Work

Ultrasensitive chemotaxis of urease-powered micromotors with reversible regulation by micromolar chemical modulators

Year: 2026

Type: article

Abstract: Inspired by the chemotactic navigation of biological cells and microorganisms, enzyme-powered micromotors have emerged as promising autonomous systems that convert chemical energy into directional motion. However, the ultrasensitive regulation of their chemotactic responses by low-concentration chemical modulators remains largely unexplored. Herein, we report urease-functionalized micromotors capable of chemotaxis in a three-inlet microfluidic device that generates well-defined lateral urea gradients. The micromotors exhibited self-propulsion driven by urease-catalyzed urea decomposition, and their motility was reversibly modulated by Ag + /DTT-mediated chemical regulation at micromolar levels. Under lateral urea gradients, the micromotors exhibited positive chemotaxis and migrated preferentially toward the substrate-rich stream. Notably, this chemotactic response was suppressed by 1 μM Ag + and restored by 16 μM DTT. The Janus micromotors showed a stronger chemotactic response than their non-Janus counterparts, with transverse displacements of 13.92 ± 0.85 and 10.16 ± 1.92 μm, respectively, highlighting the role of structural asymmetry in converting substrate gradients into directional migration. Furthermore, increasing flow velocity weakened chemotactic migration by restricting the gradient development and shortening the residence time. These results provide a controlled microfluidic platform for evaluating enzyme-powered chemotaxis and provide quantitative insights into how chemical modulators, particle architecture, and flow dynamics jointly govern the ultrasensitive navigation of micromotors in chemically heterogeneous environments.

Source: Applied Materials Today

DOI: 10.1016/j.apmt.2026.103456

Authors: Wenjun Chen, Yunyi Liu, Yinuo Song, Shuhuai Wang, Xing Ma

Institution: Harbin Institute of Technology

Language: English

Topic: Micro and Nano Robotics

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,400

Funders: Science, Technology and Innovation Commission of Shenzhen Municipality, Major Projects of Guangdong Education Department for Foundation Research and Applied Research, Shenzhen Science and Technology Innovation Program, Basic and Applied Basic Research Foundation of Guangdong Province