One-Step Sol–Gel-Fabricated CuZn Alloy Aerogel Enabled by Cu–Zn Bimetallic Synergy for Efficient Antibacterial and Anti-Biofilm Therapy

Copper nanoparticles possess broad-spectrum antibacterial activity, and aerogels with 3D interconnected porous networks can trap bacteria and sustain metal ion release to boost bactericidal effects. Zinc is another low-toxicity antibacterial metal, and the Cu–Zn combination is predicted to generate synergistic inhibition. Herein, monometallic Cu aerogel and CuZn alloy aerogel were fabricated by a one-step method, and comparative experiments were performed to verify whether Zn alloying improves the antibacterial performance of Cu aerogel. TEM and XRD suggest the probable formation of Cu–Zn substitutional solid solution; Zn addition refined nanoparticles and relieved particle aggregation. Quantitative viability tests, agar diffusion and biofilm inhibition assays proved that CuZn alloy aerogel exhibited superior bactericidal and anti-biofilm activity against E. coli and S. aureus. Mechanistic investigations revealed that the bimetallic alloy induced strain-dependent intracellular ROS accumulation and disrupted bacterial membrane potential to cause irreversible bacterial death. DC2.4 cell tests validated its good cytocompatibility, with cell viability over 70% at 100 ppm, the concentration delivering excellent antibacterial capacity. This work explores the combined antibacterial advantages of Cu-Zn bimetallic alloy aerogel and offers a facile strategy to fabricate biocompatible metal aerogels for biomedical antibacterial applications.