Antibacterial Activity of Quantum-Confined One-Dimensional Titanate Nanofilaments

Abstract

The emergence of antimicrobial resistance demands fundamentally new classes of antibacterial materials that operate through mechanisms distinct from conventional chemical or photodynamic pathways. Here, we introduce quantum-confined, one-dimensional lepidocrocite titanate nanofilaments (1DL NFs) as a previously unexplored inorganic nanomaterial platform that inactivates bacteria through direct contact-mediated membrane disruption. The 1DL-Ti NFs exhibit potent antibacterial activity against Escherichia coli, Bacillus subtilis, and Listeria innocua, achieving ∼96–99% inactivation within 4 h under ambient light and ∼85% in the dark, revealing light-independent efficacy. Multiparametric analyses─including reactive oxygen species assays, flow cytometry, and high-resolution electron microscopy─demonstrate a unique physical mechanism by which 1DL NFs result in membrane impalement, cell entrapment, and rapid biofilm-like agglomeration, distinct from ion- or reactive oxygen species-driven bactericidal pathways. Metal-ion release studies confirmed negligible leaching, ruling out ion-mediated toxicity. This “all-surface” architecture, enabled by the atomically thin one-dimensional structure of the NFs, differentiates them from conventional TiO2 nanocrystals and promotes strong interfacial contact with bacterial membranes. The synthesis is solution-based, low-temperature, highly scalable, and tolerant to the presence of several interlayer cations, providing modularity and manufacturability. These findings establish 1DL NFs as a new class of inorganic antibacterial materials with transformative potential for smart antimicrobial coatings, biomedical interfaces, water purification, and food-safety applications.