Active Light‐Powered Antibiofilm ZnO Micromotors with Chemically Programmable Properties

Abstract

Bacterial biofilms are multicellular communities firmly attached to solid extracellular substrates. They are considered the primary cause of huge economic losses, from medicine due to medical implants’ failure to large infrastructure due to enhanced pipe corrosion. Therefore, their eradication is highly desirable. Here, the preparation of ZnO self‐propelled micromotors is reported, programming their morphology and motion properties through Ag doping. The ZnO:Ag micromotors actively move upon light irradiation via a self‐electrophoretic mechanism, showing excellent light‐controlled on/off switching motion. At the same time, the rapid and effective removal of both gram‐positive and gram‐negative bacteria biofilms from the solid surface is demonstrated, exploiting the well‐known antibacterial activity of both Ag and ZnO as well as the enhanced diffusion of the micromotors. The new concept for the low‐cost and scalable preparation of chemically programmable Ag‐doped ZnO micromotors here illustrated opens a new route toward the formulation of a new class of light‐driven semiconducting self‐propelled micromotors for environmental applications.

Micro‐/Nanorobots in Antimicrobial Applications: Recent Progress, Challenges, and Opportunities

“…Lately, they have presented zinc oxide/silver micromotors for bacterial biofilm eradication in water (Figure 5B). [ 42 ] The asymmetric micromotor undergoes self‐electrophoretic motion under UV‐light irradiation, which enhances the ROS production from the catalytic reaction of ZnO and the diffusion of antimicrobial nanosilver, thus promoting the antibiofilm efficacy. In addition, photothermal‐powered micromotors take advantage of another type of light‐induced propulsion by photothermal effects, employing the surrounded heat energy converted from light and conducting self‐propulsion along the thermal gradient.…”

“…Reproduced with permission. [ 42 ] Copyright 2021, Wiley‐VCH GmbH. C) Scheme of lysozyme modified AuNW for pathogen killing through ultrasound propulsion.…”

“…[ 27–29 ] locomotion is the fundamental behavior of MNRs and is also critical for task execution. Based on the propulsion mode, antibacterial micromotors mainly can be classified into two categories: self‐driving, [ 30–36 ] and external field propulsion, including magnetic, [ 37–39 ] light, [ 40–42 ] and ultrasonic propulsion. [ 43,44 ] The kinematic behavior of micromotors can enhance fluid mixing and facilitate the integration with appropriate bactericidal strategies.…”

“…ZnO: Ag micromotors: Reproduced with permission. [ 42 ] Copyright 2021, Wiley‐VCH GmbH. Ab nanobot: Reproduced with permission.…”

Plasmonic-magnetic nanorobots for SARS-CoV-2 RNA detection through electronic readout

“…Micro/nanorobots are small-scale artificial machines that rationally designed to perform predefined tasks by converting various energies into mechanical motion and various chemical triggers to perform the designed action [1] , [2] , [3] , [4] , [5] . Along with their advanced performances, such as autonomous self-propelling, precisely maneuverable speed and direction, and remote actuation, these tiny robotic systems have demonstrated great potential for a wide range of applications, including sensing [6] , [7] , [8] , targeted delivery [ 2 , 5 ], microsurgery [ 9 , 10 ], biofilm disruption [ 11 , 12 ], and environmental remediation [ 13 , 14 ]. In particular, micro/nanorobots have been exploited to enhance the analytical performance in biosensing applications [ 6 , 7 ].…”