Ultrasound-assisted synthesis of a ZnO–Te/TeO2 nanocomposite for multidrug-resistant microorganism and biofilm eradication

Abstract

The spread of multidrug-resistant (MDR) pathogens demands antimicrobial materials that combine tunable surface chemistry with durable, non-antibiotic kill mechanisms. We reported a sonication–freeze–dry route to hybrid ZnO nanorod-decorated Te/α-TeO₂ sheets and demonstrated that interfacial strain-engineering at the ZnO–Te/TeO₂ heterointerface enhances antimicrobial potency across Gram-negative, Gram-positive, and fungal MDR strains. Structural analysis shows a two-phase Te/α-TeO₂ host (∼68% Te: ∼32% α-TeO₂) whose oxide sublattice accumulates microstrain and defects as ZnO loading increases (α-TeO₂: D_min ≈ 39.8 nm, ε_max ≈ 0.384% at 40% ZnO), while Te domains recover crystallinity at 50% ZnO, consistent with strain redistribution. The optimal formulation (Z7, 50% ZnO–Te/α-TeO₂) produced the largest inhibition zones against Klebsiella pneumoniae (36.64 ± 3.5 mm) and Escherichia coli (34.70 ± 3.6 mm), achieved a growth reduction efficiency of 96.45 ± 2.54% and 94.19 ± 1.63%, respectively, and showed an minimal inhibition concentration (MIC) of 1.95 mg mL⁻¹ (MBC 7.81 mg mL⁻¹) versus K. pneumoniae. Long-term dynamic viability analysis demonstrates complete eradication of planktonic growth within 78–90 h, depending on strain. Mechanistically, enhanced reactive oxygen species (ROS) production together with strong interfacial membrane disruption is proposed as a potential mechanism. The material's structural tunability, facile synthesis, and broad anti-MDR performance make it promising for futher applications such as hospital coatings and infection-resistant surfaces.