Urinary‐based infections affect millions of people worldwide. Such bacterial infections are mainly caused by Escherichia coli (E. coli) biofilm formation in the bladder and/or urinary catheters. Herein, the authors present a hybrid enzyme/photocatalytic microrobot, based on urease‐immobilized TiO2/CdS nanotube bundles, that can swim in urea as a biocompatible fuel and respond to visible light. Upon illumination for 2 h, these microrobots are able to remove almost 90% of bacterial biofilm, due to the generation of reactive radicals, while bare TiO2/CdS photocatalysts (non‐motile) or urease‐coated microrobots in the dark do not show any toxic effect. These results indicate a synergistic effect between the self‐propulsion provided by the enzyme and the photocatalytic activity induced under light stimuli. This work provides a photo‐biocatalytic approach for the design of efficient light‐driven microrobots with promising applications in microbiology and biomedicine.

This paper presents an effective hydrothermal route to decorate various types of anodic 1D TiO 2 nanotubes (TiO 2 NTs) with magnetite nanoparticles (Fe 3 O 4 NPs), yielding a magnetically guidable and active photocatalyst. A unique portfolio of TiO 2 NTs including single-tube, single-walled, and double-walled ones was used. Optimal conditions for uniform decoration of these nanotubes by Fe 3 O 4 NPs (two different loadings) using a wet chemical synthesis based on an oleate hydrothermal approach were found. The resulting TiO 2 NTs@Fe 3 O 4 NPs were shown to be superparamagnetic at room temperature, to have a stable connection of NPs to NTs, and to have good magnetic response under an external applied magnetic field. The as-prepared materials were used as magnetically guidable photocatalyst for the decomposition of a model dye (methylene blue). Fe 3 O 4 NPs enhanced the photocatalytic activity of TiO 2 NTs under visible light. In principle, TiO 2 NTs@ Fe 3 O 4 NPs could be used as magnetically guidable drug delivery system with photoinduced drug release.