Anisotropic α-Fe₂O₃/AgAu/Polydopamine Nanostructures for Photothermally Enhanced Antibacterial Applications

Abstract

Multifunctional photothermal nanomaterials offer notable opportunities for antimicrobial therapy due to their excellent antibacterial activities without leading to drug resistance. Herein, we report a facile one-step strategy for fabricating anisotropic corn-like α-Fe2O3/AgAu/polydopamine (PDA) nanospindles with photothermally enhanced antibacterial performance. The AgAu bimetallic nanocrystals sandwiched between the α-Fe2O3 core and the PDA shell are achieved by simultaneous reduction from AgNO3 and HAuCl4 during the oxidative polymerization of dopamine and galvanic replacement reaction between the obtained Ag nanocrystals and Au precursor. The inner nanostructure and atom ratio of AgAu bimetallic nanocrystals can be modulated by varying the experimental parameter, thus further controlling the photothermal activities. In comparison to α-Fe2O3/Au/PDA, Fe2O3/Ag1.7Au0.8/PDA (50 μg/mL) has a better photothermal conversion effect (60.69%). Moreover, the α-Fe2O3/Ag1.7Au0.8/PDA nanospindle exhibits moderate antibacterial activity, which may be derived from Ag+ release. Under application of near-infrared light irradiation, the corn-like α-Fe2O3/Ag1.7Au0.8/PDA nanospindles (50 μg/mL) exhibit a photothermally enhanced sterilization effect against both Escherichia coli and Staphylococcus aureus (99.99%). This “Ag+ release–photothermal” coupling sterilization method provides a simple synergistic antimicrobial therapy strategy, which possesses great promise for future nanomedicine against bacteria in water treatment.

Recent Development and Applications of Polydopamine in Tissue Repair and Regeneration Biomaterials

“… 171 The strategy of combining PDA and metal ion materials is also applied to the disinfection of water bodies. 172 , 173 The design ideas of materials in different fields may bring new inspiration to the design of wound antimicrobial materials.…”

A Triple-Functional Antibacterial Platform Based on Quaternized Ru(II) Complex-Loaded MXene Composites

“…Nanomaterials have a wide range of applications in the field of photothermal antibacterial activity due to their distinctive optical and thermal properties. Examples include metal nanoparticles, − oxide nanoparticles, , sulfide nanoparticles , and carbon nanomaterials. − For instance, Fang et al manufactured anisotropic corn-shaped α-Fe 2 O 3 /AgAu/polydopamine nano spindle structures with enhanced photothermal antibacterial properties by adjusting the internal nanostructure and atomic ratios of AgAu bimetallic nanocrystals. This material exhibited enhanced bactericidal effects through photothermal enhancement.…”