Less than 1% of Earth's freshwater reserves is accessible. Industrialization, population growth and climate change are further exacerbating clean water shortage. Current water-remediation treatments fail to remove most pollutants completely or release toxic by-products into the environment. The use of self-propelled programmable micro- and nanoscale synthetic robots is a promising alternative way to improve water monitoring and remediation by overcoming diffusion-limited reactions and promoting interactions with target pollutants, including nano- and microplastics, persistent organic pollutants, heavy metals, oils and pathogenic microorganisms. This Review introduces the evolution of passive micro- and nanomaterials through active micro- and nanomotors and into advanced intelligent micro- and nanorobots in terms of motion ability, multifunctionality, adaptive response, swarming and mutual communication. After describing removal and degradation strategies, we present the most relevant improvements in water treatment, highlighting the design aspects necessary to improve remediation efficiency for specific contaminants. Finally, open challenges and future directions are discussed for the real-world application of smart micro- and nanorobots.

• Klíčová slova
• Molecular machines and motors,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The coronavirus disease 2019 (COVID-19) has prompted an urgent demand for nanotechnological solutions towards the global healthcare crisis, particularly in the field of diagnostics, vaccines, and therapeutics. As an emerging tool for nanoscience and technology, micro/nanorobots have demonstrated advanced performances, such as self-propelling, precise maneuverability, and remote actuation, thus hold great potential to provide breakthroughs in the COVID-19 pandemic. Here we show a plasmonic-magnetic nanorobot-based simple and efficient COVID-19 detection assay through an electronic readout signal. The nanorobots consist of Fe3O4 backbone and the outer surface of Ag, that rationally designed to perform magnetic-powered propulsion and navigation, concomitantly the probe nucleic acids transport and release upon the hybridization which can be quantified with the differential pulse voltammetry (DPV) technique. The magnetically actuated nanorobots swarming enables enhanced micromixing and active targeting, thereby promoting binding kinetics. Experimental results verified the enhanced sensing efficiency, with nanomolar detection limit and high selectivity. Further testing with extracted SARS-CoV-2 viral RNA samples validated the clinical applicability of the proposed assay. This strategy is versatile to extend targeting various nucleic acids, thus it could be a promising detection tool for other emerging pathogens, environmental toxins, and forensic analytes.

• Klíčová slova
• Biosensing, COVID-19, Iron oxides, Micromotors, Transversal rotating magnetic field,
• Publikační typ
• časopisecké články MeSH

Manipulation and navigation of micro and nanoswimmers in different fluid environments can be achieved by chemicals, external fields, or even motile cells. Many researchers have selected magnetic fields as the active external actuation source based on the advantageous features of this actuation strategy such as remote and spatiotemporal control, fuel-free, high degree of reconfigurability, programmability, recyclability, and versatility. This review introduces fundamental concepts and advantages of magnetic micro/nanorobots (termed here as "MagRobots") as well as basic knowledge of magnetic fields and magnetic materials, setups for magnetic manipulation, magnetic field configurations, and symmetry-breaking strategies for effective movement. These concepts are discussed to describe the interactions between micro/nanorobots and magnetic fields. Actuation mechanisms of flagella-inspired MagRobots (i.e., corkscrew-like motion and traveling-wave locomotion/ciliary stroke motion) and surface walkers (i.e., surface-assisted motion), applications of magnetic fields in other propulsion approaches, and magnetic stimulation of micro/nanorobots beyond motion are provided followed by fabrication techniques for (quasi-)spherical, helical, flexible, wire-like, and biohybrid MagRobots. Applications of MagRobots in targeted drug/gene delivery, cell manipulation, minimally invasive surgery, biopsy, biofilm disruption/eradication, imaging-guided delivery/therapy/surgery, pollution removal for environmental remediation, and (bio)sensing are also reviewed. Finally, current challenges and future perspectives for the development of magnetically powered miniaturized motors are discussed.

• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH