Janus Microgel Robots for Actively Boosting Catalytic Efficiency and Recovery of Living Materials

Leveraging living materials such as algae as sustainable photocatalytic platform is highly promising for mitigating antibiotic water pollution; however, they are confronted with low catalytic efficiency and difficulty in recovery, as imposed by their passive, static working mode. Herein, we report a Janus microgel robot (JMR) that features the integration of magnetic-controlled mobility and living photocatalytic function, allowing for substantially boosting antibiotic degradation efficiency and efficient recovery in an actively magnetic-controlled manner. The key to the JMR lies in harnessing gas shear microfluidic technique to manipulate the spatial distribution of TiO2-Chlorella pyrenoidosa and Fe3O4 phases into a Janus architecture, followed by gel encapsulation to prevent cell leakage. Under simulated sunlight, the JMR system achieves 77% antibiotic degradation within 10 h, which is 10 times that of the free C. pyrenoidosa (7.6%). Moreover, we demonstrate that the JMR can be imparted with enhanced degradation efficiency by 10.6% and over 95% effectiveness through 3 consecutive operational cycles in actively magnetic-controlled mode. This work establishes a prototype for sustainable environmental biorobots and provides a novel strategy for photocatalytic-biological hybrid system design, advancing the next-generation living materials for water treatment.