A research team led by Hong Kong Baptist University (HKBU) has achieved a significant advancement in environmental and health technology by developing a multifunctional nanorobot. This innovative device, equipped with silver and gold nanorods, aims to enhance pollutant degradation and eliminate harmful bacteria, all while navigating through magnetic fields. The team envisions wide-ranging applications for this nanorobot in antibacterial treatments, sewage management, and biomedicine.
Chemical pollution, pathogenic bacteria, and biofilms—clusters of microorganisms trapped in a slimy matrix—pose major threats to public health. Although various nanoplatforms with catalytic and antibacterial properties have been proposed, creating a remotely controllable nanorobot that offers precise targeting and propulsion has proven challenging.
Under the guidance of Professor Ken Leung Cham-fai from HKBU’s Department of Chemistry, the team collaborated with scientists from the University of Science and Technology of China, Hefei University of Technology, and the Dongcheng branch of the First Affiliated Hospital of Anhui Medical University. Their nanorobot is engineered to break down organic pollutants, exhibit antibacterial properties, and eliminate biofilms. The significant findings of this research have been published in the esteemed journal Advanced Healthcare Materials.
Structure and Functionality of the Nanorobot
The multifunctional nanorobot features a hollow spherical structure with the following key components:
- Core: Composed of iron oxide, this magnetic material allows precise control of the nanorobot’s movements via magnetic fields, enabling navigation along predetermined routes.
- Middle Layer: Made up of silver and gold bi-metallic nanorods, this layer acts as a catalyst for chemical reactions that degrade organic pollutants while inhibiting or disrupting bacterial growth.
- Outer Layer: Crafted from polydopamine, a biocompatible material that protects and stabilizes the inner layers.
- Cavity and Mesoporous Structure: This design allows the nanorobot to function as a drug carrier.
Efficacy in Pollutant Degradation
To evaluate the nanorobot’s effectiveness, researchers created miniature simulated wastewater environments. Driven by magnetic forces, the nanorobots moved to specific chambers and significantly reduced the levels of 4-nitrophenol—an organic pollutant—and methylene blue—an industrial dye.
In addition to pollutant degradation, the nanorobot demonstrated impressive antibacterial capabilities. With zinc phthalocyanine loaded onto the nanorobot, the team tested its effects against the bacteria Escherichia coli and Staphylococcus aureus under different conditions. When employing magnetic fields alongside light sources like near-infrared lasers and xenon lamp irradiation, the nanorobot achieved an astounding 99.99% inhibition of bacterial proliferation.
The nanorobot’s magnetic propulsion also allowed it to effectively disrupt and remove bacterial biofilms, showcasing its potential to address biofilm-related infections in confined spaces such as catheters.
Professor Ken Leung Cham-fai remarked, “Our research results show that the multifunctional nanorobot developed by our research team exhibits precise catalytic capabilities, high antibacterial activity, and effective biofilm removal properties. Its mobility, navigated by magnetic fields, allows for pollutant degradation and antibacterial activities to be conducted in a controlled and effective manner. This nanorobot holds substantial promise for applications in sewage treatment, biomedicine, and beyond.”
This groundbreaking innovation marks a significant step forward in tackling critical challenges in public health and environmental management, underscoring the potential for future advancements in nanotechnology.
