integrated lactonase-, peroxidase-, and oxidase-like activities for antibacterial and antibiofilm surface engineering

Biomimetic zinc single-atom nanozymes mimicking natural lactonase were designed. • The nanozyme integrates lactonase, peroxidase, and oxidase-like activities. • Zn-Nx coordination and pore structure govern the multi-enzyme performance. • ZIF-8-Zn-SAC was immobilized onto silicone catheters via an in-situ hydrogel. • The surface exhibits synergistic quorum-quenching and antibiofilm performance. Bacterial biofilms on indwelling medical devices pose a critical challenge due to their intrinsic resistance to antibiotics and host immune defenses. Herein, a zeolitic imidazolate framework (ZIF)-derived zinc single-atom nanozyme (ZIF-8-Zn-SAC) was developed as a multifunctional catalytic material for antibacterial and antibiofilm applications. The atomically dispersed Zn-N x active sites in the N-doped carbon framework provide a biomimetic coordination environment resembling the catalytic center of natural lactonase. ZIF-8-Zn-SAC exhibited integrated lactonase-, peroxidase (POD)-, and oxidase (OXD)-like activities. Its lactonase-like activity enabled efficient degradation of N-acyl homoserine lactone signal molecules, thereby disrupting quorum sensing and suppressing Pseudomonas aeruginosa biofilm formation. Meanwhile, its POD- and OXD-like activities catalyzed the generation of reactive oxygen species from H 2 O 2 and dissolved O 2 , leading to oxidative bacterial damage. Structure-activity relationship analysis indicated that Zn-N x coordination, nitrogen species, and pore accessibility were associated with the multi-enzymatic catalytic performance. As a proof-of-concept surface engineering demonstration, ZIF-8-Zn-SAC was immobilized onto silicone catheter surfaces through an in-situ hydrogel coating strategy. The resulting nanozyme-functionalized surfaces showed effective inhibition of P. aeruginosa biofilm formation, favorable preliminary in vitro biocompatibility, and retained mechanical stability. This work provides a structure-activity-guided strategy for designing multifunctional nanozymes and highlights their potential for antibiofilm surface engineering on polymeric medical interfaces. Schematic illustration of the design and antibiofilm mechanism of ZIF-8-Zn-SAC nanozymes. ZIFs-derived Zn-N x active sites embedded in an N-doped carbon framework provide biomimetic lactonase-like activity for AHLs degradation and quorum-sensing disruption. Simultaneously, the nanozyme exhibits POD- and OXD-like activities, catalyzing ROS generation from H 2 O 2 and dissolved O 2 to induce oxidative bacterial damage. As a proof-of-concept surface engineering strategy, ZIF-8-Zn-SAC was immobilized onto silicone catheter surfaces via an in-situ hydrogel coating, enabling effective inhibition of Pseudomonas aeruginosa biofilm formation on device-relevant polymeric interfaces. Download: Download high-res image (318KB) Download: Download full-size image