Visible-Light-Driven Single-Component BiVO₄ Micromotors with the Autonomous Ability for Capturing Microorganisms

Abstract

Light-driven micro/nanomotors represent the next generation of automotive devices that can be easily actuated and controlled by using an external light source. As the field evolves, there is a need for developing more sophisticated micromachines that can fulfill diverse tasks in complex environments. Herein, we introduce single-component BiVO4 micromotors with well-defined micro/nanostructures that can swim both individually and as collectively assembled entities under visible-light irradiation. These devices can perform cargo loading and transport of passive particles as well as living microorganisms without any surface functionalization. Interestingly, after photoactivation, the BiVO4 micromotors exhibited an ability to seek and adhere to yeast cell walls, with the possibility to control their attachment/release by switching the light on/off, respectively. Taking advantage of the selective motor/fungal cells attachment, the fungicidal activity of BiVO4 micromotors under visible illumination was also demonstrated. The presented star-shaped BiVO4 micromotors, obtained by a hydrothermal synthesis, contribute to the potential large-scale fabrication of light-powered micromotors. Moreover, these multifunctional single-component micromachines with controlled self-propulsion, collective behavior, cargo transportation, and photocatalytic activity capabilities hold promising applications in sensing, biohybrids assembly, cargo delivery, and microbiological water pollution remediation.

Recent Advances in Nano‐ and Micromotors

“…In addition, Villa and collaborators synthesized microscaled BiVO 4 stellations that are prone to be stimulated by light, and that can capture microorganisms for water pollution remediation . In this case, the mechanism of propulsion was based on the photochemical reaction of H 2 O 2 , and the asymmetrical generation of chemical species yielded in self‐propulsion.…”

“…In addition, Villa and collaborators synthesized microscaled BiVO 4 stellations that are prone to be stimulated by light, and that can capture microorganisms for water pollution remediation. [53] In this case, the mechanism of propulsion was based on the photochemical reaction of H 2 O 2 , and the asymmetrical generation of chemical species yielded in self-propulsion. The maximum velocity was found to be 5 (±1) µm s −1 for 0.025 wt% H 2 O 2 and two types of motion were recorded; "planar" motion with linear net displacement for single-fourpointed microstars, and "stand-up" motion with circular trajectories and almost no net displacement for twin-four-pointed microstars.…”

Tailoring Metal/TiO2 Interface to Influence Motion of Light‐Activated Janus Micromotors

“…In other words, their velocities can be controlled not only by adding H 2 O 2 fuel but also by increasing light intensity . In addition to TiO 2 , hematite (Fe 2 O 3 ) and BiVO 4 have been used as base templates to fabricate earlier generation light‐powered micromotors, due to their wide bandgap semiconducting properties. Recently, photoactive quantum dots are attracting great attention among scientists for the preparation of visible‐light‐driven micromotors .…”

Visible‐Light‐Driven Janus Microvehicles in Biological Media

“…[14] Cu 2 O micromotors doped with carbon nanotubes can be efficiently driven by visible-light-triggered photocatalytic reactions of glucose. [16] Yet, applications have been mostly directed to environmental remediation, and only near-infrared light has been exploited for triggered drug-release schemes. [16] Yet, applications have been mostly directed to environmental remediation, and only near-infrared light has been exploited for triggered drug-release schemes.…”